ISSN 0012�5008, Doklady Chemistry, 2009, Vol. 429, Part 1, pp. 277–282. © Pleiades Publishing, Ltd., 2009.Original Russian Text © M.L. Keshtov, P.V. Petrovskii, A.S. Stakhanov, V.S. Kochurov, A.R. Khokhlov, 2009, published in Doklady Akademii Nauk, 2009, Vol. 429, No. 2,pp. 206–211.

277

Previously, we prepared new representatives ofbis(tetraarylcyclopentadienones) (BTACPDs) [1],monomers used in the synthesis of phenyl�substitutedpolyphenylenes (PSPPs) [2–4] and polyimides(PSPIs) [5] by the Diels–Alder reaction [6]. PSPPsand PSPIs are of considerable interest as polymers thatcombine high thermal characteristics and low dielec�tric constants with good processibility and excellentcomplex�forming properties [7]. Fluorine�containingPSPPs and PSPIs are of special interest because theintroduction of fluorine into polymer macromoleculesleads to a further decrease in dielectric constant andenhancement of polymer solubility [8, 9]. Owing tothese advantages, fluorinated PSPPs attracted consid�erable interest of researchers as interlaminar dielec�trics in multiintegrated circuits. Therefore, in thiswork, we attempted to synthesize previously unknown

fluorinated BTACPDs with fluorine in hexafluoroiso�propylidene core fragments or phenyl rings and tostudy their spectral characteristics.

BTACPDs containing fluorine in phenyl rings(IIIa, IIIb) were obtained by a general procedure usingPd�catalyzed cross�coupling of dihaloarylenes withtwofold molar amounts of phenylacetylene or 4�fluo�rophenylacetylene (similarly to [10, 11]). Bis(phenyl�ethynyl)arylenes and bis(4�fluorophenylethy�nyl)arylenes Ia and Ib thus obtained were oxidizedwith potassium permanganate to, respectively,bis(phenylglyoxalyl)arylenes and bis(4�fluorophe�nylglyoxalyl)arylenes IIa and IIb [9, 10] followed bytheir transformation into BTACPDs by the treatmentwith 1,3�diphenylacetone or 1,3�bis(4�fluorophe�nyl)acetone [1, 12, 13] (Scheme 1).

Scheme 1.

Br Br R R R

R

O O O O

R

O

R'

R'

R

O

R'

'R

R

O

R'

R'

+ 2

KMnO4

[Pd]

2

Ia , Ib

IIa , IIb

IIIa , IIIb

Ia (R = H), Ib (R = F); IIa (R = H), IIb (R = F); IIIa (R = H, R' = F), IIIb (R = F, R' = H).

CHEMISTRY

Novel Fluorine�Containing Bis(tetraarylcyclopentadienones)M. L. Keshtov, P. V. Petrovskii, A. S. Stakhanov, V. S. Kochurov,

and Academician A. R. Khokhlov

Received July 1, 2009

DOI: 10.1134/S0012500809110068

Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, ul. Vavilova 28, Moscow, 119991 Russia

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KESHTOV et al.

The synthesis of BTACPD VIa, containinghexafluoroisopropylidene core fragment, was carriedout by the reaction of 1,1,1,3,3,3�hexafluoro�2,2�bis(4�iodophenyl)propane with a twofold molaramount of phenylacetylene, oxidation of resulting

1,1,1,3,3,3�hexafluoro�2,2�bis(phenylethynyl)pro�pane IVa–IVc into 1,1,1,3,3,3�hexafluoro�2,2�bis(4�phenylglyoxalyl)propane Va–Vc followed by the treat�ment of the latter with a twofold molar amount of 1,3�diphenylacetone (Scheme 2).

IVa (R' = R'' = H), IVb (R'' = H, R' = F), IVc (R'' = CF3, R' = H);Va (R' = R'' = H), Vb (R'' = H, R' = F), Vc (R'' = CF3, R' = H);

VIa (R = R' = R'' = H), VIb (R = R'' = H, R' = F), VIc (R'' = H, R' = R = F), VIe (R'' = CF3, R' = R = F).

Scheme 2.

And finally, BTACPDs VIb–VIe, containing fluo�rine both in the core fragment and in the phenyl ringswere obtained by the reaction of 1,1,1,3,3,3�hexaflu�oro�2,2�bis(4�iodophenyl)propane with a twofoldmolar amount of appropriate fluorine�containing ary�lacetylene followed by oxidation of resulting diethy�nylenes (IVb, IVc) to bis(α�diketones) (Vb, Vc) andtreatment of the latter with 1,3�diphenylacetone or1,3�bis(4�fluorophenyl)acetone (Scheme 2).

It is worth noting that the intermediate compoundsformed in the synthesis of BTACPDs (Schemes 1, 2),namely, diethynylenes (I, IV) and bis(α�diketones (II,V), are of real interest as monomers for the synthesis ofdifferent polymers. Thus, compounds Ia, Ib, and IVa–IVc can be used for the preparation of phenyl�substi�tuted polyphenylenes under conditions of the Diels–Alder reaction and for the preparation of crosslinkedpolyphenylenes; compounds IIa, IIb, and Va–Vc can

I

CF3

I + 2

R''

R'

R''

R'

R''

R''

CF3

CF3

R''

R'

R''

CF3

[Pd]

IVa–IVc

R'

R''

R''

CF3

CF3

R''

R'

R''O O O O

Va–Vc

IVa–IVcKMnO4

O

R

R

R'

O

R

R

R'

CF3

CF3

R''

R''

R''

R''

O

R

R

VIa–VIe

Va–Vc

2

DOKLADY CHEMISTRY Vol. 429 Part 1 2009

NOVEL FLUORINE�CONTAINING BIS(TETRAARYLCYCLOPENTADIENONES) 279

be used in the synthesis of polyquinoxalines,poly(asym�triazines), and poly(aryl ether ketones).

The composition and structure of intermediatecompounds I, II, IV, and V and target compounds IIIand VI were confirmed by the data of elemental anal�ysis (Table 1) and IR and Raman spectroscopy(Table 2). According to the data given in Table 1, allthe intermediate and target compounds were obtained

in high yields and elemental analysis data agree wellwith calculated values. The synthetic route to targetcompounds III and VI was monitored by Raman andFTIR spectroscopy (Table 2). In particular, theRaman spectra of compounds I and IV show strongabsorption bands in the region of 2210–2221 cm–1

typical for acetylene bonds (C≡C) and weak bands inthe region of 1668–1681 cm–1 related to the stretching

Table 1. Certain characteristics of intermediate and final compounds

Compound no. Tm, °C Molecular for�mula

Elemental analysis (calculated/found), %Yield, %

C H F

Ia 184–186 C22H14 – 81

Ib 191–192 C22H12F2 78

IIa 125–127 C22H14O4 – 68

IIb 223–225 C22H12F2O4 67

IIIa 312–314 C52H30F4O2 87

IIIb 325–327 C52H32F2O2 83

IVa 90–91.5 C31H18F6 89

IVb 176–178 C31H16F8 92

IVc 115–117 C35H14F18 81

Va 155–158 C31H18F6O4 95

Vb 111–113 C31H16F8O4 88

Vc 115–117 C35H14F18O4 81

VIa 236–238 C61H38F6O2 87

VIb 178–180 C61H36F8O2 82

VIc 220–222 C61H34F10O2 91

VId 229–231 C61H32F12O2 95

VIe 145–147 C65H34F18O2 95

93.9494.67���������� 5.07

4.98��������

84.0683.92���������� 3.85

3.69�������� 12.09

11.91����������

77.1877.11���������� 4.12

4.22��������

69.8469.43���������� 3.20

3.11�������� 10.09

9.65����������

81.8882.13���������� 3.96

3.73�������� 9.96

9.71��������

85.9585.67���������� 4.43

4.26�������� 5.23

5.00��������

73.8173.66���������� 3.60

3.58�������� 22.60

22.34����������

68.8968.59���������� 2.98

2.87�������� 28.14

28.00����������

54.1454.09���������� 1.80

1.75�������� 44.04

39.65����������

65.5065.32���������� 3.19

3.15�������� 20.05

19.61����������

61.5961.33���������� 2.66

2.42�������� 25.14

24.69����������

50.0249.87���������� 1.68

1.61�������� 40.69

40.31����������

79.8979.58���������� 4.17

4.19�������� 12.43

12.21����������

76.8876.70���������� 3.80

3.94�������� 15.95

15.71����������

74.0973.91���������� 3.70

3.46�������� 19.21

18.94����������

71.4971.09���������� 3.15

3.21�������� 22.24

21.73����������

65.6665.20���������� 2.88

2.93�������� 28.76

28.41����������

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DOKLADY CHEMISTRY Vol. 429 Part 1 2009

KESHTOV et al.

Table 2. Spectral characteristics of intermediate and final compoundsC

ompo

und

no.

NMR spectra, δ, ppm

Raman spectra,ν, cm–1

1H 13C 19F

Ia 2215 7.46–7.52 (m, 4H),7.19–7.24 (m, 6H)

134.68, 131.66, 128.22, 123.48, 114.77, 89.96 (C≡C),89.43 (C≡C)

–

Ib 2219C≡C

7.44–7.54 (m, 8H),7.05 (t, 4H)

163.79, 161.30, 133.47, 131.40, 115.73, 115.51, 90.10 (C≡C), 88.65 (C≡C)

–110.44

IIa 1671CO

8.10 (s, 4H), 7.96 (d, 4H)7.68 (t, 2H), 7.52 (t, 4H)

193.32 (C=O), 193.17 (CO), 137.04 (ч), 135.17, 132.48 (h), 130.16, 129.88, 129.06

–

IIb 1668CO

8.15 (s, 4H), 8.09 (t, 8H),7.47 (t, 8H)

192.44 (C=O), 192.10 (CO), 167.13, 161.56, 134.24, 132.51, 115.99, 115.78

–101.21

IIIa 1709CO

6.60–8.10 (m, 30H) 200.31, 165.05, 162.41, 151.93, 151.55, 137.58, 137.26, 132.45, 132.31, 130.65, 127.10, 126.74, 125.33, 116.57, 116.32

–112.37,–113.05

IIIb 1711CO

7.30–7.72 (m, 22H) 199.21 (C=O), 164.53, 161.95, 159.33, 152.29, 137.33, 135.08, 133.58, 132.86, 132.74, 132.68, 126.95, 126.15, 125.61, 125.31, 115.37, 115.09

–113.15

IVa 2212C≡C

7.20–7.56 (m, 18H) 136.19 (C), 134.32, 131.27 (C), 130.18 (C), 129.63, 129.15, 128.83, 128.31, 127.11, 123.61, 121.55, 116.12, 82.17 (C≡C), 93.95 (C≡C), 65.88, 65.56, 65.31, 65.06, 64.81, 64.56, 64.31

–63.11

IVb 2221C≡C

7.50–7.54 (m, 8H),7.37 (d, 4H),7.05 (t, 4H)

163.85, 161.35, 133.48, 133.17, 132.87, 131.24, 130.07, 128.14, 125.27, 124.14, 122.43, 119.58, 118.78, 115.53, 115.07, 98.89 (C≡C), 87.73 (C≡C), 65.10, 64.85, 64.60, 64.35, 64.09, 63.59

–109.85,–63.32

IVc 2210C≡C

7.96 (s, 4H), 7.84 (s, 2H), 7.57 (d, 4H), 7.42 (d, 4H)

133.78, 132.49, 132.15, 131.81, 131.51, 131.45, 130.23, 125.01, 124.15, 123.02, 121.86, 121.43, 87.8 (C≡C), 91.20 (C≡C), 65.78, 61.16, 65.16, 62.19, 64.49, 62.67, 63.87

–63.11 (12CF3)–63.54 (6CF3)

Va 1681C=O

7.55 (t, 8H); 7.67 (t, 2H), 7.99 (t, 8H)

193.95 (C=O), 193.58 (C=O), 138.17 (C), 135.74, 133.07 (C), 132.08 (C), 130.89, 130.14, 129.89, 129.54, 128.01, 124.91, 122.05, 118.02, 66.88, 64.06, 66.18, 63.16, 65.47, 62.66, 64.77

–63.55 (CF3)

Vb 1683C=O

7.20 (t, 4H), 7.52 (d, 4H),7.96–8.05 (m, 8H)

192.43 (C=O), 191.64 (C=O), 168.13, 165.56, 116.53, 116.31, 132.81, 132.72, 127.68, 133.19, 129.48, 130.73, 139.04, 127.68, 124.83, 121.96, 119.10, 66.88, 64.06, 66.18, 63.16, 65.47, 62.66, 64.77

–62.94 (2CF3)–100.14 (2F)

Vc 1661C=O

7.58 (d, 4H), 8.07 (d, 4H),8.17 (s, 2H), 8.46 (s, 4H)

190.32 (C=O), 189.30 (C=O), 139.62 (C), 134.20 (s), 133.07 (C), 132.72 (s), 130.94, 130.05, 129.90, 129.77, 126.61, 123.87, 121.16, 118.45, 58.38

–63.01 (CF3), –63.18 (CF3)

VIa 1710C=O

7.31–7.13 (m, 22H),7.18–7.14 (m, 8H),6.99–6.91 (d, 4H),6.85 (d.4H)

199.11 (C=O), 154.01 (C), 152.87 (C), 134.67 (C), 132.97 (C), 132.60 (C), 130.36 (C), 130.16 (C), 129.97, 129.59, 129.12, 128.97, 128.61, 127.99, 127.86, 127.69, 127.51, 125.75 (C), 125.05 (C), 123.74 (CF3), 64.22 (t, JCF = 25.4)

–63.45 (CF3)

VIb 1714C=O

7.59–6.80 (m, 36H) 199.77, 164.41, 161.09, 153.03, 152.61, 134.31, 133.22, 131.36, 131.26, 130.35, 130.09, 129.86, 129.76, 129.32, 129.15, 128.74, 128.63, 128.23, 128.16, 127.93, 127.81, 127.25, 127.09, 126.09, 125.43, 115.45, 115.16, 64.89

–63.75 (CF3),–111.23 (F)

VIc 1710C=O

6.90–7.05 (m, 17H)7.20–7.33 (m, 17H)

199.92 (C=O), 164.04, 163.95, 160.75, 160.65, 154.03, 152.84, 134.11, 133.28, 132.50, 131.90, 131.79, 129.86, 129.17, 129.05, 128.04, 128.15, 126.44, 126.39, 126.27, 126.22, 124.87, 124.19, 115.49, 115.45, 115.20, 115.17, 65.07, 64.70, 64.38, 64.38, 64.05

–63.64 (CF3),–112.69 (F),–113.04

VId 1716C=O

6.80–7.10 (m, 20H),7.26–7.40 (m, 12H),

199.65, 164.48, 164.02, 161.15, 160.78, 152.91, 152.44, 134.12, 133.36, 132.55, 132.41, 131.88, 131.78, 131.28, 131.17, 130.71, 130.00, 129.59, 129.05, 128.46, 126.26, 126.11, 125.05, 124.37, 115.90, 115.59, 115.50, 115.30, 115.21, 114.90, 64.11, 63.74

–63.64 (CF3),–110.7 (F),–112.40 (F),–112.73

VIe 1714C=O

8.2–7.29 (m, 34H) 199.28, 158.32, 156.77, 140.56, 139.14, 138.14, 135.11, 128.21, 128.01, 127.77, 126.65, 126.14, 125.81, 125.32, 120.73, 120.57, 120.32, 117.45, 114.61, 111.75, 64.73, 64.45, 64.18, 63.89, 63.61, 63.33, 63.06

–63.18(CF3),–63.58 (CF3)

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NOVEL FLUORINE�CONTAINING BIS(TETRAARYLCYCLOPENTADIENONES) 281

vibrations of CO groups in the α�diketone fragmentsof compounds II and V. The absence of signals of ethy�nyl group in the region of 2210–2221 cm–1 confirmsits complete transformation into α�diketone frag�ment. The IR spectra of target compounds III and VIshow bands in the region of 1709–1716 cm–1 typical ofthe stretching vibrations of the carbonyl group of thetetraphenylcyclopentadienone fragment and the lackof bands at 1668–1681 cm– related to the α�diketonegroups.

The structure of intermediate compounds I, II, IV,V, and target compounds III and VI was also con�firmed by 1H, 13C, and 19F NMR. The 1H NMR spec�tra of compounds Ia and Ib show two multiplets at δ7.46–7.52 (m, 4H), 7.19–7.24 (m, 6H) and 7.44–7.54(m, 8H), 7.05 ppm (t, 4H), respectively. The 1H NMRspectra of bis(α�diketones) IIa and IIb show signals inthe ranges 8.10–7.52 and 8.15–7.47 ppm, which areshifted downfield relative to the signals of diethynylintermediates I on account of the inductive effect ofelectron�withdrawing CO–CO groups. The distinc�tive feature of the 1H NMR spectra of compounds Iand II is the presence of strong singlets related to thecore benzene fragment. The 1H NMR spectra of com�pounds IVb and Vb show in aromatic region two dou�blets at 7.57, 7.53 and 7.99, 7.52 ppm and two multip�lets at 7.51, 7.05 and 8.03, 7.21 ppm which agree wellwith the supposed structures. The 1H NMR spectra ofcompounds IVc and Vc are well resolved and show twocouples of singlets at 7.96, 7.83 and 8.46, 8.10 ppm andtwo doublets at 7.57, 7.41 and 8.07, 7.59 ppm, respec�tively.

Signal assignment in the 1H NMR spectra wasmade on the basis of the integrated intensity ratio andthe values of spin–spin coupling constants. The13C NMR spectra of all bis(ethynyl) compounds I andIV in the region of δ = 80–90 ppm show two intensesignals related to the acetylene fragments. In the caseof compounds IVa–IVc, the spectra of aliphatic moietyshow signals at –63.11 to –63.32 ppm related to thequaternary carbon atom of hexafluoroisopropylidenefragment, which appear as a septet due to two CF3

groups. The spectrum of aromatic moiety of com�pounds IVa–IVc displays a quartet at 119–125 ppmrelated to the carbon atom of CF3 group. Further�more, 13C NMR spectra of bis(ethynyl) compoundIVb also shows a doublet at 163.85–161.43 ppm typi�cal of the carbon atom directly bound to fluorine atomwith the spin coupling constant J = 257.1 Hz. Alongwith the above signals, the 13C NMR spectra of com�pounds IIa, IIb, and Va–Vc also show two peaks in theregion of 189.30–193.95 ppm related to two non�equivalent carbonyls of the bis(α�diketone) fragment,while the lack of signals at 80–90 ppm confirms thecomplete transformation of the ethynyl group into theα�diketone fragment. Along with the noted typicalsignals between 100 and 160 ppm, the spectra of com�

pounds IIa, IIb, Va, and Vc show strong signals relatedto different kinds of carbon atoms, which agree wellwith the suggested structures.

The 19F NMR spectra of compounds Ib and IIbshow signals at –110.44 and –101.21 ppm typical offluorine atoms in the para position to the acetyleneand bis(α�diketone) fragments. The 19F NMR spectraof compounds IV and V exhibit signals at –62.94 to⎯63.35, –109.85, and –100.14 ppm corresponding toCF3 and Ar–F groups.

The 1H NMR spectra of bis(cyclones) III and VIare rather complex and display downfield multiplets inthe range 6.90–7.77 ppm. The 13C NMR spectra aremore informative. The specific feature of the spectraof compounds III and VI is the presence of downfieldsignals in the range of 200.31–199.11 ppm typical ofthe carbonyl group of the cyclopentadienone frag�ment. All 13C NMR spectra of bis(cyclones) VI con�taining hexafluoroisopropylidene fragments show asignal at –63.75 to –63.18 ppm split into septet due toCF3 groups. Along with the above signals, the spec�trum of compound VIb show a doublet signal of aro�matic moiety at 164.41–161.09 ppm typical of the car�bon atom directly bound to fluorine atom. The spectraof compounds VIc and VId exhibit two and four dou�blets at 164.04–163.95 and 160.75–160.67 and164.48–164.38, 164.02–163.93, 161.15–161.06, and160.78–160.68 ppm related to carbon atoms directlybound to two and four nonequivalent fluorine atoms.

ACKNOWLEDGMENTS

This work was supported by the Russian Academyof Sciences, Division of Chemistry and Materials Sci�ence (project no. OKh�2, “Design of New Metallic,Ceramic, Glass, Polymeric, and Composite Mate�rials”).

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