The low intensity (oscillator strength P,....lO-S) of thebands suggests that all the bands are due to forbid-den electric dipole transitions which occur betweenground state and excited state of the [" configura-tion10-12• . . ..

The furan 2-carboxylates showed the usual 2-substituted furan IR vibrations with the skeletalbreathing mode in the region 1000-1005 cm ? whichappears at 1017 cm " for the free acid-". The freefuran 2-carboxylic acid shows a strong v C=O bandat 1670 crn? which splits into symmetrical and asym-metrical stretching bands in the spectra of complexes.The IR spectra of sodium and lanthanide furan 2-car-boxylates show strong absorptions in the regions1582-1558 and 1434-1410 em:" due to Vas COO and

Vs COO modes respectively of the carboxylate group.The bands are broad and probably composed ofmore than one vibrational modes. The differencein the positions of Vas COO and 'Is COO (liv) andthe positions of the bands themselves have been usedto diagonise the nature of carboxylate group14-18.The small value of t:,v (145-124 cm") coupled withthe negative shift of Vas OCO vibration and thepositive shift of V OCO vibration and the decreasein the value of 6.'1 compared to the value for sodiumsalt suggest symmetrical bidentate nature of thecarboxylate anion in the present complexes. Thebroad nature of these bands might probably be dueto intermolecular association of molecules of thecomplex"; It is likely that polymerization isachieved via the carboxylate oxygen atom. Theenvironment about the lanthanide atom would,therefore, comprise six carboxylate oxygen (threebidentate OCO groups) from the carboxylic groupsand three carboxylate oxygen bridging from adjacentmolecules. The failure of the anhydrous complexesto react with pyridine certainly points to their beingco-ordinatively saturated as proposed for the nine-coordinated polymeric lanthanide furan carboxyl-ates-". Three to four new bands in the region below700 ern"! may be due to vLn-O modesw.

The authors thank CSIR, New Delhi for a SRFto AKS, the Department of Atomic Energy for aJRF to SW and Prof. R. C. Kapoor, Head, Depart-ment of Chemistry, Jodhpur University for providinglaboratory facilities.

References1. BAGNALL,K. W., MTP International review of science,

inorganic chemistry, series two, Vol. 7, edited by K. W.BAGNALL(Butterworths, London), 1975, 41.

2. SOLANKI,A. K., NAHAR, K. R. & BHANDARI,A. M., Syn,React. inorg. met-erg, Chem., 8 (1978),335; SINGH,A. K.& PRAKASH,D., J. inorg. nucl. Chem., 40 (1978), 579.

3. BRANDAU,E., Ges. Kern Porsch. m.b.H., Res., KFK-I068,(1970); Chem. Abstr., 75 (1971), 91833m.

4. ROULET, R., FEUZ, J. & Vu, Due, T., Helv. chim. Acta,52 (1960), 2154; KALINNIKOV,V. T., PASYNSKU,A. A.,LARIN, G. M., NOVOTORTSEV,V. M., KUZ'MICHEVA,O. N. & IVANOVA, E. B., Dokl. Akad. Nauk. SSSR, 213(1973), 844; Chern. Abstr., 80 (1974), 698994.

5. NAKANISHI, M. & TUSOLA, A. Chem., Abstr., 62 (1965)6513b; GELFAND L. S., PYTLEWSKI,L. L., CoSGROVE,D. L., MIKULSKI,eM., SPOCA,A. N. & KARAYANNlS,N. M., Inorg, chim. Acta uo., 27 (1978), L97.

6. SOLANKI, A.K. & BHANDARI, A. M., Transition met. Chem.,4 (1979), 325; J. inorg. nucl, Chem., 41 (1979), 1311.

NOTES

7. BRADLEY,D. C, ABAD-EL-HALlM,F. M. & WARDLAW,.W., J. chem. Soc., 1950, 3450. .

8. MISRA,S. N., MISRA,T. N., KAPOOR,R. N. & MEHROTRA,R. C., Chemy Ind., (1963) 120; SANKHLA,B. S., MISRA,

. S. N. & KAPOOR,R. N., Chemy Ind .. (1965), 382; MISRA,S. N., MISRA,T. N. & MEHROTRA,R. C, Aust, J. Chern.•21 (1968), 797.

9. HENRIE,D. E. & CHOPPIN,G. R. J., chem. Phys., 49 (1968),477; SINHA, S. P., Spectrochim. Acta, 22 (1966), 57.

10. HOOOSCHAGEN,J., Physica, 11 (1946), 513.11. JORGENSEN,C. K., Modern aspects of ligand field theory

(North Holland, Amsterdam}, 1971; Jorgensen, C K.,Progr. inorg: Chem., 4 (1962), 73.

12. KARRAKER,D. G., Inorg: Chem., 7 (1968), 473.13. KATRITZKY, A. R., Physical methods of heterocyclic

chemistry. Vol 2 (Academic Press, New York), 1963.14. NAKAMOTO,K., Infrared spectra of inorganic and coordi-

nation compounds (Wiley-Interscience, New York), 1963and references cited therein.

15. OLDHAM,C. & SANDFORD,W. F., J. chem, Soc. Dalton,(t 977), 2068.

16. LEVER,A. B. P. & OGDEN,D., J. chem. Soc. A, (1967),204.17. HOOF, D. L., TISLEY,D. G. & WALTON, R. A., J. chem.

Soc. Dalton, (1973), 200.18. KARRAKER,D. G., J. inorg. nucl. Chem., 31 (1969), 2815.19. MOSELEY,P. T., MTP international review of science,

Inorganic chemistry, series two, Vol. 7, edited by K. W.Bagnall (Butterworths, London), 1975, 65.

20. SINHA,S. P., Complexes of the rare earths (Pergamon Press,Oxford), 1966.

Metal Derivatives of Organophosphorus Compounds :Part I - Tungsten(V) Derivatives

D. M. PURl- & SORANSINGHDepartment of Chemistry, Kurukshetra University,

Kurukshetra 132 119

Received 31 December 1979; accepted 4 March 1980

Reaction between tungsten hexachloride and diphenyl phos-phite has been studied taking different molar ratios of reactantsand under different conditions of temperature, pressure and solventmedia. The products WCI3[P(O)(OC,H.).].{I), WCJ.[OP(O)(OC.H.)][P(O)(OC.H.).](I1), WCI[OP(O)(OC.H,)].(II1), WCI.[P(O)(OC.H,).la(IV), WCI[P(O)(OC,H.),],(V), W[P(O)(OC.H.),]. (VI), W[OP(O)(OCaH.)J.[P(O)(OC.H,).] (VII),and W[OP(O)(OC.H.)] [P(O)(OC.H,).l:. (VIII) have beenisolated. The compounds are orange, sticky viscous liquidsand highly sensitive to moisture. These have been characterisedon the basis of elemental analysis, infrared (near and far) spectraland magnetic susceptibility data. Theinfrared data indicate thecoordination of phosphite units to tungsten atom through phos-phoryl oxygen. The molecular weight determination of complexessuggests a tendency towards polymerisation.

Metal derivatives of organophosphorus com-pounds are gaining commercial importance due

to their use as pesticides, resins, lubricating oil addi-tives and insecticides. Studies on the metal deriva-tives of dialkyl phosphites have been made by severalworkers+" and polymeric products having -O-P-O-bridges have been reported. Tungsten complexes ofpyridine', alkyl cyanide", amines", collidins'v, triethylphosphine and diarsine'? have been studied but littlework seems to have been done on the tungsten com-

..pounds of these organophosphorus. compounds.

. In view of this it was, thoughtof interest to study the

1021

INDIAN J. CHEM., VOL. 19A, OCTOBER 1980

TABLEI-CHARACTERISATION DATA OF THE CoMPLEXESFORMEDBY DIPHENYLPHOSPHITEAND WCl.

Molar ratio Product Found, (Calc.) Magnetic(WClo:DPP) moment

C% H% CI% P% Molecular (B.M.)wtt

1'''· WCl.[P(O)(OC.H.).). 34.90 2.80 14.90 8.05 997 1.81(38.08) (2.64) (14.20) (8.20) (491.85)

1 :2** WCI.[OP(O)(OC.H.») [P(O)(OCaH.).) 34.75 2.77 10.94 9.30 794.30(33.56) (2.33) (11.02) (9.60) (643.80)

1 :2* WCl[OP(O)(OC.H.»). 23.69 2.51 6.90 11.48 922(27.11) (1.88) (6.68) (11.67) (531.4)

1:3· WCl.[P(O)(OC.H.).h 44.51 3.62 7.31 9.28 11.02 1.67(45.29) (3.14) (7.40) (9.75) (953.9)

1:3*'" WCl.[P( 0)( OCs Hi).). 44.85 3.21 7.70 8.10 1078 1.74

WCl[P(O)(OC,H.).).(45.29) (3.14) (7.40) (9.75) (953.0)

1:4* 49.54 3.88 2.92 10.64 1291 1.75(50.03) (3.46) (3.08) (10.80) (1151.35)

1 :4·· WCI[P(O)(OC,H.).), 43.57 3.74 3.10 9.38 1175 1.63(50.03) (3.46) (3.08) (10.80) (1151.35)

1 :5* W[P(O)(OC.H.).), 52.80 3.65 Nil 11.70 1858(53.30) (3.70) (nil) (11.52) (1348.8)

1:5*· W[P(O)(OCeH.).). 51.58 3.66 Nil 11.61 15.85 1.81(53.30) (3.70) (nil) (11.52) (1348.8)

·Reaction in benzene; **reaction in the absence of solvent; +calculated values on the basis of monomeric formula

reaction between tungsten hexachloride and diphenylphosphite.

All the manipulations of air-sensitive materialswere carried out under anhydrous conditions. Allstandard glass joints were used and were properlydried before use. Infrared spectra (near and far)were recorded on a Beckman spectrophotometermodel IR-20.

Molecular weights of the compounds were deter-mined with the help of a Gallenkamp semi-microebulliometer using benzene as the solvent. Magneticsusceptibility measurements were carried out inbenzene solution using the Gouy method.

Tungsten hexachloride (Fluka) was used as suchafter analysis. Diphenyl phosphite (Aldrich) was usedafter distillation. Benzene was dried on sodium wireand then distilled azeotropically.

Estimation of phosphorus was done by precipita-ting phosphorus as magnesium ammonium phos-phate after oxidising the sample with nitric acid andpotassium permanganate. Chlorine was estimatedby the typical wet analysis after using the samplewith sodium carbonate.

Reaction between tungsten hexachloride and diphenylphosphite in different molar ratios in benzene - To asolution of tungsten hexachloride in dry benzeneunder reflux was added dropwise a benzene solutionof diphenyl phosphite in the required amount depend-ing upon the molar ratio in which the reaction wascarried out. There was a change in temperature andsimultaneously hydrogen chloride gas was evolved.The refluxing condenser was connected to the suctionpump and a reduced pressure of about 20 mm wasapplied. After the reaction subsided, the reactionmixture was refluxed at a bath temperature of120-130°. The refluxing was carried out (24-30 hr)till the reaction was complete. The contents werecooled to room temperature. The excess of the ben-zene was distilled off and its traces were removed

1022

in vucuo (1 to 2 mm) at 80°. An orange colouredsticky viscous fluid was obtained in each case.

The products and analytical results are reportedin Table 1.

Reaction between tungsten hexachloride and diphenylphosphite in different molar ratios in absence ofsolvent - To a known amount of tungsten hexa-chloride in a flask was added the required amount ofdiphenyl phosphite. Vigorous evolution of hydrogenchloride gas was observed on mixing the two reactants.The temperature of the mixture rose by 5-10° andit became a paste on shaking. After an interval of afew minutes, evolution of hydrogen chloride gasslowed down and temperature of the mixture loweredto room temperature. The reaction flask was connect-ed to a suction pump ('" 20 mm) and then heatedat 120-130° till the reaction was over (24-30 hr).The contents of the flask were cooled to room tempe-rature. An orange coloured, sticky and viscousfluid product was obtained in each case .• ,Analyticalresults are given in Table 1.

The reaction of tungsten hexachloride with diphenylphosphite has been carried out in refluxing benzenein different molar ratios. The reaction was studied inthe absence of solvent also at higher temperatures.Further, the reaction was studied under reducedpressure ('" 20 mm) to remove the liberated hydrogenchloride so that it did not react with diphenylphosphite and thus related side reactions were avoided.Tungsten hexachloride was reduced first to pentach-

"loride-" and it was actually the pentachloride of tung-sten which reacted with diphenyl phosphite. It wasobserved that successive replacement of chlorinefrom tungsten pentachloride occurred in differentmolar ratios, from 1 : 2 to 1 : 5. At a bath tempera-ture of 120° in the presence of benzene solvent, onlyhydrogen chloride was liberated whereas in theabsence of the solvent (in 1 : 2 molar ratio) the reac-tion proceeded further and phenyl chloride was

NOTES

also liberated. The reaction can be expressed asfollows:

80°WCIs + 2(C6HsO)2P(O)H ----~

in presenceof benzene

I

WCI3[P(0)(OSCSH)2]2

(I)+ 2HCl

WClz[OP(O)(OC6Hs)] [P(O)(OC6HS)J

(II)WC1[OP(O)(OC6Hs)]2

(III)II

----~in absenceof benzene----~

In the absence of solvent the heating was carriedout for about 12 hr.

The reaction in [he molar ratio 1 : 3, 1 : 4 and1 : 5 was also carried out under similar conditionsproducts, WC12[P(0)(OCeHs)2]3 (IV); WCl[P(O)-(OCSHS)J4 (V) and W[P(O)(OCaH5h]& (VI) res-pectively were formed when reaction was carriedout in benzene while at higher temperatures in theabsence of solvent the products W[OP(O)(OCSHS)]2[P(0)(OCaH5h](VII) and W[OP(0)(OC6Hs)] [P~O)(OC6H5)~11(VnI) were obtained from reaction in1 : 3 and 1 : 4 molar ratios respectively. The charac-terisation data of the complexes are given in Table 1.The products are highly sensitive to moisture andhydrolyse on exposure to atmosphere. On keepingfor some time, the colour of the compounds changesthough there is no change in elemental analysis.

The infrared spectra (near and far) of these com-pounds show a strong band in the region 1225-1170ern"! which is assigned to phosphoryl stretching mode.The lowering of frequency from 1265 cm-l for freephosphoryl groupl3,U could be due to coordinationof phosphoryl oxygen to the tungsten atom of theadjascent molecule. The bands for P-O·Ph bondswere observed in the regions 1150-1170 and 1240-1190 cm? (Ref. 13). Band observed in the region875-730 cm-! has been assigned to P-O-(C) stretchingmodels while that in the region 1050-1000 cm? isassigned to (P)-O-C stretching mode. Bands in theregion 980-950 crn? could be due to w-o linkage".Except in the compounds obtained from the reac-tion between tungsten hexachloride and diphenylphosphite in the molar ratio 1 : 5 and the com-pounds in which there was no chlorine left due toheating in the absence of solvent, a band was observedin the region 350-280 crn"", This was assigned tov W-CI. In the range 600-410 cm-1 also bands wereobserved which could be due to Vas and Vs frequen-cies of -O-W-O-linkages in the compounds".

The dialkyl phosphites exist in tautomeric equil-librium of phosphite and phosphonate forms inwhich a much higher percentage consists of thephosphonate form": The reaction presumably occursthrough the formation of an addition compoundbetween tungsten pentachloride and diphenyl phos-phite (coordinating through phosphoryl oxygen)from which then first hydrogen chloride and laterphenyl chloride are liberated.

Molecular weights of compounds were determinedebullioscopically in boiling benzene (Table 1). In

general, a tendency towards dimerisation is shown.It was observed that on prolonged boiling in benzenethe compounds became insoluble there by indicatingan increase in the molecularity of the compounds.Further, if the compounds were heated to 150-170°,they became insoluble in benzene or any other com-mon organic solvent which again confirmed theformation of polymeric compounds containing-O-P-O--linkages.

The magnetic moments of the compounds inbenzene solution were found to be in the range1.50-1.80 B.M. which are in good agreement withthe theoretical value required for the d' system oftungsten(V). The electronic spectra of compound(V)shows a band at 640 nm. A similar band has beenobserved by Jorgensen'? for tungsten(V).

Thanks are due to the authorities of KurukshetraUniversity for providing the facilities. One of us(S.S.) is thankful to the UGC, New Delhi for finan-cial help.

References1. OWENS, c., PYTLEWSKI,L.L., KARAYANNIS,N. M.,

WYSOCZANSKI,J. & LABES,M. M., J. polym. s.i., PartE, 8 (1970), 81.

2. OSIPOV, 0 A., GALVORONSKII,V. 1. & SHVETS, A. A.,Chern, Abstr., 69 (1968). 6592r.

3. OSIPOV, O. A, GALVORONSKII,V. 1. & SHVETS,A. A.,Zh. neorg. Khim., 8 (1963), 2190; Chem. Abstr., 64(1966), 16835c.

4. SMITH, T. D., J. inorg. nucl. Chem., 9 (1959), 150.5. KAUTZNER, B. & WAiLfS, P. c., Aust, J. Chem., 22. (1969), 2295.6. PURl, D. M. & AITAM PARKASH, Indian J. Chem., l3

(1975), 384.'7. MCCARLEY, R. E. & BROWN, T. M., Inorg. Chem., 3

(1964), 1233.8. ALLEN, E. A, BRISDON,B. J. & FOWLES, G. W. A., J.

chem. Soc., (1964), 4531.9. PRASAD, S. & SWARUP, R., J. Indian chem. Soc., 42

(1965), 789.10. BROWN,T. M. & RUBLE,B. R., 151st meeting Amer. Chern.

Soc., H83 (1966), quoted in BOORMAN,P. M., GREENWOOD, N. N., HILDON, M. A. & PARISH,R. V., Inorg.nucl. chem. Left., 2 (l966), 377.

11. BOOTH, G., Advances in inorganic chemistry and radio-chemistry, edited by H. J. Emeleus & A G. Sharpe,Vol. 6 (Academic Press, New York and London),1964, 7.

12. FOWLEs,G. W. A & FROST,J. L., Chem. Commun., (1966),252.

13. DAASCH,L. W. & SMITH,D. C., Analyt, Chem.,23 (1951),853.

14. BELLAMY, L. J. & BEECHER, L., J. chem. Soc., (1952),475, 1701; (1953), 728.

15. CHAPM.<\N,A. C. & HARPER,R., Cherny Ind., (1962), 985.16. ADAMS,D. M., . FRASER, G. W., MORRIS,D. M. &

PEACOCK,R. D., J. chem, Soc., (968), 1131.17. DUPNIS, T. & VILTANGE,M., Mikrochim. Ichnoanal Acta,

(1963), 232, quoted by Ross, S. D. in inorganic infraredand Raman spectra (McGraw Hills, N. Y.), 1972, 337.

18. DOAK, G. O. & FREEMAN,L. D., Chern. Rev., 61 (1961),31.

19. JORGENSEN, C. K., Acta chem. scand., 11 (1957), 73,quoted in Modern coordination chemistry edited byJ. Lewis & R. G. Wilkins (Interscience publishers,New York), 1962, 292.

1023