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Research ArticleCobalt(II) and Manganese(II) Complexes of NovelSchiff Bases Synthesis Charcterization and ThermalAntimicrobial Electronic and Catalytic Features
Selma Bal and Sedat Salih Bal
Chemistry Department Faculty of Arts and Science Kahramanmaras Sutcu Imam University Avsar Kampusu46100 Kahramanmaras Turkey
Correspondence should be addressed to Selma Bal selmadagli9hotmailcom
Received 6 June 2014 Accepted 28 July 2014 Published 21 August 2014
Academic Editor Alessandro DrsquoAnnibale
Copyright copy 2014 S Bal and S S Bal This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Carbazoles containing two new Schiff bases (ZZ)-NN1015840-bis[(9-ethyl-9H-carbazole-3-yl)methylene]propane-13 diamine (L1)and (ZZ)-NN1015840-bis[(9-ethyl-9H-carbazole-3-yl)methylene]-22-dimethylpropane-13-diamine (L2) and their Co(II) and Mn(II)complexes were synthesized and characterized using various spectroscopic methods and thermal analysis which gave high thermalstability results for the ligands and their cobalt complexesThe title compoundswere examined for their antimicrobial and antifungalactivities which resulted in high activity values for the ligands and their manganese complexes Oxidation reactions carried out onstyrene and cyclohexene revealed that the complex compounds were the most effective catalysts for styrene oxidation giving goodselectivities than those of cyclohexene oxidation Electronic features of the synthesized compounds were also reported within thiswork
1 Introduction
Schiff bases and their complexes have been and are beingemployed to many reactions in synthetic chemistry In par-ticular the oxidation of alkenes is important intermediate toget new industrially important chemicals for both organicsynthesis and pharmaceutical industry Catalytic transforma-tions of hydrocarbons into valuable oxygenated derivativessuch as alcohols aldehydes and epoxides using peroxidesas oxidants have been extensively studied over the last fewdecades [1ndash5] In particular the catalysis of alkene oxidationby soluble transition metal complexes is of great interest inboth biomimetic chemistry and synthetic chemistry [6] Sofar various Schiff base complexes have been employed tocatalytic oxidation of olefins to epoxides and aldehydes andit has been proved that many Schiff base complexes gaveimproved results as catalysts for these kinds of oxidationreactions [7ndash20] In our research the synthesized Schiff basecomplexes have been searched for their potential use ascatalysts in oxidation reactions for both cyclohexene and
styrene Not only for these oxidation reactions but alsofor many kinds it is important to use eco-friendly witheasy recoverability oxidants such as H
2O2and air It is also
important that the catalysts are thermally stable enough tocarry out these kinds of reactions which generally requireelevated temperatures [21 22]
In addition their catalytic activities various Schiff baseshave also been examined for their biological activities inmany previous studies [23ndash25] This interest comes from thefact that their metal complexes can be used as antimicrobialantifungal and antitumor agents [26ndash28]
In previous studies various carbazoles containing Schiffbases and their coordination compounds have been synthe-sized characterized and examined for their different featuressuch as luminescence thermal property [29ndash33] biologicalactivity [34] and electrochemical and optical behaviour [35ndash37] and for their use as Langmuir-Blodgett film [38]
We report here total synthesis spectral and thermalcharacterization of two carbazole derived novel Schiff basesand their copper(II) and manganese(II) complexes their
Hindawi Publishing CorporationAdvances in ChemistryVolume 2014 Article ID 506851 12 pageshttpdxdoiorg1011552014506851
2 Advances in Chemistry
thermal electrochemical antimicrobial features and theireffect as catalysts in the oxidation reactions of cyclohexeneand styrene
2 Experiment
21 Materials and Instrumentation 9-Ethylcarbazole phos-phorus(V) oxychloride 13-diaminopropane and 22-dimethyl-13-diaminopropane all the solvents used andacetate salts of copper(II) andmanganese(II) were purchasedfrom Sigma Aldrich Nuclear magnetic resonance spectraof the synthesized ligands were recorded on a Bruker AV400MHz spectrometer in the solvent CDCl
3 Infrared
spectra were obtained using KBr discs on a Shimadzu 8300FTIR spectrophotometer in the region of 400ndash4000 cmminus1Ultraviolet spectra were run in ethanol on a SchimadzuUV-160A spectrophotometer Magnetic measurements werecarried out by the Gouy method using Hg[Co(SCN)
4] as
a calibrant Molar conductances of the ligands and theirtransition metal complexes were determined in MeOH(sim10minus3) at room temperature using a Jenway Model 4070conductivity meter Mass spectra of the ligand were recordedon a LCMS APCI Agilent 1100MSD spectrophotometerTheoxidation products were analyzed with a gas chromatograph(Shimadzu GC-14B) equipped with a SAB-5 capillarycolumn and a flame ionization detector Elemental analyseswere performed on a LECO CHNS 932 elemental analyzerand the metal analyses were carried out on an Ati Unicam929 Model AA spectrometer in solutions prepared bydecomposing the compounds in aqua regia and subsequentlydigesting them in concentrated HCl Thermal analysesof synthesized ligands and their metal complexes werecarried out on a Perkin-Elmer Thermogravimetric AnalyzerTGDTA 6300 instrument under nitrogen atmospherebetween the temperature ranges 30∘C and 988∘C at a heatingrate of 10∘Cmin Cyclic voltammetry was performed usingIviumStat electrochemical workstation equipped with a lowcurrent module (BAS PA-1) recorder
22 Synthesis of 9-Ethyl-9H-carbazole-3-carbaldehyde For-mulation of 9-ethylcarbazole was done by using Vilsmeierformulating agentsDMF andPOCl
3 Inside a fume cupboard
DMF (32mL 04mol) was put into a 250mL round-bottomflask placed in an ice bath Over DMF at 0∘C 32mL (032mol)POCl
3was added dropwise through a dropping funnel
Resulting solution was stirred at room temperature for 2hours To the stirring mixture 9-ethyl-9H-carbazole (8 g004mol) dissolved in 32mL DMF was slowly added Thereaction mixture was heated at 80∘C and left stirring for 24hours The resulting dark coloured mixture was poured intoslurry of crushed ice and water (250mL) The precipitatewas washed with water and extracted by CHCl
3and then
washed with n-hexane The dirty yellow precipitate wassubjected to flash column chromatography with the eluent ofethyl acetatehexane (1 10) Vilsmeier reaction always givesboth mono- and dialdehyde of the formulated carbazole[39 40] The monoaldehyde was the first product eluatedas yellowish-white crystals The dialdehyde obtained was
white solid TLC chromatography elemental analysis andspectral data confirm the purity and structure of synthesizedmono- and dialdehyde products Monoaldehyde 9-ethyl-9H-carbazole-3-carbaldehyde yield 40 mp 85ndash87∘CUV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 202(50000)210(80000) 226(30000) 264(36000) 284(95000) FT-IR(KBr cmminus1) 1591(w) 1622(w) 2850(w) 2922(w)(Ar-Hand C-H) 1681(s)(CHO) 1H NMR(400MHz CDCl
3)
101(CHO) 86 (H-4 d 119869 = 13) 816 (H-5 brd 119869 = 78) 802(H-2 dd 119869 = 85amp158) 746 (H-1ampH-8 d 119869 = 84) 756 (H-7dt 119869 = 82amp12) 735 (H-6 dt 119869 = 80amp103) 439 (2H-14 q119869 = 72) 147 (3H-15 t 119869 = 72) 13CNMR(400MHzCDCl
3)
1918(CHO) 1272(C-1) 1268(C-2) 1285(C-3) 12401(C-4)1208(C-5) 1203(C-6) 1087(C-7) 1092(C-8) 1435(C-10)1231(C-11) 1230(C-12) 1407(C-13) 379(C-14) 139(C-15)Mass spectrum (LCMS APCI) mz 2237 [M]+
23 Synthesis of the Ligands (ZZ)-NN1015840-Bis[(9-ethyl-9H-carbazol-3-yl)methylene]propane-13-diamine (L1) and (ZZ)-NN1015840-Bis[(9-ethyl-9H-carbazol-3-yl)methylene]-22-dimethyl-propane-13-diamine (L2) Inside a 100mL round-bottomflask 045 g (2mmol) 9-ethyl-9H-carbazole-3-carbaldehydewas put and dissolved in enough amount of ethanol Overthis 01 g (1mmol) diamine was added dropwise The result-ing solution was heated under reflux for four hours andleft overnight The white precipitate was recrystallized fromethanol (Figure 1)
231 (ZZ)-NN1015840 -Bis[(9-ethyl-9H-carbazole-3-yl)methylene]-propane-13-diamine (L1) Yield 80 mp 167∘C elementalanalysis found (calculated ) C 8234(8178) H 680(666)N 1201(1156) UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1)216(175000) 250(105000) 266(120000) 296(210000)310(161000) FT-IR (KBr cmminus1) 2843(w) 2920(w)2971(w) 1598(w)(Ar-H and C-H) 806(s) 740(s)(Ar-H)1637(s)(imine) Mass spectrum (LCMS APCI) mz 4852[119872 + 1]
+ 2801 [119872 minus 20453] which arises from the lossof ten hydrogen and one carbazole units leaving C
19H10N3
1H NMR(400MHz CDCl3) 744 (H-1ampH-8 d 119869 = 85)
792 (H-2 dd 119869 = 85amp15) 849 (H-4 d 119869 = 14) 815(H-5 d 119869 = 76) 728 (H-6 dt 119869 = 12amp76) 751 (H-7 dt119869 = 12amp71) 441 (H-14 q 119869 = 72) 147 (H-15 t 119869 = 72)384 (H-16ampH-18 q 119869 = 7) 226 (H-17 m 119869 = 7) 85 (imines) 13C NMR(400MHz CDCl
3) 12603(C-1) 1259(C-2)
1277(C-3) 1231(C-4) 1207(C-5) 1194(C-6) 1085(C-7)1087(C-8) 1415(C-10) 1272(C-11) 1240(C-12) 1405(C-13) 377(C-14) 138(C-15) 595(C-16ampC-18) 323(C-17)16206(imine)
232 (ZZ)-NN1015840-Bis[(9-ethyl-9H-carbazol-3-yl)methylene]-22-dimethylpropane-13-diamine (L2) Yield 75 mp115∘C elemental analysis found (calculated ) C 8211(8199) H 7530(708) N 1101(1093) UV-Vis (ethanol) (120582maxnm) (120576 Mminus1 cmminus1) 268(115000) 300(78000) 306(61000)334(99000) FT-IR (KBr cmminus1) 2973(w) 2949(w) 2867(w)2821(w) 1595(w) (Ar-H and C-H) 809(s) 747(s)(Ar-H)1646(s)(imine) Mass spectrum (LCMS APCI) mz 5143
Advances in Chemistry 3
1
23
456
7
8 10
1112
13
1415
N N
H
O
N
H
O
H
O
N
H
O
NN
NN
N
H
O
NN
NN
12
3
456
7
810
1112
13
1415
1617
18
16 17 18
19 201
3
456
810
1112
13
NN
NN
R R
M
2AcO
+
POCl3 DMF
85∘C 24h
9-Ethyl-9H-carbazole-3-carbaldehyde 9-Ethyl-9H-carbazole-36-dicarbaldehyde
H2N NH2
H2N NH2
H2O OH2
R CH3H
M CoMn
(ZZ)-N N998400-Bis[(9-ethyl-9H-carbazole-3-yl)methylene]propane-13-diamine (L1)
(ZZ)-N N998400-Bis[(9-ethyl-9H-carbazole-3-yl)methylene]-22-dimethylpropane-13-diamine (L2)
Figure 1 Synthesis scheme of the synthesized compounds and the proposed structure for the metal complexes
[119872 + 1]
+ 3081 [119872 minus 204] which arises from the loss often hydrogen and one carbazole units leaving C
21H14N3
1H NMR(400MHz CDCl3) 744(H-1ampH-8 d 119869 = 84)
799 (H-2 dd 119869 = 85amp15) 849 (H-4 d 119869 = 13) 816(H-5 d 119869 = 76) 729 (H-6 dt 119869 = 11amp71) 753 (H-7 dt119869 = 11amp70) 442 (H-14 q 119869 = 72) 148 8H-15 t 119869 = 72)367 (H-16ampH-18 s) 12 (H-19ampH-20 s) 848 (imine s) 13CNMR(400MHz CDCl
3) 1259(C-1) 1259(C-2) 1280(C-3)
12305(C-4) 1208(C-5) 1194(C-6) 1085(C-7) 1087(C-8)1414(C-10) 1272(C-11) 1231(C-12) 1407(C-13) 377(C-14)139(C-15) 582(C-16ampC-18) 373(C-17) 248 (C-19ampC-20)
24 Synthesis of Complex Compounds The ratio of the metalsalts and the ligands was taken as 1 1 (Figure 1) A solutionof the metal salt (1mmol) in 15mL absolute ethanol wasadded into the solution of the ligand L1L2 (1mmol) in 15mLethanol The mixtures were stirred under reflux overnightThe precipitates were filtered washed with distilled water toget rid of the excess salt and dried in vacuum
241 Cobalt(II) Complex of L1 [CoL1(H2O)2]sdot2AcO com-
plex (C33H36CoN4O2) brown coloured yield 72 mp
2055∘C Elemental Analysis found (calculated )
4 Advances in Chemistry
C 6365(6338) H 671(626) N 966(967) Co 1068(1017)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 256(51000)282(11600) 330(87000) 367(75000) 482(30000)560(33000) FT-IR (KBr cmminus1) 3350 3220(O-H) 29722822 2745(Ar-H C-H) 1575(imine) 439(M-N) 537(M-O)ΛM (Ωminus1 cm2molminus1) 801 120583eff BM 435
242 Manganese(II) Complex of L1 [MnL1(H2O)2]sdot2AcO
complex (C33H36MnN4O2) brown coloured yield 64
mp 198∘C Elemental Analysis found (calculated )C 6923(6886) H 621(630) N 1015(973) Mn 1002(954)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 246(86000)291(51000) 375(24000) 640(12000) FT-IR (KBr cmminus1)3342(O-H) 2847 2730(Ar-H C-H) 1589(imine) 481(M-N)604(M-O) ΛM (Ωminus1 cm2molminus1) 287 120583eff BM 585
243 Cobalt(II) Complex of L2 [CoL2(H2O)2]sdot2AcO com-
plex (C35H40CoN4O2) black coloured yield 60 mp
1465∘C Elemental Analysis found (calculated ) C7009(6918) H 692(663) N 957(922) Co 1001(970)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 230(120000)284(61000) 384(43000) 620(10200) FT-IR (KBr cmminus1)3306(O-H) 2919 2812(Ar-H C-H) 1550(imine) 553(M-N)654(M-O) ΛM (Ωminus1 cm2molminus1) 673 120583eff BM 489
244 Manganese(II) Complex of L2 [MnL2(H2O)2]sdot2AcO
complex (C33H40MnN4O2) dark green coloured yield 54
mp 119∘C elemental analysis found (calculated )C 7003(6964) H 714(668) N 967(928) Mn 925(910)UV-V is (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 265(90000)395(71000) 567(14000) FT-IR (KBr cmminus1) 3252(O-H) 29202835(Ar-H C-H) 1540(imine) 490(M-N) 601(M-O) ΛM(Ωminus1 cm2molminus1) 352 120583eff BM 623
25 Preparation of Microorganism Culture The growthinhibitory activity of the synthesized compounds was testedagainst 4 gram negative 4 gram positive bacteria (Kleb-siella pneumoniae FMC 5 Escherichia coli DM and Enter-obacter faecium (clinic isolate) and Enterobacter aerogenesATCC 13048 Bacillus subtilis IMG 22 Bacillus megateriumDSM 32 Staphylococcus aureus ATCC 25923 and Strep-tococcus faecalis) and 3 yeasts (Candida albicans ATCC1023 Candida utilis and Saccharomyces cerevisiae WET136) These microorganisms were provided from Microbiol-ogy Laboratory Culture Collection Department of BiologyKahramanmaras Sutcu Imam University Turkey
Antimicrobial activities of the compoundswere deter-mined using the hollow agarThebacteriawere first incubatedat 37 plusmn 01∘C for 24 h in nutrient broth (Difco) and theyeasts were incubated in Sabouraud dextrose broth (Difco)at 25 plusmn 01∘C for 24 h The cultures of the bacteria and yeastwere injected into the Petri dishes (9 cm) in the amount of01mL (McFarland OD 05 15 times 108 bacteriamL and 15 times106 yeastmL) [38 39 41 42] Then Mueller Hinton agar andSabouraud dextrose agar (sterilized in a flask and cooled to45ndash50∘C)were homogeneously distributed onto the sterilizedPetri dishes in the amount of 25mL Finally 2mg of eachchemical compound dissolved in ethanol was placed inside
the sterilised antibiotic discs The prepared antibiotic discswere then placed in the bacterial medium
Afterwards the plates combined with the discs were leftat 4∘C for 2 h the plates injected with yeast were incubatedat 25 plusmn 01∘C for 24 h and ones injected with bacteria wereincubated at 37 plusmn 01∘C for 24 h After 24 h inhibition zonesappearing around the disks were measured and recorded inmm [41ndash44]
26 Determination of Minimal Inhibitory Concentration(MIC) A broth microdilution broth susceptibility assay wasused as recommended by NCCLS for the determination ofthe MIC of the ligand and the complexes and some referencecomponents [38 41] All tests were performed in MuellerHinton broth (MHB) supplemented with Tween 80 detergent(final concentration of 05 (vv)) with the exception ofthe yeasts (Sabouraud dextrose broth (SDB) + Tween 80)Bacterial strainswere cultured overnight at 37∘C inMHB andthe yeasts were cultured overnight at 30∘C in SDB Geometricdilutions ranging from 200 to 2500120583gmL of the compoundswere prepared including one growth control (MHB + Tween80) and one sterility control (MHB + Tween 80 + testoil) Test tubes were incubated under normal atmosphericconditions at 37∘C for 24 h for bacteria and at 30∘C for48 h for the yeasts The microbial growth was determined byturbidimetric methods
27 Oxidation Procedure A mixture of 110minus3mol cat-alyst 20mL solvent (CH
3CN) and 10mmol cyclohex-
enestyrene was stirred under nitrogen atmosphere in a50mL round-bottom flask equipped with a condenser anda dropping funnel at room temperature for 30min Then20mmol hydrogen peroxide (30 in water) was added(catalyst substrate oxidant ratio is 1 10 20) The resultingmixture was then refluxed for 8 h under nitrogen atmosphereat 90∘C After filtration and washing with solvent the filtratewas concentrated and then subjected to GC analysis Theyields were recorded as the GC yield based on the startingstyrene or cyclohexeneThe identity of the oxidation productswas confirmed by GC-MS A blank reaction was also carriedout without any catalyst for both oxidation reactions
3 Results and Discussion
31 IR and UV Spectra of the Ligands and the ComplexesIR spectrum of 9-ethyl-3-formylcarbazole revealed the char-acteristic weak C-H stretching bands belonging to aromaticrings at 1591 cmminus1 1622 cmminus1 2850 cmminus1 and 2922 cmminus1 Thelatter two bandsmight also be the C-H stretching frequenciesgenerally observed for saturatedmethyl ormethylene groupsThe aromatic aldehyde was observed at 1681 cmminus1 Followingthe imine formation this band was replaced for the iminestretching frequencies at 1638 cmminus1 for L1 and at 1646 cmminus1for L2 In the IR spectra of L1 and L2 the weak bandsbetween 2821 and 2973 cmminus1 belong to weak aromatic andsaturated C-H stretchings The medium strength bands at1598 cmminus1 for L1 and at 1595 cmminus1 for L2 belong to aryl-Hvibrations If we examine the substitution patterns of the
Advances in Chemistry 5
Curr
ent (
120583A
)
Potential (V)
10
0
minus10
minus1 0 1
(a)
Curr
ent (
120583A
)
0
minus10
Potential (V)minus1 0 1
5
minus5
2
(b)
Figure 2 (a) Cyclic voltammogram of L1 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 100mVsminus1 (b) Cyclic
voltammogram of L1-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 500mVsminus1
benzene rings we can say that one metadisubstituted (strongaryl-H vibrations at 806 cmminus1 for L1 and at 809 cmminus1 forL2) and one orthodisubstituted benzene ring (strong aryl-H vibrations at 740 cmminus1 for L1 and at 747 cmminus1 for L2) arepresent in our ligands
Following the coordination the imine frequenciesrecorded for the ligands were red shifted and appearedat around 1575 cmminus1 for L1-Co 1589 cmminus1 for L1-Mn1550 cmminus1 for L2-Co and 1540 cmminus1 for L2-Mn complexesas weak signals All the coordination compounds showedcoordinated water frequencies between 3252 and 3306 cmminus1[45] The M-N stretching vibrations observed between 439and 553 cmminus1 proved that the nitrogens of the imine groupscoordinate with the central metal atoms
The UV spectra of all ligands and the complexeswere taken in ethanol in the range between 200 nm and700 nm For the complex compounds the d-d transitionswere observed between 560 nm and 640 nm and the bandsobserved in the 395ndash367 nm range for these complexes canbe attributed to the charge transfer bands from ligand tometal or from metal to ligand centre [46 47] The 119899-120587lowast and120587-120587lowast transitions of the synthesized ligands and complexeswere observed in 202ndash334 nm region The O-H stretchingfrequencies in watermolecules assisting in coordinationwereseen as broad singlets between 3306 cmminus1 and 3350 cmminus1 [45]All the infrared and uv results are given in the experimentalSections 22ndash24 The magnetic moment values for cobaltcomplexes were recorded as 435 BM and 489 BM whichare characteristic values for tetrahedral cobalt complexes [4647] The manganese(II) complexes gave 585 BM and 623BM values indicating a high spin complex and suggestingtetrahedral geometry [48 49]
32 Electrochemical Properties of the Synthesized CompoundsCyclic voltammogram studies were run inDMF (1 times 10minus3M)ndash01M NBu
4BF4as supporting electrolyte at 293K Electronic
spectra of all the compounds were taken for scan rates 100
250 500 750 and 1000mVsminus1 against an internal ferrocene-ferrocenium standard and we have obtained different oxi-dation and reduction processes for different scan ratesExamination of cv graphics of L1 shows reversible oxidation-reduction processes for the scan rate 100mVsminus1 (Figure 2(a))at 087 V(119864pc) and 088 V(119864pa) (119868pc 119868pa = 1) and for the scanrate 500mVsminus1 at 094V(119864pc) and 104 V(119864pa) (119868pc 119868pa cong 1)The quasireversible processes were observed for 250mVsminus1scan rate at 087V(119864pc) and 10 V(119864pa) and for 750mVsminus1 at09 V(119864pc) and 112 V(119864pa) The rest of the peaks observedfor different scan rates can be said to be irreversible The cvgraphics of cobalt(II) complex of this ligand shows reversibleredox processes for the scan rates 100 500 and 750mVsminus1for example for 500mVsminus1 (Figure 2(b)) the 119868pc 119868pa ratioequals 09 cong 1 (119864pc = 093V and 119864pa = 103V) The otherpeak potentials recorded for this complex gave either quasire-versible or irreversible redoxes The manganese(II) complexof the same ligand gave reversible processes for the scanrates 100 250 and 500mVsminus1 for example for 100mVsminus1 at098V(119864pc) and at 107V(119864pa) 119868pc 119868pa ratio equals around1 The other ligand L2 revealed reversible redoxes for scanrates 250 500 750 and 1000mVsminus1 For example the scanrate 750mVsminus1 (Figure 3(a)) gave cathodic peak potential at098V and anodic peak potential at 099 (119868pc 119868pa=1) Thecobalt complex of this ligand showed reversible redoxes for100 and 250mVsminus1 (Figure 3(b)) scan rates at 113 V(119864pc) and11 V(119864pa) and at 099V(119864pc) and 11 V(119864pa) respectively Themanganese(II) complex of the same ligand gave reversibleprocesses for 100 and 500mVsminus1 The rest of the data can beseen in Table 1 The redox processes for all the complexes canbe defined as the formation of M(II) or M(I) with a simpleone-electron process [24 25] The possible redox process forthe ligands can be shown as in Figure 4
33ThermalAnalysis Thermal gravimetric analysis was usedto explore the thermal stability of these newly synthesizedcompounds and to verify the status of water or solvent
6 Advances in Chemistry
Curr
ent (
120583A
) 0
Potential (V)minus1 0 1
20
minus20
(a)
Potential (V)minus1 0 1
Curr
ent (
120583A
) 0
20
minus20
(b)
Figure 3 (a) Cyclic voltammogram of L2 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 750mVsminus1 (b) Cyclic
voltammogram of L2-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 250mVsminus1
Table 1 Electrochemical data of the title compounds
Compound Scan rate (mVs) 119864pc (119864pa) (V) 119864
12(V) Δ119864
119901(V)
L1
100 087 minus118 (minus057 088) 088 001250 087 minus006 minus124 (minus048 100) mdash 013500 094 minus008 minus132 (minus042 104) mdash 015750 090 minus012 minus140 (minus038 112) mdash 0221000 090 minus014 minus142 (minus035 114) mdash 024
[Co(L1)(H2O)2]2AcO
100 072 minus114 (minus058 080) mdash 012250 076 minus128 (minus050 093) mdash 017500 093 minus140 (minus046 103) mdash 016750 097 minus147 (minus046 107) mdash 0211000 087 minus154 (minus042 117) mdash 030
[Mn(L1)(H2O)2]2AcO
100 098 minus111 (minus052 107) mdash 009250 098 minus113 (minus054 102) mdash 004500 097 minus128 (minus040 108) mdash 013750 096 minus141 (minus033 126) mdash 0301000 097 minus147 (minus026 122) mdash 025
L2
100 009 minus090 (minus056 minus001 082) mdash minus010250 091 003 minus101 (minus053 093) 092 002500 094 minus002 minus109 (minus050 095) 095 001750 098 minus112 (minus044 099) 099 0011000 096 minus131 (minus035 099) 098 003
[Co(L2)(H2O)2]2AcO
100 113 minus003 minus091 (minus053 014 125) mdash 017250 099 minus007 minus096 (minus047 020 110) 072 012500 096 minus008 minus102 (minus050 113) 076 017750 095 minus119 (minus041 110) mdash 0151000 097 minus142 (minus027 110) mdash 013
[Mn(L2)(H2O)2]2AcO
100 110 minus005 minus092 (minus054 119) mdash 020250 096 001 minus100 (minus049 118) 075 022500 097 013 minus112 (minus042 107) mdash 012750 096 minus122 (minus030 111) mdash 0151000 093 minus143 (minus024 115) mdash 022
Advances in Chemistry 7
NN
R R
HNNH ArArArAr
R R
2H++ 2eminus
minus2H+minus 2eminus
Figure 4 Reversible reduction oxidation processes of the title compounds L1 and L2 in DMF (110minus3M) solution
Wei
ght (
)
Temperature (∘C)
100
90
80
70
60
50
40
30
20
10
100 200 300 400 500 600 700 800 900
(a)W
eigh
t (
)
100
80
60
40
20
5
Temperature (∘C)100 200 300 400 500 600 700 800 900
110
(b)
Figure 5 (a) TGplot of L1 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L2-Mn recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Wei
ght (
)
100
90
80
70
60
50
40
30
20
10
Temperature (∘C)100 200 300 400 500 600 700 800 900
(a)
Wei
ght (
)
100
90
80
70
60
50
40
30
20
Temperature (∘C)100 200 300 400 500 600 700 800 900
(b)
Figure 6 (a) TGplot of L2 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L1-Co recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
molecules whether to be inside or outside of the coordinationsphere of the complex compounds [26 50] The resultsof thermal analysis of the title compounds are in goodagreement with the theoretical formulae as suggested fromspectral analyses The thermogram of L1 (Figure 5(a)) showsdecomposition starting around 220∘C with the loss of twoethyl groups adjacent to nitrogen in the carbazole units with12(Calc1197) The biggest loss was observed betweenthe temperatures 340∘C and 520∘C with a percentage of6823(Calc68) which is assigned to the two carbazoleunits The residual part was found as 1987(Calc20)One could also say that the 851(Calc867) of the resid-ual part may belong to the propyl unit which plays abridge role between the two imine groups TG plot of[CoL1(H
2O)2]2AcO complex gives somewhat distorted three
decomposition steps (Figure 6(b)) the first of which is
observed between the temperature ranges 150∘C and 220∘Cwith a 92(Calc10) loss belonging to the two ethyl groupson the nitrogen atoms The second decomposition belongsto two carbazole units with a loss of 5822(Calc5735)The third decomposition step however was assigned asthe loss of C
5H8N2 The residual part gave percentages for
metallic Co and the two water molecules Mn(II) complexof this ligand starts to decompose at around 90∘C Betweenthe temperatures 200∘C and 430∘C our complex shows thehighest percentage loss with 5711(Calc5775) belongingto the carbazole groups Our second ligand L2 decomposesbetween the temperatures 300∘Cand 500∘Cwith a total loss of7632(Calc7617) corresponding to the two carbazoles inour structures (Figure 6(a)) TG graphics of Mn(II) complexof L2 (Figure 5(b)) shows three decomposition stepsThe firstone at 110∘C corresponds to the loss of ethyl groups on the
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
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Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
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Journal of
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Quantum Chemistry
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Organic Chemistry International
ElectrochemistryInternational Journal of
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
2 Advances in Chemistry
thermal electrochemical antimicrobial features and theireffect as catalysts in the oxidation reactions of cyclohexeneand styrene
2 Experiment
21 Materials and Instrumentation 9-Ethylcarbazole phos-phorus(V) oxychloride 13-diaminopropane and 22-dimethyl-13-diaminopropane all the solvents used andacetate salts of copper(II) andmanganese(II) were purchasedfrom Sigma Aldrich Nuclear magnetic resonance spectraof the synthesized ligands were recorded on a Bruker AV400MHz spectrometer in the solvent CDCl
3 Infrared
spectra were obtained using KBr discs on a Shimadzu 8300FTIR spectrophotometer in the region of 400ndash4000 cmminus1Ultraviolet spectra were run in ethanol on a SchimadzuUV-160A spectrophotometer Magnetic measurements werecarried out by the Gouy method using Hg[Co(SCN)
4] as
a calibrant Molar conductances of the ligands and theirtransition metal complexes were determined in MeOH(sim10minus3) at room temperature using a Jenway Model 4070conductivity meter Mass spectra of the ligand were recordedon a LCMS APCI Agilent 1100MSD spectrophotometerTheoxidation products were analyzed with a gas chromatograph(Shimadzu GC-14B) equipped with a SAB-5 capillarycolumn and a flame ionization detector Elemental analyseswere performed on a LECO CHNS 932 elemental analyzerand the metal analyses were carried out on an Ati Unicam929 Model AA spectrometer in solutions prepared bydecomposing the compounds in aqua regia and subsequentlydigesting them in concentrated HCl Thermal analysesof synthesized ligands and their metal complexes werecarried out on a Perkin-Elmer Thermogravimetric AnalyzerTGDTA 6300 instrument under nitrogen atmospherebetween the temperature ranges 30∘C and 988∘C at a heatingrate of 10∘Cmin Cyclic voltammetry was performed usingIviumStat electrochemical workstation equipped with a lowcurrent module (BAS PA-1) recorder
22 Synthesis of 9-Ethyl-9H-carbazole-3-carbaldehyde For-mulation of 9-ethylcarbazole was done by using Vilsmeierformulating agentsDMF andPOCl
3 Inside a fume cupboard
DMF (32mL 04mol) was put into a 250mL round-bottomflask placed in an ice bath Over DMF at 0∘C 32mL (032mol)POCl
3was added dropwise through a dropping funnel
Resulting solution was stirred at room temperature for 2hours To the stirring mixture 9-ethyl-9H-carbazole (8 g004mol) dissolved in 32mL DMF was slowly added Thereaction mixture was heated at 80∘C and left stirring for 24hours The resulting dark coloured mixture was poured intoslurry of crushed ice and water (250mL) The precipitatewas washed with water and extracted by CHCl
3and then
washed with n-hexane The dirty yellow precipitate wassubjected to flash column chromatography with the eluent ofethyl acetatehexane (1 10) Vilsmeier reaction always givesboth mono- and dialdehyde of the formulated carbazole[39 40] The monoaldehyde was the first product eluatedas yellowish-white crystals The dialdehyde obtained was
white solid TLC chromatography elemental analysis andspectral data confirm the purity and structure of synthesizedmono- and dialdehyde products Monoaldehyde 9-ethyl-9H-carbazole-3-carbaldehyde yield 40 mp 85ndash87∘CUV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 202(50000)210(80000) 226(30000) 264(36000) 284(95000) FT-IR(KBr cmminus1) 1591(w) 1622(w) 2850(w) 2922(w)(Ar-Hand C-H) 1681(s)(CHO) 1H NMR(400MHz CDCl
3)
101(CHO) 86 (H-4 d 119869 = 13) 816 (H-5 brd 119869 = 78) 802(H-2 dd 119869 = 85amp158) 746 (H-1ampH-8 d 119869 = 84) 756 (H-7dt 119869 = 82amp12) 735 (H-6 dt 119869 = 80amp103) 439 (2H-14 q119869 = 72) 147 (3H-15 t 119869 = 72) 13CNMR(400MHzCDCl
3)
1918(CHO) 1272(C-1) 1268(C-2) 1285(C-3) 12401(C-4)1208(C-5) 1203(C-6) 1087(C-7) 1092(C-8) 1435(C-10)1231(C-11) 1230(C-12) 1407(C-13) 379(C-14) 139(C-15)Mass spectrum (LCMS APCI) mz 2237 [M]+
23 Synthesis of the Ligands (ZZ)-NN1015840-Bis[(9-ethyl-9H-carbazol-3-yl)methylene]propane-13-diamine (L1) and (ZZ)-NN1015840-Bis[(9-ethyl-9H-carbazol-3-yl)methylene]-22-dimethyl-propane-13-diamine (L2) Inside a 100mL round-bottomflask 045 g (2mmol) 9-ethyl-9H-carbazole-3-carbaldehydewas put and dissolved in enough amount of ethanol Overthis 01 g (1mmol) diamine was added dropwise The result-ing solution was heated under reflux for four hours andleft overnight The white precipitate was recrystallized fromethanol (Figure 1)
231 (ZZ)-NN1015840 -Bis[(9-ethyl-9H-carbazole-3-yl)methylene]-propane-13-diamine (L1) Yield 80 mp 167∘C elementalanalysis found (calculated ) C 8234(8178) H 680(666)N 1201(1156) UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1)216(175000) 250(105000) 266(120000) 296(210000)310(161000) FT-IR (KBr cmminus1) 2843(w) 2920(w)2971(w) 1598(w)(Ar-H and C-H) 806(s) 740(s)(Ar-H)1637(s)(imine) Mass spectrum (LCMS APCI) mz 4852[119872 + 1]
+ 2801 [119872 minus 20453] which arises from the lossof ten hydrogen and one carbazole units leaving C
19H10N3
1H NMR(400MHz CDCl3) 744 (H-1ampH-8 d 119869 = 85)
792 (H-2 dd 119869 = 85amp15) 849 (H-4 d 119869 = 14) 815(H-5 d 119869 = 76) 728 (H-6 dt 119869 = 12amp76) 751 (H-7 dt119869 = 12amp71) 441 (H-14 q 119869 = 72) 147 (H-15 t 119869 = 72)384 (H-16ampH-18 q 119869 = 7) 226 (H-17 m 119869 = 7) 85 (imines) 13C NMR(400MHz CDCl
3) 12603(C-1) 1259(C-2)
1277(C-3) 1231(C-4) 1207(C-5) 1194(C-6) 1085(C-7)1087(C-8) 1415(C-10) 1272(C-11) 1240(C-12) 1405(C-13) 377(C-14) 138(C-15) 595(C-16ampC-18) 323(C-17)16206(imine)
232 (ZZ)-NN1015840-Bis[(9-ethyl-9H-carbazol-3-yl)methylene]-22-dimethylpropane-13-diamine (L2) Yield 75 mp115∘C elemental analysis found (calculated ) C 8211(8199) H 7530(708) N 1101(1093) UV-Vis (ethanol) (120582maxnm) (120576 Mminus1 cmminus1) 268(115000) 300(78000) 306(61000)334(99000) FT-IR (KBr cmminus1) 2973(w) 2949(w) 2867(w)2821(w) 1595(w) (Ar-H and C-H) 809(s) 747(s)(Ar-H)1646(s)(imine) Mass spectrum (LCMS APCI) mz 5143
Advances in Chemistry 3
1
23
456
7
8 10
1112
13
1415
N N
H
O
N
H
O
H
O
N
H
O
NN
NN
N
H
O
NN
NN
12
3
456
7
810
1112
13
1415
1617
18
16 17 18
19 201
3
456
810
1112
13
NN
NN
R R
M
2AcO
+
POCl3 DMF
85∘C 24h
9-Ethyl-9H-carbazole-3-carbaldehyde 9-Ethyl-9H-carbazole-36-dicarbaldehyde
H2N NH2
H2N NH2
H2O OH2
R CH3H
M CoMn
(ZZ)-N N998400-Bis[(9-ethyl-9H-carbazole-3-yl)methylene]propane-13-diamine (L1)
(ZZ)-N N998400-Bis[(9-ethyl-9H-carbazole-3-yl)methylene]-22-dimethylpropane-13-diamine (L2)
Figure 1 Synthesis scheme of the synthesized compounds and the proposed structure for the metal complexes
[119872 + 1]
+ 3081 [119872 minus 204] which arises from the loss often hydrogen and one carbazole units leaving C
21H14N3
1H NMR(400MHz CDCl3) 744(H-1ampH-8 d 119869 = 84)
799 (H-2 dd 119869 = 85amp15) 849 (H-4 d 119869 = 13) 816(H-5 d 119869 = 76) 729 (H-6 dt 119869 = 11amp71) 753 (H-7 dt119869 = 11amp70) 442 (H-14 q 119869 = 72) 148 8H-15 t 119869 = 72)367 (H-16ampH-18 s) 12 (H-19ampH-20 s) 848 (imine s) 13CNMR(400MHz CDCl
3) 1259(C-1) 1259(C-2) 1280(C-3)
12305(C-4) 1208(C-5) 1194(C-6) 1085(C-7) 1087(C-8)1414(C-10) 1272(C-11) 1231(C-12) 1407(C-13) 377(C-14)139(C-15) 582(C-16ampC-18) 373(C-17) 248 (C-19ampC-20)
24 Synthesis of Complex Compounds The ratio of the metalsalts and the ligands was taken as 1 1 (Figure 1) A solutionof the metal salt (1mmol) in 15mL absolute ethanol wasadded into the solution of the ligand L1L2 (1mmol) in 15mLethanol The mixtures were stirred under reflux overnightThe precipitates were filtered washed with distilled water toget rid of the excess salt and dried in vacuum
241 Cobalt(II) Complex of L1 [CoL1(H2O)2]sdot2AcO com-
plex (C33H36CoN4O2) brown coloured yield 72 mp
2055∘C Elemental Analysis found (calculated )
4 Advances in Chemistry
C 6365(6338) H 671(626) N 966(967) Co 1068(1017)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 256(51000)282(11600) 330(87000) 367(75000) 482(30000)560(33000) FT-IR (KBr cmminus1) 3350 3220(O-H) 29722822 2745(Ar-H C-H) 1575(imine) 439(M-N) 537(M-O)ΛM (Ωminus1 cm2molminus1) 801 120583eff BM 435
242 Manganese(II) Complex of L1 [MnL1(H2O)2]sdot2AcO
complex (C33H36MnN4O2) brown coloured yield 64
mp 198∘C Elemental Analysis found (calculated )C 6923(6886) H 621(630) N 1015(973) Mn 1002(954)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 246(86000)291(51000) 375(24000) 640(12000) FT-IR (KBr cmminus1)3342(O-H) 2847 2730(Ar-H C-H) 1589(imine) 481(M-N)604(M-O) ΛM (Ωminus1 cm2molminus1) 287 120583eff BM 585
243 Cobalt(II) Complex of L2 [CoL2(H2O)2]sdot2AcO com-
plex (C35H40CoN4O2) black coloured yield 60 mp
1465∘C Elemental Analysis found (calculated ) C7009(6918) H 692(663) N 957(922) Co 1001(970)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 230(120000)284(61000) 384(43000) 620(10200) FT-IR (KBr cmminus1)3306(O-H) 2919 2812(Ar-H C-H) 1550(imine) 553(M-N)654(M-O) ΛM (Ωminus1 cm2molminus1) 673 120583eff BM 489
244 Manganese(II) Complex of L2 [MnL2(H2O)2]sdot2AcO
complex (C33H40MnN4O2) dark green coloured yield 54
mp 119∘C elemental analysis found (calculated )C 7003(6964) H 714(668) N 967(928) Mn 925(910)UV-V is (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 265(90000)395(71000) 567(14000) FT-IR (KBr cmminus1) 3252(O-H) 29202835(Ar-H C-H) 1540(imine) 490(M-N) 601(M-O) ΛM(Ωminus1 cm2molminus1) 352 120583eff BM 623
25 Preparation of Microorganism Culture The growthinhibitory activity of the synthesized compounds was testedagainst 4 gram negative 4 gram positive bacteria (Kleb-siella pneumoniae FMC 5 Escherichia coli DM and Enter-obacter faecium (clinic isolate) and Enterobacter aerogenesATCC 13048 Bacillus subtilis IMG 22 Bacillus megateriumDSM 32 Staphylococcus aureus ATCC 25923 and Strep-tococcus faecalis) and 3 yeasts (Candida albicans ATCC1023 Candida utilis and Saccharomyces cerevisiae WET136) These microorganisms were provided from Microbiol-ogy Laboratory Culture Collection Department of BiologyKahramanmaras Sutcu Imam University Turkey
Antimicrobial activities of the compoundswere deter-mined using the hollow agarThebacteriawere first incubatedat 37 plusmn 01∘C for 24 h in nutrient broth (Difco) and theyeasts were incubated in Sabouraud dextrose broth (Difco)at 25 plusmn 01∘C for 24 h The cultures of the bacteria and yeastwere injected into the Petri dishes (9 cm) in the amount of01mL (McFarland OD 05 15 times 108 bacteriamL and 15 times106 yeastmL) [38 39 41 42] Then Mueller Hinton agar andSabouraud dextrose agar (sterilized in a flask and cooled to45ndash50∘C)were homogeneously distributed onto the sterilizedPetri dishes in the amount of 25mL Finally 2mg of eachchemical compound dissolved in ethanol was placed inside
the sterilised antibiotic discs The prepared antibiotic discswere then placed in the bacterial medium
Afterwards the plates combined with the discs were leftat 4∘C for 2 h the plates injected with yeast were incubatedat 25 plusmn 01∘C for 24 h and ones injected with bacteria wereincubated at 37 plusmn 01∘C for 24 h After 24 h inhibition zonesappearing around the disks were measured and recorded inmm [41ndash44]
26 Determination of Minimal Inhibitory Concentration(MIC) A broth microdilution broth susceptibility assay wasused as recommended by NCCLS for the determination ofthe MIC of the ligand and the complexes and some referencecomponents [38 41] All tests were performed in MuellerHinton broth (MHB) supplemented with Tween 80 detergent(final concentration of 05 (vv)) with the exception ofthe yeasts (Sabouraud dextrose broth (SDB) + Tween 80)Bacterial strainswere cultured overnight at 37∘C inMHB andthe yeasts were cultured overnight at 30∘C in SDB Geometricdilutions ranging from 200 to 2500120583gmL of the compoundswere prepared including one growth control (MHB + Tween80) and one sterility control (MHB + Tween 80 + testoil) Test tubes were incubated under normal atmosphericconditions at 37∘C for 24 h for bacteria and at 30∘C for48 h for the yeasts The microbial growth was determined byturbidimetric methods
27 Oxidation Procedure A mixture of 110minus3mol cat-alyst 20mL solvent (CH
3CN) and 10mmol cyclohex-
enestyrene was stirred under nitrogen atmosphere in a50mL round-bottom flask equipped with a condenser anda dropping funnel at room temperature for 30min Then20mmol hydrogen peroxide (30 in water) was added(catalyst substrate oxidant ratio is 1 10 20) The resultingmixture was then refluxed for 8 h under nitrogen atmosphereat 90∘C After filtration and washing with solvent the filtratewas concentrated and then subjected to GC analysis Theyields were recorded as the GC yield based on the startingstyrene or cyclohexeneThe identity of the oxidation productswas confirmed by GC-MS A blank reaction was also carriedout without any catalyst for both oxidation reactions
3 Results and Discussion
31 IR and UV Spectra of the Ligands and the ComplexesIR spectrum of 9-ethyl-3-formylcarbazole revealed the char-acteristic weak C-H stretching bands belonging to aromaticrings at 1591 cmminus1 1622 cmminus1 2850 cmminus1 and 2922 cmminus1 Thelatter two bandsmight also be the C-H stretching frequenciesgenerally observed for saturatedmethyl ormethylene groupsThe aromatic aldehyde was observed at 1681 cmminus1 Followingthe imine formation this band was replaced for the iminestretching frequencies at 1638 cmminus1 for L1 and at 1646 cmminus1for L2 In the IR spectra of L1 and L2 the weak bandsbetween 2821 and 2973 cmminus1 belong to weak aromatic andsaturated C-H stretchings The medium strength bands at1598 cmminus1 for L1 and at 1595 cmminus1 for L2 belong to aryl-Hvibrations If we examine the substitution patterns of the
Advances in Chemistry 5
Curr
ent (
120583A
)
Potential (V)
10
0
minus10
minus1 0 1
(a)
Curr
ent (
120583A
)
0
minus10
Potential (V)minus1 0 1
5
minus5
2
(b)
Figure 2 (a) Cyclic voltammogram of L1 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 100mVsminus1 (b) Cyclic
voltammogram of L1-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 500mVsminus1
benzene rings we can say that one metadisubstituted (strongaryl-H vibrations at 806 cmminus1 for L1 and at 809 cmminus1 forL2) and one orthodisubstituted benzene ring (strong aryl-H vibrations at 740 cmminus1 for L1 and at 747 cmminus1 for L2) arepresent in our ligands
Following the coordination the imine frequenciesrecorded for the ligands were red shifted and appearedat around 1575 cmminus1 for L1-Co 1589 cmminus1 for L1-Mn1550 cmminus1 for L2-Co and 1540 cmminus1 for L2-Mn complexesas weak signals All the coordination compounds showedcoordinated water frequencies between 3252 and 3306 cmminus1[45] The M-N stretching vibrations observed between 439and 553 cmminus1 proved that the nitrogens of the imine groupscoordinate with the central metal atoms
The UV spectra of all ligands and the complexeswere taken in ethanol in the range between 200 nm and700 nm For the complex compounds the d-d transitionswere observed between 560 nm and 640 nm and the bandsobserved in the 395ndash367 nm range for these complexes canbe attributed to the charge transfer bands from ligand tometal or from metal to ligand centre [46 47] The 119899-120587lowast and120587-120587lowast transitions of the synthesized ligands and complexeswere observed in 202ndash334 nm region The O-H stretchingfrequencies in watermolecules assisting in coordinationwereseen as broad singlets between 3306 cmminus1 and 3350 cmminus1 [45]All the infrared and uv results are given in the experimentalSections 22ndash24 The magnetic moment values for cobaltcomplexes were recorded as 435 BM and 489 BM whichare characteristic values for tetrahedral cobalt complexes [4647] The manganese(II) complexes gave 585 BM and 623BM values indicating a high spin complex and suggestingtetrahedral geometry [48 49]
32 Electrochemical Properties of the Synthesized CompoundsCyclic voltammogram studies were run inDMF (1 times 10minus3M)ndash01M NBu
4BF4as supporting electrolyte at 293K Electronic
spectra of all the compounds were taken for scan rates 100
250 500 750 and 1000mVsminus1 against an internal ferrocene-ferrocenium standard and we have obtained different oxi-dation and reduction processes for different scan ratesExamination of cv graphics of L1 shows reversible oxidation-reduction processes for the scan rate 100mVsminus1 (Figure 2(a))at 087 V(119864pc) and 088 V(119864pa) (119868pc 119868pa = 1) and for the scanrate 500mVsminus1 at 094V(119864pc) and 104 V(119864pa) (119868pc 119868pa cong 1)The quasireversible processes were observed for 250mVsminus1scan rate at 087V(119864pc) and 10 V(119864pa) and for 750mVsminus1 at09 V(119864pc) and 112 V(119864pa) The rest of the peaks observedfor different scan rates can be said to be irreversible The cvgraphics of cobalt(II) complex of this ligand shows reversibleredox processes for the scan rates 100 500 and 750mVsminus1for example for 500mVsminus1 (Figure 2(b)) the 119868pc 119868pa ratioequals 09 cong 1 (119864pc = 093V and 119864pa = 103V) The otherpeak potentials recorded for this complex gave either quasire-versible or irreversible redoxes The manganese(II) complexof the same ligand gave reversible processes for the scanrates 100 250 and 500mVsminus1 for example for 100mVsminus1 at098V(119864pc) and at 107V(119864pa) 119868pc 119868pa ratio equals around1 The other ligand L2 revealed reversible redoxes for scanrates 250 500 750 and 1000mVsminus1 For example the scanrate 750mVsminus1 (Figure 3(a)) gave cathodic peak potential at098V and anodic peak potential at 099 (119868pc 119868pa=1) Thecobalt complex of this ligand showed reversible redoxes for100 and 250mVsminus1 (Figure 3(b)) scan rates at 113 V(119864pc) and11 V(119864pa) and at 099V(119864pc) and 11 V(119864pa) respectively Themanganese(II) complex of the same ligand gave reversibleprocesses for 100 and 500mVsminus1 The rest of the data can beseen in Table 1 The redox processes for all the complexes canbe defined as the formation of M(II) or M(I) with a simpleone-electron process [24 25] The possible redox process forthe ligands can be shown as in Figure 4
33ThermalAnalysis Thermal gravimetric analysis was usedto explore the thermal stability of these newly synthesizedcompounds and to verify the status of water or solvent
6 Advances in Chemistry
Curr
ent (
120583A
) 0
Potential (V)minus1 0 1
20
minus20
(a)
Potential (V)minus1 0 1
Curr
ent (
120583A
) 0
20
minus20
(b)
Figure 3 (a) Cyclic voltammogram of L2 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 750mVsminus1 (b) Cyclic
voltammogram of L2-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 250mVsminus1
Table 1 Electrochemical data of the title compounds
Compound Scan rate (mVs) 119864pc (119864pa) (V) 119864
12(V) Δ119864
119901(V)
L1
100 087 minus118 (minus057 088) 088 001250 087 minus006 minus124 (minus048 100) mdash 013500 094 minus008 minus132 (minus042 104) mdash 015750 090 minus012 minus140 (minus038 112) mdash 0221000 090 minus014 minus142 (minus035 114) mdash 024
[Co(L1)(H2O)2]2AcO
100 072 minus114 (minus058 080) mdash 012250 076 minus128 (minus050 093) mdash 017500 093 minus140 (minus046 103) mdash 016750 097 minus147 (minus046 107) mdash 0211000 087 minus154 (minus042 117) mdash 030
[Mn(L1)(H2O)2]2AcO
100 098 minus111 (minus052 107) mdash 009250 098 minus113 (minus054 102) mdash 004500 097 minus128 (minus040 108) mdash 013750 096 minus141 (minus033 126) mdash 0301000 097 minus147 (minus026 122) mdash 025
L2
100 009 minus090 (minus056 minus001 082) mdash minus010250 091 003 minus101 (minus053 093) 092 002500 094 minus002 minus109 (minus050 095) 095 001750 098 minus112 (minus044 099) 099 0011000 096 minus131 (minus035 099) 098 003
[Co(L2)(H2O)2]2AcO
100 113 minus003 minus091 (minus053 014 125) mdash 017250 099 minus007 minus096 (minus047 020 110) 072 012500 096 minus008 minus102 (minus050 113) 076 017750 095 minus119 (minus041 110) mdash 0151000 097 minus142 (minus027 110) mdash 013
[Mn(L2)(H2O)2]2AcO
100 110 minus005 minus092 (minus054 119) mdash 020250 096 001 minus100 (minus049 118) 075 022500 097 013 minus112 (minus042 107) mdash 012750 096 minus122 (minus030 111) mdash 0151000 093 minus143 (minus024 115) mdash 022
Advances in Chemistry 7
NN
R R
HNNH ArArArAr
R R
2H++ 2eminus
minus2H+minus 2eminus
Figure 4 Reversible reduction oxidation processes of the title compounds L1 and L2 in DMF (110minus3M) solution
Wei
ght (
)
Temperature (∘C)
100
90
80
70
60
50
40
30
20
10
100 200 300 400 500 600 700 800 900
(a)W
eigh
t (
)
100
80
60
40
20
5
Temperature (∘C)100 200 300 400 500 600 700 800 900
110
(b)
Figure 5 (a) TGplot of L1 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L2-Mn recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Wei
ght (
)
100
90
80
70
60
50
40
30
20
10
Temperature (∘C)100 200 300 400 500 600 700 800 900
(a)
Wei
ght (
)
100
90
80
70
60
50
40
30
20
Temperature (∘C)100 200 300 400 500 600 700 800 900
(b)
Figure 6 (a) TGplot of L2 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L1-Co recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
molecules whether to be inside or outside of the coordinationsphere of the complex compounds [26 50] The resultsof thermal analysis of the title compounds are in goodagreement with the theoretical formulae as suggested fromspectral analyses The thermogram of L1 (Figure 5(a)) showsdecomposition starting around 220∘C with the loss of twoethyl groups adjacent to nitrogen in the carbazole units with12(Calc1197) The biggest loss was observed betweenthe temperatures 340∘C and 520∘C with a percentage of6823(Calc68) which is assigned to the two carbazoleunits The residual part was found as 1987(Calc20)One could also say that the 851(Calc867) of the resid-ual part may belong to the propyl unit which plays abridge role between the two imine groups TG plot of[CoL1(H
2O)2]2AcO complex gives somewhat distorted three
decomposition steps (Figure 6(b)) the first of which is
observed between the temperature ranges 150∘C and 220∘Cwith a 92(Calc10) loss belonging to the two ethyl groupson the nitrogen atoms The second decomposition belongsto two carbazole units with a loss of 5822(Calc5735)The third decomposition step however was assigned asthe loss of C
5H8N2 The residual part gave percentages for
metallic Co and the two water molecules Mn(II) complexof this ligand starts to decompose at around 90∘C Betweenthe temperatures 200∘C and 430∘C our complex shows thehighest percentage loss with 5711(Calc5775) belongingto the carbazole groups Our second ligand L2 decomposesbetween the temperatures 300∘Cand 500∘Cwith a total loss of7632(Calc7617) corresponding to the two carbazoles inour structures (Figure 6(a)) TG graphics of Mn(II) complexof L2 (Figure 5(b)) shows three decomposition stepsThe firstone at 110∘C corresponds to the loss of ethyl groups on the
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Advances in Chemistry 3
1
23
456
7
8 10
1112
13
1415
N N
H
O
N
H
O
H
O
N
H
O
NN
NN
N
H
O
NN
NN
12
3
456
7
810
1112
13
1415
1617
18
16 17 18
19 201
3
456
810
1112
13
NN
NN
R R
M
2AcO
+
POCl3 DMF
85∘C 24h
9-Ethyl-9H-carbazole-3-carbaldehyde 9-Ethyl-9H-carbazole-36-dicarbaldehyde
H2N NH2
H2N NH2
H2O OH2
R CH3H
M CoMn
(ZZ)-N N998400-Bis[(9-ethyl-9H-carbazole-3-yl)methylene]propane-13-diamine (L1)
(ZZ)-N N998400-Bis[(9-ethyl-9H-carbazole-3-yl)methylene]-22-dimethylpropane-13-diamine (L2)
Figure 1 Synthesis scheme of the synthesized compounds and the proposed structure for the metal complexes
[119872 + 1]
+ 3081 [119872 minus 204] which arises from the loss often hydrogen and one carbazole units leaving C
21H14N3
1H NMR(400MHz CDCl3) 744(H-1ampH-8 d 119869 = 84)
799 (H-2 dd 119869 = 85amp15) 849 (H-4 d 119869 = 13) 816(H-5 d 119869 = 76) 729 (H-6 dt 119869 = 11amp71) 753 (H-7 dt119869 = 11amp70) 442 (H-14 q 119869 = 72) 148 8H-15 t 119869 = 72)367 (H-16ampH-18 s) 12 (H-19ampH-20 s) 848 (imine s) 13CNMR(400MHz CDCl
3) 1259(C-1) 1259(C-2) 1280(C-3)
12305(C-4) 1208(C-5) 1194(C-6) 1085(C-7) 1087(C-8)1414(C-10) 1272(C-11) 1231(C-12) 1407(C-13) 377(C-14)139(C-15) 582(C-16ampC-18) 373(C-17) 248 (C-19ampC-20)
24 Synthesis of Complex Compounds The ratio of the metalsalts and the ligands was taken as 1 1 (Figure 1) A solutionof the metal salt (1mmol) in 15mL absolute ethanol wasadded into the solution of the ligand L1L2 (1mmol) in 15mLethanol The mixtures were stirred under reflux overnightThe precipitates were filtered washed with distilled water toget rid of the excess salt and dried in vacuum
241 Cobalt(II) Complex of L1 [CoL1(H2O)2]sdot2AcO com-
plex (C33H36CoN4O2) brown coloured yield 72 mp
2055∘C Elemental Analysis found (calculated )
4 Advances in Chemistry
C 6365(6338) H 671(626) N 966(967) Co 1068(1017)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 256(51000)282(11600) 330(87000) 367(75000) 482(30000)560(33000) FT-IR (KBr cmminus1) 3350 3220(O-H) 29722822 2745(Ar-H C-H) 1575(imine) 439(M-N) 537(M-O)ΛM (Ωminus1 cm2molminus1) 801 120583eff BM 435
242 Manganese(II) Complex of L1 [MnL1(H2O)2]sdot2AcO
complex (C33H36MnN4O2) brown coloured yield 64
mp 198∘C Elemental Analysis found (calculated )C 6923(6886) H 621(630) N 1015(973) Mn 1002(954)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 246(86000)291(51000) 375(24000) 640(12000) FT-IR (KBr cmminus1)3342(O-H) 2847 2730(Ar-H C-H) 1589(imine) 481(M-N)604(M-O) ΛM (Ωminus1 cm2molminus1) 287 120583eff BM 585
243 Cobalt(II) Complex of L2 [CoL2(H2O)2]sdot2AcO com-
plex (C35H40CoN4O2) black coloured yield 60 mp
1465∘C Elemental Analysis found (calculated ) C7009(6918) H 692(663) N 957(922) Co 1001(970)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 230(120000)284(61000) 384(43000) 620(10200) FT-IR (KBr cmminus1)3306(O-H) 2919 2812(Ar-H C-H) 1550(imine) 553(M-N)654(M-O) ΛM (Ωminus1 cm2molminus1) 673 120583eff BM 489
244 Manganese(II) Complex of L2 [MnL2(H2O)2]sdot2AcO
complex (C33H40MnN4O2) dark green coloured yield 54
mp 119∘C elemental analysis found (calculated )C 7003(6964) H 714(668) N 967(928) Mn 925(910)UV-V is (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 265(90000)395(71000) 567(14000) FT-IR (KBr cmminus1) 3252(O-H) 29202835(Ar-H C-H) 1540(imine) 490(M-N) 601(M-O) ΛM(Ωminus1 cm2molminus1) 352 120583eff BM 623
25 Preparation of Microorganism Culture The growthinhibitory activity of the synthesized compounds was testedagainst 4 gram negative 4 gram positive bacteria (Kleb-siella pneumoniae FMC 5 Escherichia coli DM and Enter-obacter faecium (clinic isolate) and Enterobacter aerogenesATCC 13048 Bacillus subtilis IMG 22 Bacillus megateriumDSM 32 Staphylococcus aureus ATCC 25923 and Strep-tococcus faecalis) and 3 yeasts (Candida albicans ATCC1023 Candida utilis and Saccharomyces cerevisiae WET136) These microorganisms were provided from Microbiol-ogy Laboratory Culture Collection Department of BiologyKahramanmaras Sutcu Imam University Turkey
Antimicrobial activities of the compoundswere deter-mined using the hollow agarThebacteriawere first incubatedat 37 plusmn 01∘C for 24 h in nutrient broth (Difco) and theyeasts were incubated in Sabouraud dextrose broth (Difco)at 25 plusmn 01∘C for 24 h The cultures of the bacteria and yeastwere injected into the Petri dishes (9 cm) in the amount of01mL (McFarland OD 05 15 times 108 bacteriamL and 15 times106 yeastmL) [38 39 41 42] Then Mueller Hinton agar andSabouraud dextrose agar (sterilized in a flask and cooled to45ndash50∘C)were homogeneously distributed onto the sterilizedPetri dishes in the amount of 25mL Finally 2mg of eachchemical compound dissolved in ethanol was placed inside
the sterilised antibiotic discs The prepared antibiotic discswere then placed in the bacterial medium
Afterwards the plates combined with the discs were leftat 4∘C for 2 h the plates injected with yeast were incubatedat 25 plusmn 01∘C for 24 h and ones injected with bacteria wereincubated at 37 plusmn 01∘C for 24 h After 24 h inhibition zonesappearing around the disks were measured and recorded inmm [41ndash44]
26 Determination of Minimal Inhibitory Concentration(MIC) A broth microdilution broth susceptibility assay wasused as recommended by NCCLS for the determination ofthe MIC of the ligand and the complexes and some referencecomponents [38 41] All tests were performed in MuellerHinton broth (MHB) supplemented with Tween 80 detergent(final concentration of 05 (vv)) with the exception ofthe yeasts (Sabouraud dextrose broth (SDB) + Tween 80)Bacterial strainswere cultured overnight at 37∘C inMHB andthe yeasts were cultured overnight at 30∘C in SDB Geometricdilutions ranging from 200 to 2500120583gmL of the compoundswere prepared including one growth control (MHB + Tween80) and one sterility control (MHB + Tween 80 + testoil) Test tubes were incubated under normal atmosphericconditions at 37∘C for 24 h for bacteria and at 30∘C for48 h for the yeasts The microbial growth was determined byturbidimetric methods
27 Oxidation Procedure A mixture of 110minus3mol cat-alyst 20mL solvent (CH
3CN) and 10mmol cyclohex-
enestyrene was stirred under nitrogen atmosphere in a50mL round-bottom flask equipped with a condenser anda dropping funnel at room temperature for 30min Then20mmol hydrogen peroxide (30 in water) was added(catalyst substrate oxidant ratio is 1 10 20) The resultingmixture was then refluxed for 8 h under nitrogen atmosphereat 90∘C After filtration and washing with solvent the filtratewas concentrated and then subjected to GC analysis Theyields were recorded as the GC yield based on the startingstyrene or cyclohexeneThe identity of the oxidation productswas confirmed by GC-MS A blank reaction was also carriedout without any catalyst for both oxidation reactions
3 Results and Discussion
31 IR and UV Spectra of the Ligands and the ComplexesIR spectrum of 9-ethyl-3-formylcarbazole revealed the char-acteristic weak C-H stretching bands belonging to aromaticrings at 1591 cmminus1 1622 cmminus1 2850 cmminus1 and 2922 cmminus1 Thelatter two bandsmight also be the C-H stretching frequenciesgenerally observed for saturatedmethyl ormethylene groupsThe aromatic aldehyde was observed at 1681 cmminus1 Followingthe imine formation this band was replaced for the iminestretching frequencies at 1638 cmminus1 for L1 and at 1646 cmminus1for L2 In the IR spectra of L1 and L2 the weak bandsbetween 2821 and 2973 cmminus1 belong to weak aromatic andsaturated C-H stretchings The medium strength bands at1598 cmminus1 for L1 and at 1595 cmminus1 for L2 belong to aryl-Hvibrations If we examine the substitution patterns of the
Advances in Chemistry 5
Curr
ent (
120583A
)
Potential (V)
10
0
minus10
minus1 0 1
(a)
Curr
ent (
120583A
)
0
minus10
Potential (V)minus1 0 1
5
minus5
2
(b)
Figure 2 (a) Cyclic voltammogram of L1 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 100mVsminus1 (b) Cyclic
voltammogram of L1-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 500mVsminus1
benzene rings we can say that one metadisubstituted (strongaryl-H vibrations at 806 cmminus1 for L1 and at 809 cmminus1 forL2) and one orthodisubstituted benzene ring (strong aryl-H vibrations at 740 cmminus1 for L1 and at 747 cmminus1 for L2) arepresent in our ligands
Following the coordination the imine frequenciesrecorded for the ligands were red shifted and appearedat around 1575 cmminus1 for L1-Co 1589 cmminus1 for L1-Mn1550 cmminus1 for L2-Co and 1540 cmminus1 for L2-Mn complexesas weak signals All the coordination compounds showedcoordinated water frequencies between 3252 and 3306 cmminus1[45] The M-N stretching vibrations observed between 439and 553 cmminus1 proved that the nitrogens of the imine groupscoordinate with the central metal atoms
The UV spectra of all ligands and the complexeswere taken in ethanol in the range between 200 nm and700 nm For the complex compounds the d-d transitionswere observed between 560 nm and 640 nm and the bandsobserved in the 395ndash367 nm range for these complexes canbe attributed to the charge transfer bands from ligand tometal or from metal to ligand centre [46 47] The 119899-120587lowast and120587-120587lowast transitions of the synthesized ligands and complexeswere observed in 202ndash334 nm region The O-H stretchingfrequencies in watermolecules assisting in coordinationwereseen as broad singlets between 3306 cmminus1 and 3350 cmminus1 [45]All the infrared and uv results are given in the experimentalSections 22ndash24 The magnetic moment values for cobaltcomplexes were recorded as 435 BM and 489 BM whichare characteristic values for tetrahedral cobalt complexes [4647] The manganese(II) complexes gave 585 BM and 623BM values indicating a high spin complex and suggestingtetrahedral geometry [48 49]
32 Electrochemical Properties of the Synthesized CompoundsCyclic voltammogram studies were run inDMF (1 times 10minus3M)ndash01M NBu
4BF4as supporting electrolyte at 293K Electronic
spectra of all the compounds were taken for scan rates 100
250 500 750 and 1000mVsminus1 against an internal ferrocene-ferrocenium standard and we have obtained different oxi-dation and reduction processes for different scan ratesExamination of cv graphics of L1 shows reversible oxidation-reduction processes for the scan rate 100mVsminus1 (Figure 2(a))at 087 V(119864pc) and 088 V(119864pa) (119868pc 119868pa = 1) and for the scanrate 500mVsminus1 at 094V(119864pc) and 104 V(119864pa) (119868pc 119868pa cong 1)The quasireversible processes were observed for 250mVsminus1scan rate at 087V(119864pc) and 10 V(119864pa) and for 750mVsminus1 at09 V(119864pc) and 112 V(119864pa) The rest of the peaks observedfor different scan rates can be said to be irreversible The cvgraphics of cobalt(II) complex of this ligand shows reversibleredox processes for the scan rates 100 500 and 750mVsminus1for example for 500mVsminus1 (Figure 2(b)) the 119868pc 119868pa ratioequals 09 cong 1 (119864pc = 093V and 119864pa = 103V) The otherpeak potentials recorded for this complex gave either quasire-versible or irreversible redoxes The manganese(II) complexof the same ligand gave reversible processes for the scanrates 100 250 and 500mVsminus1 for example for 100mVsminus1 at098V(119864pc) and at 107V(119864pa) 119868pc 119868pa ratio equals around1 The other ligand L2 revealed reversible redoxes for scanrates 250 500 750 and 1000mVsminus1 For example the scanrate 750mVsminus1 (Figure 3(a)) gave cathodic peak potential at098V and anodic peak potential at 099 (119868pc 119868pa=1) Thecobalt complex of this ligand showed reversible redoxes for100 and 250mVsminus1 (Figure 3(b)) scan rates at 113 V(119864pc) and11 V(119864pa) and at 099V(119864pc) and 11 V(119864pa) respectively Themanganese(II) complex of the same ligand gave reversibleprocesses for 100 and 500mVsminus1 The rest of the data can beseen in Table 1 The redox processes for all the complexes canbe defined as the formation of M(II) or M(I) with a simpleone-electron process [24 25] The possible redox process forthe ligands can be shown as in Figure 4
33ThermalAnalysis Thermal gravimetric analysis was usedto explore the thermal stability of these newly synthesizedcompounds and to verify the status of water or solvent
6 Advances in Chemistry
Curr
ent (
120583A
) 0
Potential (V)minus1 0 1
20
minus20
(a)
Potential (V)minus1 0 1
Curr
ent (
120583A
) 0
20
minus20
(b)
Figure 3 (a) Cyclic voltammogram of L2 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 750mVsminus1 (b) Cyclic
voltammogram of L2-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 250mVsminus1
Table 1 Electrochemical data of the title compounds
Compound Scan rate (mVs) 119864pc (119864pa) (V) 119864
12(V) Δ119864
119901(V)
L1
100 087 minus118 (minus057 088) 088 001250 087 minus006 minus124 (minus048 100) mdash 013500 094 minus008 minus132 (minus042 104) mdash 015750 090 minus012 minus140 (minus038 112) mdash 0221000 090 minus014 minus142 (minus035 114) mdash 024
[Co(L1)(H2O)2]2AcO
100 072 minus114 (minus058 080) mdash 012250 076 minus128 (minus050 093) mdash 017500 093 minus140 (minus046 103) mdash 016750 097 minus147 (minus046 107) mdash 0211000 087 minus154 (minus042 117) mdash 030
[Mn(L1)(H2O)2]2AcO
100 098 minus111 (minus052 107) mdash 009250 098 minus113 (minus054 102) mdash 004500 097 minus128 (minus040 108) mdash 013750 096 minus141 (minus033 126) mdash 0301000 097 minus147 (minus026 122) mdash 025
L2
100 009 minus090 (minus056 minus001 082) mdash minus010250 091 003 minus101 (minus053 093) 092 002500 094 minus002 minus109 (minus050 095) 095 001750 098 minus112 (minus044 099) 099 0011000 096 minus131 (minus035 099) 098 003
[Co(L2)(H2O)2]2AcO
100 113 minus003 minus091 (minus053 014 125) mdash 017250 099 minus007 minus096 (minus047 020 110) 072 012500 096 minus008 minus102 (minus050 113) 076 017750 095 minus119 (minus041 110) mdash 0151000 097 minus142 (minus027 110) mdash 013
[Mn(L2)(H2O)2]2AcO
100 110 minus005 minus092 (minus054 119) mdash 020250 096 001 minus100 (minus049 118) 075 022500 097 013 minus112 (minus042 107) mdash 012750 096 minus122 (minus030 111) mdash 0151000 093 minus143 (minus024 115) mdash 022
Advances in Chemistry 7
NN
R R
HNNH ArArArAr
R R
2H++ 2eminus
minus2H+minus 2eminus
Figure 4 Reversible reduction oxidation processes of the title compounds L1 and L2 in DMF (110minus3M) solution
Wei
ght (
)
Temperature (∘C)
100
90
80
70
60
50
40
30
20
10
100 200 300 400 500 600 700 800 900
(a)W
eigh
t (
)
100
80
60
40
20
5
Temperature (∘C)100 200 300 400 500 600 700 800 900
110
(b)
Figure 5 (a) TGplot of L1 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L2-Mn recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Wei
ght (
)
100
90
80
70
60
50
40
30
20
10
Temperature (∘C)100 200 300 400 500 600 700 800 900
(a)
Wei
ght (
)
100
90
80
70
60
50
40
30
20
Temperature (∘C)100 200 300 400 500 600 700 800 900
(b)
Figure 6 (a) TGplot of L2 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L1-Co recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
molecules whether to be inside or outside of the coordinationsphere of the complex compounds [26 50] The resultsof thermal analysis of the title compounds are in goodagreement with the theoretical formulae as suggested fromspectral analyses The thermogram of L1 (Figure 5(a)) showsdecomposition starting around 220∘C with the loss of twoethyl groups adjacent to nitrogen in the carbazole units with12(Calc1197) The biggest loss was observed betweenthe temperatures 340∘C and 520∘C with a percentage of6823(Calc68) which is assigned to the two carbazoleunits The residual part was found as 1987(Calc20)One could also say that the 851(Calc867) of the resid-ual part may belong to the propyl unit which plays abridge role between the two imine groups TG plot of[CoL1(H
2O)2]2AcO complex gives somewhat distorted three
decomposition steps (Figure 6(b)) the first of which is
observed between the temperature ranges 150∘C and 220∘Cwith a 92(Calc10) loss belonging to the two ethyl groupson the nitrogen atoms The second decomposition belongsto two carbazole units with a loss of 5822(Calc5735)The third decomposition step however was assigned asthe loss of C
5H8N2 The residual part gave percentages for
metallic Co and the two water molecules Mn(II) complexof this ligand starts to decompose at around 90∘C Betweenthe temperatures 200∘C and 430∘C our complex shows thehighest percentage loss with 5711(Calc5775) belongingto the carbazole groups Our second ligand L2 decomposesbetween the temperatures 300∘Cand 500∘Cwith a total loss of7632(Calc7617) corresponding to the two carbazoles inour structures (Figure 6(a)) TG graphics of Mn(II) complexof L2 (Figure 5(b)) shows three decomposition stepsThe firstone at 110∘C corresponds to the loss of ethyl groups on the
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
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Volume 2014
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CatalystsJournal of
4 Advances in Chemistry
C 6365(6338) H 671(626) N 966(967) Co 1068(1017)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 256(51000)282(11600) 330(87000) 367(75000) 482(30000)560(33000) FT-IR (KBr cmminus1) 3350 3220(O-H) 29722822 2745(Ar-H C-H) 1575(imine) 439(M-N) 537(M-O)ΛM (Ωminus1 cm2molminus1) 801 120583eff BM 435
242 Manganese(II) Complex of L1 [MnL1(H2O)2]sdot2AcO
complex (C33H36MnN4O2) brown coloured yield 64
mp 198∘C Elemental Analysis found (calculated )C 6923(6886) H 621(630) N 1015(973) Mn 1002(954)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 246(86000)291(51000) 375(24000) 640(12000) FT-IR (KBr cmminus1)3342(O-H) 2847 2730(Ar-H C-H) 1589(imine) 481(M-N)604(M-O) ΛM (Ωminus1 cm2molminus1) 287 120583eff BM 585
243 Cobalt(II) Complex of L2 [CoL2(H2O)2]sdot2AcO com-
plex (C35H40CoN4O2) black coloured yield 60 mp
1465∘C Elemental Analysis found (calculated ) C7009(6918) H 692(663) N 957(922) Co 1001(970)UV-Vis (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 230(120000)284(61000) 384(43000) 620(10200) FT-IR (KBr cmminus1)3306(O-H) 2919 2812(Ar-H C-H) 1550(imine) 553(M-N)654(M-O) ΛM (Ωminus1 cm2molminus1) 673 120583eff BM 489
244 Manganese(II) Complex of L2 [MnL2(H2O)2]sdot2AcO
complex (C33H40MnN4O2) dark green coloured yield 54
mp 119∘C elemental analysis found (calculated )C 7003(6964) H 714(668) N 967(928) Mn 925(910)UV-V is (ethanol) (120582max nm) (120576 Mminus1 cmminus1) 265(90000)395(71000) 567(14000) FT-IR (KBr cmminus1) 3252(O-H) 29202835(Ar-H C-H) 1540(imine) 490(M-N) 601(M-O) ΛM(Ωminus1 cm2molminus1) 352 120583eff BM 623
25 Preparation of Microorganism Culture The growthinhibitory activity of the synthesized compounds was testedagainst 4 gram negative 4 gram positive bacteria (Kleb-siella pneumoniae FMC 5 Escherichia coli DM and Enter-obacter faecium (clinic isolate) and Enterobacter aerogenesATCC 13048 Bacillus subtilis IMG 22 Bacillus megateriumDSM 32 Staphylococcus aureus ATCC 25923 and Strep-tococcus faecalis) and 3 yeasts (Candida albicans ATCC1023 Candida utilis and Saccharomyces cerevisiae WET136) These microorganisms were provided from Microbiol-ogy Laboratory Culture Collection Department of BiologyKahramanmaras Sutcu Imam University Turkey
Antimicrobial activities of the compoundswere deter-mined using the hollow agarThebacteriawere first incubatedat 37 plusmn 01∘C for 24 h in nutrient broth (Difco) and theyeasts were incubated in Sabouraud dextrose broth (Difco)at 25 plusmn 01∘C for 24 h The cultures of the bacteria and yeastwere injected into the Petri dishes (9 cm) in the amount of01mL (McFarland OD 05 15 times 108 bacteriamL and 15 times106 yeastmL) [38 39 41 42] Then Mueller Hinton agar andSabouraud dextrose agar (sterilized in a flask and cooled to45ndash50∘C)were homogeneously distributed onto the sterilizedPetri dishes in the amount of 25mL Finally 2mg of eachchemical compound dissolved in ethanol was placed inside
the sterilised antibiotic discs The prepared antibiotic discswere then placed in the bacterial medium
Afterwards the plates combined with the discs were leftat 4∘C for 2 h the plates injected with yeast were incubatedat 25 plusmn 01∘C for 24 h and ones injected with bacteria wereincubated at 37 plusmn 01∘C for 24 h After 24 h inhibition zonesappearing around the disks were measured and recorded inmm [41ndash44]
26 Determination of Minimal Inhibitory Concentration(MIC) A broth microdilution broth susceptibility assay wasused as recommended by NCCLS for the determination ofthe MIC of the ligand and the complexes and some referencecomponents [38 41] All tests were performed in MuellerHinton broth (MHB) supplemented with Tween 80 detergent(final concentration of 05 (vv)) with the exception ofthe yeasts (Sabouraud dextrose broth (SDB) + Tween 80)Bacterial strainswere cultured overnight at 37∘C inMHB andthe yeasts were cultured overnight at 30∘C in SDB Geometricdilutions ranging from 200 to 2500120583gmL of the compoundswere prepared including one growth control (MHB + Tween80) and one sterility control (MHB + Tween 80 + testoil) Test tubes were incubated under normal atmosphericconditions at 37∘C for 24 h for bacteria and at 30∘C for48 h for the yeasts The microbial growth was determined byturbidimetric methods
27 Oxidation Procedure A mixture of 110minus3mol cat-alyst 20mL solvent (CH
3CN) and 10mmol cyclohex-
enestyrene was stirred under nitrogen atmosphere in a50mL round-bottom flask equipped with a condenser anda dropping funnel at room temperature for 30min Then20mmol hydrogen peroxide (30 in water) was added(catalyst substrate oxidant ratio is 1 10 20) The resultingmixture was then refluxed for 8 h under nitrogen atmosphereat 90∘C After filtration and washing with solvent the filtratewas concentrated and then subjected to GC analysis Theyields were recorded as the GC yield based on the startingstyrene or cyclohexeneThe identity of the oxidation productswas confirmed by GC-MS A blank reaction was also carriedout without any catalyst for both oxidation reactions
3 Results and Discussion
31 IR and UV Spectra of the Ligands and the ComplexesIR spectrum of 9-ethyl-3-formylcarbazole revealed the char-acteristic weak C-H stretching bands belonging to aromaticrings at 1591 cmminus1 1622 cmminus1 2850 cmminus1 and 2922 cmminus1 Thelatter two bandsmight also be the C-H stretching frequenciesgenerally observed for saturatedmethyl ormethylene groupsThe aromatic aldehyde was observed at 1681 cmminus1 Followingthe imine formation this band was replaced for the iminestretching frequencies at 1638 cmminus1 for L1 and at 1646 cmminus1for L2 In the IR spectra of L1 and L2 the weak bandsbetween 2821 and 2973 cmminus1 belong to weak aromatic andsaturated C-H stretchings The medium strength bands at1598 cmminus1 for L1 and at 1595 cmminus1 for L2 belong to aryl-Hvibrations If we examine the substitution patterns of the
Advances in Chemistry 5
Curr
ent (
120583A
)
Potential (V)
10
0
minus10
minus1 0 1
(a)
Curr
ent (
120583A
)
0
minus10
Potential (V)minus1 0 1
5
minus5
2
(b)
Figure 2 (a) Cyclic voltammogram of L1 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 100mVsminus1 (b) Cyclic
voltammogram of L1-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 500mVsminus1
benzene rings we can say that one metadisubstituted (strongaryl-H vibrations at 806 cmminus1 for L1 and at 809 cmminus1 forL2) and one orthodisubstituted benzene ring (strong aryl-H vibrations at 740 cmminus1 for L1 and at 747 cmminus1 for L2) arepresent in our ligands
Following the coordination the imine frequenciesrecorded for the ligands were red shifted and appearedat around 1575 cmminus1 for L1-Co 1589 cmminus1 for L1-Mn1550 cmminus1 for L2-Co and 1540 cmminus1 for L2-Mn complexesas weak signals All the coordination compounds showedcoordinated water frequencies between 3252 and 3306 cmminus1[45] The M-N stretching vibrations observed between 439and 553 cmminus1 proved that the nitrogens of the imine groupscoordinate with the central metal atoms
The UV spectra of all ligands and the complexeswere taken in ethanol in the range between 200 nm and700 nm For the complex compounds the d-d transitionswere observed between 560 nm and 640 nm and the bandsobserved in the 395ndash367 nm range for these complexes canbe attributed to the charge transfer bands from ligand tometal or from metal to ligand centre [46 47] The 119899-120587lowast and120587-120587lowast transitions of the synthesized ligands and complexeswere observed in 202ndash334 nm region The O-H stretchingfrequencies in watermolecules assisting in coordinationwereseen as broad singlets between 3306 cmminus1 and 3350 cmminus1 [45]All the infrared and uv results are given in the experimentalSections 22ndash24 The magnetic moment values for cobaltcomplexes were recorded as 435 BM and 489 BM whichare characteristic values for tetrahedral cobalt complexes [4647] The manganese(II) complexes gave 585 BM and 623BM values indicating a high spin complex and suggestingtetrahedral geometry [48 49]
32 Electrochemical Properties of the Synthesized CompoundsCyclic voltammogram studies were run inDMF (1 times 10minus3M)ndash01M NBu
4BF4as supporting electrolyte at 293K Electronic
spectra of all the compounds were taken for scan rates 100
250 500 750 and 1000mVsminus1 against an internal ferrocene-ferrocenium standard and we have obtained different oxi-dation and reduction processes for different scan ratesExamination of cv graphics of L1 shows reversible oxidation-reduction processes for the scan rate 100mVsminus1 (Figure 2(a))at 087 V(119864pc) and 088 V(119864pa) (119868pc 119868pa = 1) and for the scanrate 500mVsminus1 at 094V(119864pc) and 104 V(119864pa) (119868pc 119868pa cong 1)The quasireversible processes were observed for 250mVsminus1scan rate at 087V(119864pc) and 10 V(119864pa) and for 750mVsminus1 at09 V(119864pc) and 112 V(119864pa) The rest of the peaks observedfor different scan rates can be said to be irreversible The cvgraphics of cobalt(II) complex of this ligand shows reversibleredox processes for the scan rates 100 500 and 750mVsminus1for example for 500mVsminus1 (Figure 2(b)) the 119868pc 119868pa ratioequals 09 cong 1 (119864pc = 093V and 119864pa = 103V) The otherpeak potentials recorded for this complex gave either quasire-versible or irreversible redoxes The manganese(II) complexof the same ligand gave reversible processes for the scanrates 100 250 and 500mVsminus1 for example for 100mVsminus1 at098V(119864pc) and at 107V(119864pa) 119868pc 119868pa ratio equals around1 The other ligand L2 revealed reversible redoxes for scanrates 250 500 750 and 1000mVsminus1 For example the scanrate 750mVsminus1 (Figure 3(a)) gave cathodic peak potential at098V and anodic peak potential at 099 (119868pc 119868pa=1) Thecobalt complex of this ligand showed reversible redoxes for100 and 250mVsminus1 (Figure 3(b)) scan rates at 113 V(119864pc) and11 V(119864pa) and at 099V(119864pc) and 11 V(119864pa) respectively Themanganese(II) complex of the same ligand gave reversibleprocesses for 100 and 500mVsminus1 The rest of the data can beseen in Table 1 The redox processes for all the complexes canbe defined as the formation of M(II) or M(I) with a simpleone-electron process [24 25] The possible redox process forthe ligands can be shown as in Figure 4
33ThermalAnalysis Thermal gravimetric analysis was usedto explore the thermal stability of these newly synthesizedcompounds and to verify the status of water or solvent
6 Advances in Chemistry
Curr
ent (
120583A
) 0
Potential (V)minus1 0 1
20
minus20
(a)
Potential (V)minus1 0 1
Curr
ent (
120583A
) 0
20
minus20
(b)
Figure 3 (a) Cyclic voltammogram of L2 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 750mVsminus1 (b) Cyclic
voltammogram of L2-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 250mVsminus1
Table 1 Electrochemical data of the title compounds
Compound Scan rate (mVs) 119864pc (119864pa) (V) 119864
12(V) Δ119864
119901(V)
L1
100 087 minus118 (minus057 088) 088 001250 087 minus006 minus124 (minus048 100) mdash 013500 094 minus008 minus132 (minus042 104) mdash 015750 090 minus012 minus140 (minus038 112) mdash 0221000 090 minus014 minus142 (minus035 114) mdash 024
[Co(L1)(H2O)2]2AcO
100 072 minus114 (minus058 080) mdash 012250 076 minus128 (minus050 093) mdash 017500 093 minus140 (minus046 103) mdash 016750 097 minus147 (minus046 107) mdash 0211000 087 minus154 (minus042 117) mdash 030
[Mn(L1)(H2O)2]2AcO
100 098 minus111 (minus052 107) mdash 009250 098 minus113 (minus054 102) mdash 004500 097 minus128 (minus040 108) mdash 013750 096 minus141 (minus033 126) mdash 0301000 097 minus147 (minus026 122) mdash 025
L2
100 009 minus090 (minus056 minus001 082) mdash minus010250 091 003 minus101 (minus053 093) 092 002500 094 minus002 minus109 (minus050 095) 095 001750 098 minus112 (minus044 099) 099 0011000 096 minus131 (minus035 099) 098 003
[Co(L2)(H2O)2]2AcO
100 113 minus003 minus091 (minus053 014 125) mdash 017250 099 minus007 minus096 (minus047 020 110) 072 012500 096 minus008 minus102 (minus050 113) 076 017750 095 minus119 (minus041 110) mdash 0151000 097 minus142 (minus027 110) mdash 013
[Mn(L2)(H2O)2]2AcO
100 110 minus005 minus092 (minus054 119) mdash 020250 096 001 minus100 (minus049 118) 075 022500 097 013 minus112 (minus042 107) mdash 012750 096 minus122 (minus030 111) mdash 0151000 093 minus143 (minus024 115) mdash 022
Advances in Chemistry 7
NN
R R
HNNH ArArArAr
R R
2H++ 2eminus
minus2H+minus 2eminus
Figure 4 Reversible reduction oxidation processes of the title compounds L1 and L2 in DMF (110minus3M) solution
Wei
ght (
)
Temperature (∘C)
100
90
80
70
60
50
40
30
20
10
100 200 300 400 500 600 700 800 900
(a)W
eigh
t (
)
100
80
60
40
20
5
Temperature (∘C)100 200 300 400 500 600 700 800 900
110
(b)
Figure 5 (a) TGplot of L1 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L2-Mn recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Wei
ght (
)
100
90
80
70
60
50
40
30
20
10
Temperature (∘C)100 200 300 400 500 600 700 800 900
(a)
Wei
ght (
)
100
90
80
70
60
50
40
30
20
Temperature (∘C)100 200 300 400 500 600 700 800 900
(b)
Figure 6 (a) TGplot of L2 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L1-Co recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
molecules whether to be inside or outside of the coordinationsphere of the complex compounds [26 50] The resultsof thermal analysis of the title compounds are in goodagreement with the theoretical formulae as suggested fromspectral analyses The thermogram of L1 (Figure 5(a)) showsdecomposition starting around 220∘C with the loss of twoethyl groups adjacent to nitrogen in the carbazole units with12(Calc1197) The biggest loss was observed betweenthe temperatures 340∘C and 520∘C with a percentage of6823(Calc68) which is assigned to the two carbazoleunits The residual part was found as 1987(Calc20)One could also say that the 851(Calc867) of the resid-ual part may belong to the propyl unit which plays abridge role between the two imine groups TG plot of[CoL1(H
2O)2]2AcO complex gives somewhat distorted three
decomposition steps (Figure 6(b)) the first of which is
observed between the temperature ranges 150∘C and 220∘Cwith a 92(Calc10) loss belonging to the two ethyl groupson the nitrogen atoms The second decomposition belongsto two carbazole units with a loss of 5822(Calc5735)The third decomposition step however was assigned asthe loss of C
5H8N2 The residual part gave percentages for
metallic Co and the two water molecules Mn(II) complexof this ligand starts to decompose at around 90∘C Betweenthe temperatures 200∘C and 430∘C our complex shows thehighest percentage loss with 5711(Calc5775) belongingto the carbazole groups Our second ligand L2 decomposesbetween the temperatures 300∘Cand 500∘Cwith a total loss of7632(Calc7617) corresponding to the two carbazoles inour structures (Figure 6(a)) TG graphics of Mn(II) complexof L2 (Figure 5(b)) shows three decomposition stepsThe firstone at 110∘C corresponds to the loss of ethyl groups on the
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Advances in Chemistry 5
Curr
ent (
120583A
)
Potential (V)
10
0
minus10
minus1 0 1
(a)
Curr
ent (
120583A
)
0
minus10
Potential (V)minus1 0 1
5
minus5
2
(b)
Figure 2 (a) Cyclic voltammogram of L1 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 100mVsminus1 (b) Cyclic
voltammogram of L1-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 500mVsminus1
benzene rings we can say that one metadisubstituted (strongaryl-H vibrations at 806 cmminus1 for L1 and at 809 cmminus1 forL2) and one orthodisubstituted benzene ring (strong aryl-H vibrations at 740 cmminus1 for L1 and at 747 cmminus1 for L2) arepresent in our ligands
Following the coordination the imine frequenciesrecorded for the ligands were red shifted and appearedat around 1575 cmminus1 for L1-Co 1589 cmminus1 for L1-Mn1550 cmminus1 for L2-Co and 1540 cmminus1 for L2-Mn complexesas weak signals All the coordination compounds showedcoordinated water frequencies between 3252 and 3306 cmminus1[45] The M-N stretching vibrations observed between 439and 553 cmminus1 proved that the nitrogens of the imine groupscoordinate with the central metal atoms
The UV spectra of all ligands and the complexeswere taken in ethanol in the range between 200 nm and700 nm For the complex compounds the d-d transitionswere observed between 560 nm and 640 nm and the bandsobserved in the 395ndash367 nm range for these complexes canbe attributed to the charge transfer bands from ligand tometal or from metal to ligand centre [46 47] The 119899-120587lowast and120587-120587lowast transitions of the synthesized ligands and complexeswere observed in 202ndash334 nm region The O-H stretchingfrequencies in watermolecules assisting in coordinationwereseen as broad singlets between 3306 cmminus1 and 3350 cmminus1 [45]All the infrared and uv results are given in the experimentalSections 22ndash24 The magnetic moment values for cobaltcomplexes were recorded as 435 BM and 489 BM whichare characteristic values for tetrahedral cobalt complexes [4647] The manganese(II) complexes gave 585 BM and 623BM values indicating a high spin complex and suggestingtetrahedral geometry [48 49]
32 Electrochemical Properties of the Synthesized CompoundsCyclic voltammogram studies were run inDMF (1 times 10minus3M)ndash01M NBu
4BF4as supporting electrolyte at 293K Electronic
spectra of all the compounds were taken for scan rates 100
250 500 750 and 1000mVsminus1 against an internal ferrocene-ferrocenium standard and we have obtained different oxi-dation and reduction processes for different scan ratesExamination of cv graphics of L1 shows reversible oxidation-reduction processes for the scan rate 100mVsminus1 (Figure 2(a))at 087 V(119864pc) and 088 V(119864pa) (119868pc 119868pa = 1) and for the scanrate 500mVsminus1 at 094V(119864pc) and 104 V(119864pa) (119868pc 119868pa cong 1)The quasireversible processes were observed for 250mVsminus1scan rate at 087V(119864pc) and 10 V(119864pa) and for 750mVsminus1 at09 V(119864pc) and 112 V(119864pa) The rest of the peaks observedfor different scan rates can be said to be irreversible The cvgraphics of cobalt(II) complex of this ligand shows reversibleredox processes for the scan rates 100 500 and 750mVsminus1for example for 500mVsminus1 (Figure 2(b)) the 119868pc 119868pa ratioequals 09 cong 1 (119864pc = 093V and 119864pa = 103V) The otherpeak potentials recorded for this complex gave either quasire-versible or irreversible redoxes The manganese(II) complexof the same ligand gave reversible processes for the scanrates 100 250 and 500mVsminus1 for example for 100mVsminus1 at098V(119864pc) and at 107V(119864pa) 119868pc 119868pa ratio equals around1 The other ligand L2 revealed reversible redoxes for scanrates 250 500 750 and 1000mVsminus1 For example the scanrate 750mVsminus1 (Figure 3(a)) gave cathodic peak potential at098V and anodic peak potential at 099 (119868pc 119868pa=1) Thecobalt complex of this ligand showed reversible redoxes for100 and 250mVsminus1 (Figure 3(b)) scan rates at 113 V(119864pc) and11 V(119864pa) and at 099V(119864pc) and 11 V(119864pa) respectively Themanganese(II) complex of the same ligand gave reversibleprocesses for 100 and 500mVsminus1 The rest of the data can beseen in Table 1 The redox processes for all the complexes canbe defined as the formation of M(II) or M(I) with a simpleone-electron process [24 25] The possible redox process forthe ligands can be shown as in Figure 4
33ThermalAnalysis Thermal gravimetric analysis was usedto explore the thermal stability of these newly synthesizedcompounds and to verify the status of water or solvent
6 Advances in Chemistry
Curr
ent (
120583A
) 0
Potential (V)minus1 0 1
20
minus20
(a)
Potential (V)minus1 0 1
Curr
ent (
120583A
) 0
20
minus20
(b)
Figure 3 (a) Cyclic voltammogram of L2 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 750mVsminus1 (b) Cyclic
voltammogram of L2-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 250mVsminus1
Table 1 Electrochemical data of the title compounds
Compound Scan rate (mVs) 119864pc (119864pa) (V) 119864
12(V) Δ119864
119901(V)
L1
100 087 minus118 (minus057 088) 088 001250 087 minus006 minus124 (minus048 100) mdash 013500 094 minus008 minus132 (minus042 104) mdash 015750 090 minus012 minus140 (minus038 112) mdash 0221000 090 minus014 minus142 (minus035 114) mdash 024
[Co(L1)(H2O)2]2AcO
100 072 minus114 (minus058 080) mdash 012250 076 minus128 (minus050 093) mdash 017500 093 minus140 (minus046 103) mdash 016750 097 minus147 (minus046 107) mdash 0211000 087 minus154 (minus042 117) mdash 030
[Mn(L1)(H2O)2]2AcO
100 098 minus111 (minus052 107) mdash 009250 098 minus113 (minus054 102) mdash 004500 097 minus128 (minus040 108) mdash 013750 096 minus141 (minus033 126) mdash 0301000 097 minus147 (minus026 122) mdash 025
L2
100 009 minus090 (minus056 minus001 082) mdash minus010250 091 003 minus101 (minus053 093) 092 002500 094 minus002 minus109 (minus050 095) 095 001750 098 minus112 (minus044 099) 099 0011000 096 minus131 (minus035 099) 098 003
[Co(L2)(H2O)2]2AcO
100 113 minus003 minus091 (minus053 014 125) mdash 017250 099 minus007 minus096 (minus047 020 110) 072 012500 096 minus008 minus102 (minus050 113) 076 017750 095 minus119 (minus041 110) mdash 0151000 097 minus142 (minus027 110) mdash 013
[Mn(L2)(H2O)2]2AcO
100 110 minus005 minus092 (minus054 119) mdash 020250 096 001 minus100 (minus049 118) 075 022500 097 013 minus112 (minus042 107) mdash 012750 096 minus122 (minus030 111) mdash 0151000 093 minus143 (minus024 115) mdash 022
Advances in Chemistry 7
NN
R R
HNNH ArArArAr
R R
2H++ 2eminus
minus2H+minus 2eminus
Figure 4 Reversible reduction oxidation processes of the title compounds L1 and L2 in DMF (110minus3M) solution
Wei
ght (
)
Temperature (∘C)
100
90
80
70
60
50
40
30
20
10
100 200 300 400 500 600 700 800 900
(a)W
eigh
t (
)
100
80
60
40
20
5
Temperature (∘C)100 200 300 400 500 600 700 800 900
110
(b)
Figure 5 (a) TGplot of L1 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L2-Mn recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Wei
ght (
)
100
90
80
70
60
50
40
30
20
10
Temperature (∘C)100 200 300 400 500 600 700 800 900
(a)
Wei
ght (
)
100
90
80
70
60
50
40
30
20
Temperature (∘C)100 200 300 400 500 600 700 800 900
(b)
Figure 6 (a) TGplot of L2 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L1-Co recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
molecules whether to be inside or outside of the coordinationsphere of the complex compounds [26 50] The resultsof thermal analysis of the title compounds are in goodagreement with the theoretical formulae as suggested fromspectral analyses The thermogram of L1 (Figure 5(a)) showsdecomposition starting around 220∘C with the loss of twoethyl groups adjacent to nitrogen in the carbazole units with12(Calc1197) The biggest loss was observed betweenthe temperatures 340∘C and 520∘C with a percentage of6823(Calc68) which is assigned to the two carbazoleunits The residual part was found as 1987(Calc20)One could also say that the 851(Calc867) of the resid-ual part may belong to the propyl unit which plays abridge role between the two imine groups TG plot of[CoL1(H
2O)2]2AcO complex gives somewhat distorted three
decomposition steps (Figure 6(b)) the first of which is
observed between the temperature ranges 150∘C and 220∘Cwith a 92(Calc10) loss belonging to the two ethyl groupson the nitrogen atoms The second decomposition belongsto two carbazole units with a loss of 5822(Calc5735)The third decomposition step however was assigned asthe loss of C
5H8N2 The residual part gave percentages for
metallic Co and the two water molecules Mn(II) complexof this ligand starts to decompose at around 90∘C Betweenthe temperatures 200∘C and 430∘C our complex shows thehighest percentage loss with 5711(Calc5775) belongingto the carbazole groups Our second ligand L2 decomposesbetween the temperatures 300∘Cand 500∘Cwith a total loss of7632(Calc7617) corresponding to the two carbazoles inour structures (Figure 6(a)) TG graphics of Mn(II) complexof L2 (Figure 5(b)) shows three decomposition stepsThe firstone at 110∘C corresponds to the loss of ethyl groups on the
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
6 Advances in Chemistry
Curr
ent (
120583A
) 0
Potential (V)minus1 0 1
20
minus20
(a)
Potential (V)minus1 0 1
Curr
ent (
120583A
) 0
20
minus20
(b)
Figure 3 (a) Cyclic voltammogram of L2 in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 750mVsminus1 (b) Cyclic
voltammogram of L2-Co in the presence of 01M NBu4BF4in DMF solution at 110minus3M at 250mVsminus1
Table 1 Electrochemical data of the title compounds
Compound Scan rate (mVs) 119864pc (119864pa) (V) 119864
12(V) Δ119864
119901(V)
L1
100 087 minus118 (minus057 088) 088 001250 087 minus006 minus124 (minus048 100) mdash 013500 094 minus008 minus132 (minus042 104) mdash 015750 090 minus012 minus140 (minus038 112) mdash 0221000 090 minus014 minus142 (minus035 114) mdash 024
[Co(L1)(H2O)2]2AcO
100 072 minus114 (minus058 080) mdash 012250 076 minus128 (minus050 093) mdash 017500 093 minus140 (minus046 103) mdash 016750 097 minus147 (minus046 107) mdash 0211000 087 minus154 (minus042 117) mdash 030
[Mn(L1)(H2O)2]2AcO
100 098 minus111 (minus052 107) mdash 009250 098 minus113 (minus054 102) mdash 004500 097 minus128 (minus040 108) mdash 013750 096 minus141 (minus033 126) mdash 0301000 097 minus147 (minus026 122) mdash 025
L2
100 009 minus090 (minus056 minus001 082) mdash minus010250 091 003 minus101 (minus053 093) 092 002500 094 minus002 minus109 (minus050 095) 095 001750 098 minus112 (minus044 099) 099 0011000 096 minus131 (minus035 099) 098 003
[Co(L2)(H2O)2]2AcO
100 113 minus003 minus091 (minus053 014 125) mdash 017250 099 minus007 minus096 (minus047 020 110) 072 012500 096 minus008 minus102 (minus050 113) 076 017750 095 minus119 (minus041 110) mdash 0151000 097 minus142 (minus027 110) mdash 013
[Mn(L2)(H2O)2]2AcO
100 110 minus005 minus092 (minus054 119) mdash 020250 096 001 minus100 (minus049 118) 075 022500 097 013 minus112 (minus042 107) mdash 012750 096 minus122 (minus030 111) mdash 0151000 093 minus143 (minus024 115) mdash 022
Advances in Chemistry 7
NN
R R
HNNH ArArArAr
R R
2H++ 2eminus
minus2H+minus 2eminus
Figure 4 Reversible reduction oxidation processes of the title compounds L1 and L2 in DMF (110minus3M) solution
Wei
ght (
)
Temperature (∘C)
100
90
80
70
60
50
40
30
20
10
100 200 300 400 500 600 700 800 900
(a)W
eigh
t (
)
100
80
60
40
20
5
Temperature (∘C)100 200 300 400 500 600 700 800 900
110
(b)
Figure 5 (a) TGplot of L1 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L2-Mn recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Wei
ght (
)
100
90
80
70
60
50
40
30
20
10
Temperature (∘C)100 200 300 400 500 600 700 800 900
(a)
Wei
ght (
)
100
90
80
70
60
50
40
30
20
Temperature (∘C)100 200 300 400 500 600 700 800 900
(b)
Figure 6 (a) TGplot of L2 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L1-Co recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
molecules whether to be inside or outside of the coordinationsphere of the complex compounds [26 50] The resultsof thermal analysis of the title compounds are in goodagreement with the theoretical formulae as suggested fromspectral analyses The thermogram of L1 (Figure 5(a)) showsdecomposition starting around 220∘C with the loss of twoethyl groups adjacent to nitrogen in the carbazole units with12(Calc1197) The biggest loss was observed betweenthe temperatures 340∘C and 520∘C with a percentage of6823(Calc68) which is assigned to the two carbazoleunits The residual part was found as 1987(Calc20)One could also say that the 851(Calc867) of the resid-ual part may belong to the propyl unit which plays abridge role between the two imine groups TG plot of[CoL1(H
2O)2]2AcO complex gives somewhat distorted three
decomposition steps (Figure 6(b)) the first of which is
observed between the temperature ranges 150∘C and 220∘Cwith a 92(Calc10) loss belonging to the two ethyl groupson the nitrogen atoms The second decomposition belongsto two carbazole units with a loss of 5822(Calc5735)The third decomposition step however was assigned asthe loss of C
5H8N2 The residual part gave percentages for
metallic Co and the two water molecules Mn(II) complexof this ligand starts to decompose at around 90∘C Betweenthe temperatures 200∘C and 430∘C our complex shows thehighest percentage loss with 5711(Calc5775) belongingto the carbazole groups Our second ligand L2 decomposesbetween the temperatures 300∘Cand 500∘Cwith a total loss of7632(Calc7617) corresponding to the two carbazoles inour structures (Figure 6(a)) TG graphics of Mn(II) complexof L2 (Figure 5(b)) shows three decomposition stepsThe firstone at 110∘C corresponds to the loss of ethyl groups on the
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Advances in Chemistry 7
NN
R R
HNNH ArArArAr
R R
2H++ 2eminus
minus2H+minus 2eminus
Figure 4 Reversible reduction oxidation processes of the title compounds L1 and L2 in DMF (110minus3M) solution
Wei
ght (
)
Temperature (∘C)
100
90
80
70
60
50
40
30
20
10
100 200 300 400 500 600 700 800 900
(a)W
eigh
t (
)
100
80
60
40
20
5
Temperature (∘C)100 200 300 400 500 600 700 800 900
110
(b)
Figure 5 (a) TGplot of L1 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L2-Mn recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Wei
ght (
)
100
90
80
70
60
50
40
30
20
10
Temperature (∘C)100 200 300 400 500 600 700 800 900
(a)
Wei
ght (
)
100
90
80
70
60
50
40
30
20
Temperature (∘C)100 200 300 400 500 600 700 800 900
(b)
Figure 6 (a) TGplot of L2 recorded under nitrogen atmosphere between the temperature ranges 30∘Cand 988∘Cat a heating rate of 10∘Cmin(b) TG plot of L1-Co recorded under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
molecules whether to be inside or outside of the coordinationsphere of the complex compounds [26 50] The resultsof thermal analysis of the title compounds are in goodagreement with the theoretical formulae as suggested fromspectral analyses The thermogram of L1 (Figure 5(a)) showsdecomposition starting around 220∘C with the loss of twoethyl groups adjacent to nitrogen in the carbazole units with12(Calc1197) The biggest loss was observed betweenthe temperatures 340∘C and 520∘C with a percentage of6823(Calc68) which is assigned to the two carbazoleunits The residual part was found as 1987(Calc20)One could also say that the 851(Calc867) of the resid-ual part may belong to the propyl unit which plays abridge role between the two imine groups TG plot of[CoL1(H
2O)2]2AcO complex gives somewhat distorted three
decomposition steps (Figure 6(b)) the first of which is
observed between the temperature ranges 150∘C and 220∘Cwith a 92(Calc10) loss belonging to the two ethyl groupson the nitrogen atoms The second decomposition belongsto two carbazole units with a loss of 5822(Calc5735)The third decomposition step however was assigned asthe loss of C
5H8N2 The residual part gave percentages for
metallic Co and the two water molecules Mn(II) complexof this ligand starts to decompose at around 90∘C Betweenthe temperatures 200∘C and 430∘C our complex shows thehighest percentage loss with 5711(Calc5775) belongingto the carbazole groups Our second ligand L2 decomposesbetween the temperatures 300∘Cand 500∘Cwith a total loss of7632(Calc7617) corresponding to the two carbazoles inour structures (Figure 6(a)) TG graphics of Mn(II) complexof L2 (Figure 5(b)) shows three decomposition stepsThe firstone at 110∘C corresponds to the loss of ethyl groups on the
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
8 Advances in Chemistry
Table 2 Thermal analysis of the ligands and their complexes
Compound MW119879∘C Mass loss
found (calculated) Assignment Residualfound (calculated)
L1 48426 220ndash330340ndash520
1200 (1197)6823 (68)
C2H5C12H8N
1987 (20)
[Co2L1(H2O)2]2AcO 57960
150ndash220220ndash500500ndash700
92 (10)5822 (5735)1617 (165)
C2H5C12H8NC5H8N2
1080 (10) (Co)654 (615) (H2O)
[Mn2L1(H2O)2]2AcO 57560
90ndash200200ndash430430ndash590
103 (10)5711 (5775)168 (166)
C2H5C12H8NC5H8N2
961 (95) (Mn)594 (62) (H2O)
L2 51269 300ndash500 7632 (7617) C14H13N 2404 (2383)
[Co2L2(H2O)2]2AcO 60765 200ndash500
830ndash9005491 (547)2048 (2073)
C12H8NC7H14N2
948 (969) (Co)589 (592) (H2O)
924 (896) (undetermined)
[Mn2L2(H2O)2]2AcO 60366
90ndash150150ndash320400ndash490
1016 (96)5523 (55)209 (2087)
C2H5C12H8NC7H14N2
848 (91) (Mn)523 (543) (H2O)
All thermal analyses were done under nitrogen atmosphere between the temperature ranges 30∘C and 988∘C at a heating rate of 10∘Cmin
Table 3 Oxidation of styrene and cyclohexene
Entry Catalyst Styrene conversion () Selectivity ()Styreneoxide Benzaldehyde Others
1 Blank 115 45 100 8552 [CoL1(H2O)2]2AcO 767 218 445 3373 [CoL2(H2O)2]2AcO 813 174 561 2654 [MnL1(H2O)2]2AcO 853 282 389 3295 [MnL2(H2O)2]2AcO 778 318 405 277
Entry Catalyst Cyclohexene conversion () Selectivity ()Cyclohexeneoxide 2-Cyclohexen-1-one Others
1 Blank 177 7 143 7872 [CoL1(H2O)2]2AcO 65 142 612 2463 [CoL2(H2O)2]2AcO 697 187 583 234 [MnL1(H2O)2]2AcO 712 93 524 3835 [MnL2(H2O)2]2AcO 809 112 64 248Reaction conditions alkene (10mmol) H2O2 (20mmol) catalyst (1mmol) CH3CN (20mL) and nitrogen atmosphere at 90∘C
carbazoles The second stage at 150∘C corresponds to the lossof carbazole groups without the ethylsThe residual part givesa total mass loss of 1371(Calc1453) The cobalt complexof the same ligand however gives the biggest mass loss of5491(Calc547) between 200∘C and 500∘C belonging tothe carbazole units The residual part for this complex gives atotal mass loss of 2461(Calc2457) 924(Calc896) ofwhich can be assigned as the ethyl groups adjacent nitrogenon carbazole rings The thermal data can be examined inTable 2
34 Catalytic Activity Results of the oxidation reactions(Table 3) show the catalytic activity of synthesized complexesComparison between neat and complex catalysed reactionsproves that the oxidation reactions using catalysts give higherconversions than their corresponding neat reactions Exam-ination of Table 3 reveals that the coordination compoundswere most effective towards the oxidation of styrene in
particular the manganese(II) complex gave 282 and 318selectivities for styreneoxide Oxidation of cyclohexene onthe other hand gave poorer results compared to those ofstyrene oxidation Higher selectivities (142 and 187)wereobtained for cyclohexeneoxide by using cobalt(II) complexesas catalyst Comparing our results to those reported previ-ously we can say that our compounds and their catalyticactivity results although not whole have similarities withsalen and salophane type Schiff bases reported previously[8 12 18 51] The oxidation schemes for both styrene andcyclohexene can be seen in Figure 7
35 Antimicrobial Activity and Minimal Inhibitory Concen-tration (MIC) Analysis The title compounds were evaluatedfor antimicrobial activity against four gram negative (Kpneumoniae E aerogenes E faecium and E coli) and fourgram positive bacteria (B subtilis S aureus S S feacalisand B megaterium) and fungi (C albicans C utilis and S
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Advances in Chemistry 9
OHO
+ +
1mmolcatalyst
Styrene Styreneoxide Benzaldehyde
Other oxidation products like
benzoic acid phenylacetaldehyde
1-phenylethane-12-diol and undetermined productsH2O2
(a)
O
O
+ +
1mmolcatalyst
Cyclohexene Cyclohexeneoxide 2-Cyclohexeneone
Other oxidation products like 2-cyclohexanoic acid
2-cyclohexene-1-ol and undetermined productsH2O2
(b)
Figure 7 (a) Oxidation reaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C (b) Oxidationreaction of styrene Catalyst substrate oxidant ratio 1 10 20 under nitrogen atmosphere at 90∘C
Table 4 Antimicrobial data of synthesized compounds
Microorganisms CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 18a 15 7 11 15 17E aerogenes 22 17 8 6 12 11E faecium 10 7 12 15 19 21E coli 12 11 10 9 14 16
Gram (+)B subtilis 9 7 mdashb mdash 8 10S aureus 24 21 11 9 13 12S faecalis 22 19 9 7 11 12B megaterium 15 12 mdash 7 11 9
FungiC albicans 11 12 mdash 7 9 8C utilis 27 25 9 10 16 17S cerevisiae 16 14 11 9 12 15
aInhibition zone mmbUndetermined inhibition zone
cerevisiae) All antimicrobial and antifungal tests were per-formed in Mueller Hinton broth Test tubes were incubatedunder normal atmospheric conditions at 37∘C for 24 h forbacteria and at 30∘C for 48 h for the yeasts and the microbialgrowth was determined by turbidimetric methods All thesynthesized compounds were effective for almost all of themicroorganisms in particular for the microorganisms Kpneumoniae E aerogenes S faecalis and S aureus the titleligands brought about bigger inhibition zones Generally
they were most effective both antimicrobial and antifungalAmong the fungi they gave the biggest inhibition zones forC utilis with 27mm and 25mm zones respectively Amongthe coordination compounds the higher values that areboth antimicrobial and antifungal were recorded for themanganese(II) complex compounds (Table 4) Minimal inhi-bition zone experiments revealed that the microorganismsK pneumoniae E aerogenes S faecalis S aureus and Cutiliswere the most sensitive microorganisms with their MIC
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
10 Advances in Chemistry
Table 5 MIC values of the synthesized compounds
Microorganismsa CompoundsL1 L2 L1ndashCo L2ndashCo L1ndashMn L2ndashMn
Gram (minus)K pneumoniae 500 500 1000 1000 500 500E aerogenes 500 500 1000 1000 500 500E faecium 750 1000 750 750 500 500E coli 1000 1000 1000 1000 1000 750
Gram (+)B subtilis 1000 1000 gt2500 gt2500 1000 1000S aureus 500 500 750 1000 500 500S faecalis 500 500 1000 1000 500 500B megaterium 750 1000 gt2500 1000 750 1000
Fungib
C albicans 1000 1000 gt2500 1000 1000 1000C utilis 500 500 1000 1000 500 500S cerevisiae 750 750 1000 1000 750 750
aAll microorganisms tests were performed in Mueller Hinton broth (MHB)bAll fungi tests were performed in Sabouraud dextrose broth (SDB)
values of 500120583gmL to our ligands and theirmanganese com-plexes The other microorganisms were moderately resistantto the synthesized compounds (Table 5)
4 Conclusion
With this work carbazoles containing efficient ligands andcatalysts have been synthesized characterized and used forthe oxidation reactions of styrene and cyclohexene Catalyticactivity results show the highest selectivities for styrene oxideformation and moderate results have been obtained for theoxidation of cyclohexene Thermal analysis results are inagreement with the proposed structures of the ligands andtheir coordination compounds Thermally most stable com-pound is the ligand L2 with the decomposition temperaturestarting at 300∘C Following this is the ligand L1 Among thecoordination compounds cobalt complexes seem to be moreresistant to temperature thanmanganese onesThe biologicalactivity results reveal that both ligands and their Mn(II)complexes are effective as being antimicrobial and antifungalThe cobalt(II) complexes however showmoderate activitiesFinally the electronic features of these compounds have alsobeen reported
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to thank Kahramanmaras SutcuImamUniversity Research Projects CoordinationUnit for thefinancial support
References
[1] J Rudolph K L Reddy J P Chiang and B K Sharp-less ldquoHighly efficient epoxidation of olefins using aqueousH2O2and catalytic methyltrioxorheniumpyridine pyridine-
mediated ligand accelerationrdquo Journal of the AmericanChemicalSociety vol 119 no 26 pp 6189ndash6190 1997
[2] K Sato M Aoki M Ogawa T Hashimoto and R NoyorildquoA practical method for epoxidation of terminal olefins with30 hydrogen peroxide under halide-free conditionsrdquo Journalof Organic Chemistry vol 61 no 23 pp 8310ndash8311 1996
[3] C Venturello and R DAloisio ldquoQuaternary ammoniumtetrakis(diperoxotungsto)phosphates(3-) as a new class of cat-alysts for efficient alkene epoxidation with hydrogen peroxiderdquoJournal of Organic Chemistry vol 53 pp 1553ndash1557 1988
[4] C Coperet H Adolfson and K B Sharpless ldquoA simple andefficient method for epoxidation of terminalalkenesrdquo ChemicalCommunications no 16 pp 1565ndash1566 1997
[5] D E de Vos B F Sels M Reynaers Y V Subba Rao andP A Jacobs ldquoEpoxidation of terminal or electron-deficientolefins with H
2O2 catalysed by Mn-trimethyltriazacyclonane
complexes in the presence of an oxalate bufferrdquo TetrahedronLetters vol 39 no 20 pp 3221ndash3224 1998
[6] F Heshmatpour S Rayati M Afghan Hajiabbas P Abdolalianand B Neumuller ldquoCopper(II) Schiff base complexes derivedfrom 221015840-dimethyl- propandiamine Synthesis characteriza-tion and catalytic performance in the oxidation of styrene andcyclooctenerdquo Polyhedron vol 31 no 1 pp 443ndash450 2012
[7] W Zeng J Li and S Qin ldquoThe effect of aza crown ring bearingsalicylaldimine Schiff bases Mn(III) complexes as catalysts inthe presence of molecular oxygen on the catalytic oxidation ofstyrenerdquo Inorganic Chemistry Communications vol 9 pp 10ndash122006
[8] Y Yang Y Zhang S Hao et al ldquoHeterogenization of func-tionalized Cu(II) and VO(IV) Schiff base complexes by directimmobilization onto amino-modified SBA-15 styrene oxida-tion catalysts with enhanced reactivityrdquo Applied Catalysis AGeneral vol 381 pp 274ndash281 2010
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Advances in Chemistry 11
[9] G Romanowski and J Kira ldquoOxidovanadium(V) complexeswith chiral tridentate Schiff bases derived from R(-)-phenyl-glycinol synthesis spectroscopic characterization and catalyticactivity in the oxidation of sulfides and styrenerdquoPolyhedron vol53 pp 172ndash178 2013
[10] M Silva C Freire B de Castro and J L Figueiredo ldquoStyreneoxidation by manganese Schiff base complexes in zeolite struc-turesrdquo Journal of Molecular Catalysis A Chemical vol 258 no1-2 pp 327ndash333 2006
[11] S Rayati and F Ashouri ldquoPronounced catalytic activity ofoxo-vanadium(IV) Schiff base complexes in the oxidation ofcyclooctene and styrene by tert-butyl hydroperoxiderdquo ComptesRendus Chimie vol 15 no 8 pp 679ndash687 2012
[12] S Rayati S Zakavi M Koliaei A Wojtczak and A Koza-kiewicz ldquoElectron-rich salen-type Schiff base complexes ofCu(II) as catalysts for oxidation of cyclooctene and styrene withtert-butylhydroperoxide a comparison with electron-deficientonesrdquo Inorganic Chemistry Communications vol 13 no 1 pp203ndash207 2010
[13] Y Yang J Guan P Qiu and Q Kan ldquoEnhanced catalytic per-formances by surface silylation of Cu(II) Schiff base-containingSBA-15 in epoxidation of styrene with H
2O2rdquo Applied Surface
Science vol 256 no 10 pp 3346ndash3351 2010[14] G Romanowski ldquoSynthesis characterization and catalytic
activity in the oxidation of sulfides and styrene of vanadium(V)complexes with tridentate Schiff base ligandsrdquo Journal of Molec-ular Catalysis A Chemical vol 368-369 pp 137ndash144 2013
[15] S Mukherjee S Samanta B C Roy and A Bhaumik ldquoEfficientallylic oxidation of cyclohexene catalyzed by immobilized Schiffbase complex using peroxides as oxidantsrdquo Applied Catalysis AGeneral vol 301 no 1 pp 79ndash88 2006
[16] Y Chang Y Lv F Lu F Zha and Z Lei ldquoEfficient allylic oxi-dation of cyclohexene with oxygen catalyzed by chloromethy-lated polystyrene supported tridentate Schiff-base complexesrdquoJournal of Molecular Catalysis A Chemical vol 320 no 1-2 pp56ndash61 2010
[17] M Salavati-Niasari and H Babazadeh-Arani ldquoCyclohexeneoxidation with tert-butylhydroperoxide and hydrogen perox-ide catalyzed by new square-planar manganese(II) cobalt(II)nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexessupported on aluminardquo Journal of Molecular Catalysis A Chem-ical vol 274 no 1-2 pp 58ndash64 2007
[18] M Salavati-Niasari P Salemi and F Davar ldquoOxidation ofcyclohexene with tert-butylhydroperoxide and hydrogenperoxide catalysted by Cu(II) Ni(II) Co(II) and Mn(II)complexes of NN1015840-bis-(120572-methylsalicylidene)-22-dimethylpropane-13-diamine supported on aluminardquoJournal of Molecular Catalysis A Chemical vol 238 no 1-2 pp215ndash222 2005
[19] M Salavati-Niasari M Hassani-Kabutarkhani and F DavarldquoAlumina-supported Mn(II) Co(II) Ni(II) and Cu(II) NN-bis(salicylidene)-22-dimethylpropane-13-diamine complexessynthesis characterization and catalytic oxidation of cyclo-hexene with tert-butylhydroperoxide and hydrogen peroxiderdquoCatalysis Communications vol 7 pp 955ndash962 2006
[20] D Chatterjee S Mukherjee and A Mitra ldquoEpoxidationof olefins with sodium hypochloride catalysed by newNickel IISchiff base complexesrdquo Journal of Molecular CatalysisA vol 154 pp 5ndash8 2000
[21] I Carlescu G Lisa and D Scutaru ldquoThermal stability of someferrocene containing schiff basesrdquo Journal of Thermal Analysisand Calorimetry vol 91 no 2 pp 535ndash540 2008
[22] D Apreutesei G Lisa N Hurduc and D Scutaru ldquoThermalbehavior of some cholesteric estersrdquo Journal ofThermal Analysisand Calorimetry vol 83 no 2 pp 335ndash340 2006
[23] M Tumer D Ekinci F Tumer and A Bulut ldquoSynthesischaracterization and properties of some divalent metal(II)complexes their electrochemical catalytic thermal and antimi-crobial activity studiesrdquo Spectrochimica Acta A vol 67 no 3-4pp 916ndash929 2007
[24] G Ceyhan C Celik S Urus I Demirtas M Elmastas and MTumer ldquoAntioxidant electrochemical thermal antimicrobialand alkane oxidation properties of tridentate Schiff base ligandsand their metal complexesrdquo Spectrochimica Acta Part A vol 81pp 184ndash198 2011
[25] M Aslantas E Kendi N Demir A E Sabik M Tumer andMKertmen ldquoSynthesis spectroscopic structural characterizationelectrochemical and antimicrobial activity studies of the Schiffbase ligand and its transition metal complexesrdquo SpectrochimicaActa A Molecular and Biomolecular Spectroscopy vol 74 no 3pp 617ndash624 2009
[26] M Shebl ldquoSynthesis spectroscopic characterization andantimicrobial activity of binuclear metal complexes of anew asymmetrical Schiff base ligand DNA binding affinity ofcopper(II) complexesrdquo Spectrochimica Acta vol 117 pp 127ndash1372014
[27] Y-T Liu G-D Lian D-W Yin and B-J Su ldquoSynthesis charac-terization and biological activity of ferrocene-based Schiff baseligands and their metal (II) complexesrdquo Spectrochimica Acta Avol 100 pp 131ndash137 2013
[28] T A Yousef G M Abu El-Reash O A El-Gammal and R ABedier ldquoSynthesis characterization optical band gap in vitroantimicrobial activity and DNA cleavage studies of some metalcomplexes of pyridyl thiosemicarbazonerdquo Journal of MolecularStructure vol 1035 pp 307ndash317 2013
[29] D Guo P Wu H Tan L Xia and W Zhou ldquoSynthesisand luminescence properties of novel 4-(N-carbazole methyl)benzoyl hydrazone Schiff basesrdquo Journal of Luminescence vol131 no 7 pp 1272ndash1276 2011
[30] R Tang W Zang Y Luo and J Li ldquoSynthesis fluorescenceproperties of Eu(III) complexes with novel carbazole function-alized 120573-diketone ligandrdquo Journal of Rare Earths vol 27 no 3pp 362ndash367 2009
[31] S Zhao X Liu W Feng X Lu W Wong and W WongldquoEffective enhancement of near-infrared emission by carbazolemodification in the Zn-Nd bimetallic Schiff-base complexesrdquoInorganic Chemistry Communications vol 20 pp 41ndash45 2012
[32] L Yang W Zhu M Fang Q Zhang and C Li ldquoA newcarbazole-based Schiff-base as fluorescent chemosensor forselective detection of Fe3+ andCu2+rdquo SpectrochimicaActaA vol109 pp 186ndash192 2013
[33] J Liu and J-SMiao ldquoBlue electroluminescence of a novel Zn2+-120573-diketone complex with a carbazole moietyrdquoChinese ChemicalLetters vol 25 no 1 pp 69ndash72 2014
[34] B Ruan Y Tian H Zhou et al ldquoSynthesis characterization andin vitro antitumor activity of three organotin(IV) complexeswith carbazole ligandrdquo Inorganica Chimica Acta vol 365 no1 pp 302ndash308 2011
[35] F B Koyuncu S Koyuncu and E Ozdemir ldquoA novel donor-acceptor polymeric electrochromic material containing car-bazole and 18-naphtalimide as subunitrdquo Electrochimica Actavol 55 no 17 pp 4935ndash4941 2010
[36] S Koyuncu B Gultekin C Zafer et al ldquoElectrochemi-cal and optical properties of biphenyl bridged-dicarbazole
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
12 Advances in Chemistry
oligomer films electropolymerization and electrochromismrdquoElectrochimica Acta vol 54 no 24 pp 5694ndash5702 2009
[37] S Koyuncu C Zafer E Sefer et al ldquoA new conductingpolymer of 25-bis(2-thienyl)-1H-(pyrrole) (SNS) containingcarbazole subunit electrochemical optical and electrochromicpropertiesrdquo Synthetic Metals vol 159 no 19-20 pp 2013ndash20212009
[38] Y Liu andM Liu ldquoLangmuir-Blodgett film and acidichromismof a long chain carbazole-containing Schiff baserdquo Thin SolidFilms vol 415 no 1-2 pp 248ndash252 2002
[39] M Grigoras and N Antonoaia ldquoSynthesis and characterizationof some carbazole-based imine polymersrdquo European PolymerJournal vol 41 no 5 pp 1079ndash1089 2005
[40] K R Yoon S Ko S M Lee and H Lee ldquoSynthesis andcharacterization of carbazole derived nonlinear optical dyesrdquoDyes and Pigments vol 75 no 3 pp 567ndash573 2007
[41] NCCLS Performance Standards for Antimicrobial SusceptibilityTesting M100-S9 International Supplement Villanova PaUSA 9th edition 1999
[42] NCCLS Performance Standarts for Antimicrobial Disks Suscep-tibilty Tests Approved Standart M2-A8 NCCLS Wayne PaUSA 8th edition 2003
[43] C H Collins P M Lyne and J M Grange MicrobiologicalMethods Butterworths London UK 1989
[44] L J Bradshaw Laboratory Microbiology Saundes College Pub-lishing Fort Worth Tex USA 4th edition 1992
[45] M Tumer C Celik H Koksal and S Serin ldquoTransition metalcomplexes of bidentate Schiff base ligandsrdquo Transition MetalChemistry vol 24 pp 525ndash532 1999
[46] E Ispir ldquoThe synthesis characterization electrochemicalcharacter catalytic and antimicrobial activity of novel azo-containing Schiff bases and their metal complexesrdquo Dyes andPigments vol 82 no 1 pp 13ndash19 2009
[47] M Tumer N Deligonul A Golcu et al ldquoMixed-ligand cop-per(II) complexes investigation of their spectroscopic catal-ysis antimicrobial and potentiometric propertiesrdquo TransitionMetal Chemistry vol 31 pp 1ndash12 2006
[48] L P Nitha R Aswathy N E Mathews B S Kumari andK Mohanan ldquoSynthesis spectroscopic characterisation DNAcleavage superoxidase dismutase activity and antibacterialproperties of some transitionmetal complexes of a novel biden-tate Schiff base derived from isatin and 2-aminopyrimidinerdquoSpectrochimica Acta A Molecular and Biomolecular Spec-troscopy vol 118 pp 154ndash161 2014
[49] N K Singh and S B Singh ldquoComplexes of 1-isonicotinoyl-4-benzoyl-3-thiosemicarbazide with manganese(II) iron(III)chromium(III) cobalt(II) nickel(II) copper(II) and zinc(II)rdquoTransition Metal Chemistry vol 26 no 4-5 pp 487ndash495 2001
[50] H P Ebrahimi J S Hadi Z A Abdulnabi and Z BolandnazarldquoSpectroscopic thermal analysis and DFT computational stud-ies of salen-type Schiff base complexesrdquo SpectrochimActaA vol117 pp 485ndash492 2014
[51] V Mirkhani M Moghadam S Tangestaninejad I Moham-madpoor-Baltork and N Rasouli ldquoCatalytic oxidation ofolefins with hydrogen peroxide catalyzed by [Fe(III)(salen)Cl]complex covalently linked to polyoxometalaterdquo InorganicChemistry Communications vol 10 no 12 pp 1537ndash1540 2007
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
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