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Synthesis of hydroxyalkyl-substituted bis(ethylenedithio)-tetrathiafulvalene derivatives
ELSEVIER
Synthetic
Metals 89 ( 1997) 91-93
Synthesis of hydroxyalkyl-substituted bis (ethylenedithio) -tetrathiafulvalene derivatives Weiguo Zhao a, Yongjia Shen a3*, Yongfang Li b, Jing Yang b a Institute of Fine Chemicals, East China lJni\aersio h Laboratory of Organic Solids, lmtitute ojChemist>):
of Science rind Technology, Shanghai 200237, China Chinese Academy ojScience, Beijing 100080, Chinci
Received 8 September 1996; accepted 22 April 1997
Abstract Four substituted bis( ethylenedithio)-tetrathiafulvalene (BEDT-TTF) derivatives were synthesized, and their MS and NMR spectra are given. The redox properties of the compounds were studied by cyclic voltammetry. The powder conductivities of the charge-transfercomplexes of the hydroxyalkyl-substituted BEDT-TTF with TCNQ were measured by two-probe contacts. The results show that they are semiconductors. 0 1997 Elsevier Science S.A. Ke>wjords:
Tetrathiafulvalene; Charge-transfer complexes
I. Introduction
CH,COOR
Much effort is still being devoted to improving the electrical properties of radical-cation salts of tetrathiafulvalene (TTF) derivatives [ 11. It is well known that most synthetic metalshave Peierlsdistortion [ 21. Increasingtheir dimension by modifying the TTF framework can stabilize their metallic state (by suppressingPeierlsdistortion) leading to superconductivity at low temperatures[ 31. Therefore, functional TTF derivatives have received much attention [ 41. Recently, we synthesized two new bis( ethylenedithio)tetrathiafulvalene (BEDT-TTF) derivatives (4a and 4b) containing two hydroxyl substituents.Such derivatives are suitable precursors and building blocks, which can further react with acids, anhydrides, halogen compounds,or polymerize with diacids or the correspondingacid chlorides.The synthetic route is shown in Scheme1.
2. Results and discussion The self-coupling reactionsof both thione la-b and ketone 2a-b in triethylphosphite or in a mixture of triethylphosphite and toluene as solvents are successful,only the yields of compound 3 formed are different. The yield starting from ketone 2 is higher than that starting from thione 1. However, compound 3 is not formed if the reaction is carried out in a * Corresponding author. 0379-6779/97/$17.00 PZlSO379-6779(97)03880-O
0 1997 Elsevier Science S.A. All rights reserved
Hg(CH$OO),
CH,COO
(EtOhP/
MeOH
-
la-b
3a-b
KOH
-““‘-f&&&ROH
4
a:R
q
CHZ
b:R
q
C3H,j
Scheme 1.
mixlure of tnethylphosphite andbenzeneassolvents.Perhaps the reaction temperatureis too low, becausethe boiling point of benzene is lower than toluene. The reaction should be carried out under the protection of argon. A red by-product will be formed without the protection of argon. It is very difficult to remove the by-product from the products 3a or 3b. The non-protected hydroxyl group is too reactive in this self-coupling reaction; it reacts with triethylphosphite and causes triethylphosphite to be hydrolyzed. Hence, the hydroxyl group in la-b and 2a-b must be protected, otherwise only a small amount of the target products will be formed. An acetyl group is a suitableprotection group in such reactions. The experiments show that the acetyl group is effective, due to its easy reaction with the hydroxyl group
92 Table 1 Oxidation
11’. Zhno PI ~1. /Spthrtic
potentiais
’ of the compounds
Compound
.Ey
BEDT-TTF 3a 3b 4a 4b
0.54 0.53 0.49 0.47 0.37
(V)
3a-b, E:”
BE”?
0.96 0.92 0.82 0.87 0.85
in CH,CI,,
and removal after the coupling reaction. Two methods can be used to deprotect the acetyl group: one is to alcoholize it with potassium hydroxide in methanol and the other is to reduce it with hydrazine hydrate. Potassium hydroxide in methanol is an efficient alcoholysis reagent to cleave the acetyl group in 3a and 3b; however, hydrazine hydrate is only able to cleave the acetyl group in 3a. Both deprotection reactions are nearly quantitative. The solution redox chemistry of the new TTF derivatives has been studied by cyclic voltammetry. Each donor shows two single electron and reversible redox waves at the expected potentials for TTF derivatives. Their data together with 3EDT-TTF are shown in Table 1. The data in Table 1 show that the reversible redox values of the new TTF derivatives are lower than BEDT-TTF. Therefore, the four derivatives can be considered as promising candidates for organic conductors. 3a and 3b are less easily oxidized than 4a and 4b, presumably because of the electron-withdrawing effect of two ester groups in 3a and 3b. With the extension of the carbon chain, the electron-withdrawing effect of the ester group attenuated quickly, so the value of 3b is similar to that of 4b. The charge-transfer (CT) complexes of four new TTF derivatives with tetracyanoquinodimethane (TCNQ) were obtained by mixing them in hot dichlorobenzene. The conductivities (a) of the pressed pellets of the powdery CT complexes measured by the two-probe technique are shown in Table 2; they are all semiconductors. Attempts to grow crystals by electrocrystallization with Bu,NPF, or Bu,NC104 were unsuccessful; no high quality single crystals were obtained.
3. Experimental 3.1. Aceio~~merhq!lene-sllbstiruren 4,S-erhylerzediti’?ioI,3-dithiole-2-thione (la) and acetoqpropanyl-substituted 4,5-ethplerzedithio-l,3-dithiole-2-thione (Ib)
The general method for the synthesis Ref. [ 51 has been used.
91-93
(a)
of the CT complexes
of the compounds
(3a-b,
(V)
0.42 0.39 0.33 0.40 0.38
a Conditions: Pt electrode, 25 “C, under argon, 0.1 M Bu,NPF, SCE as the reference electrode, scan rate 5 mV s - I.
89 (1997)
Table 2 Powder conductivity 4a-b) with TCNQ
4a-b and BEDT-TTF (V)
Met&
as described in
Compound
v (S cm-‘)
3a 3b 4a 4b
3.18X 1.32x 5.65 x 7.19x
3.2. Acetonymethylene-substituted 1,3-dithiole-2-one (2aj
10-x io-F IO-” 10-l
4,5-eth~lerledirhio-
Thione la (3 g, 0.0 1 mol) was dissolved in a mixture of chloroform (20 ml) and acetic acid (20 ml) ; mercury acetate (9.6 g, 0.03 mol) was added to this solurion. The reaction mixture was stirred at room temperature for 4 h. The white precipitate which formed was filtered off, the filtrate was washed with water, 5% solution of sodium bicarbonate and finally water, and dried with anhydrous sodium sulfate. Solvent was evaporated to yield a light yellow solid (2.6 g, 9.5 mmol); yield 95%; melting point 3X-49 “C. ‘H NMR (CDCI,) 6 (ppm): 2.10 (s, 3H), 3.40 (II-I, 2H), 4.15 (m, IH), 4.40 (d, 2H). MS (EI) m/z: 280 (M+, lOO%), 220 ( 13%). Anal. Found: C, 34.73; H, 3.24. Calc. for C,HBO,S,: C, 34.29; H, 2.86%. 3.3. Acetos?lpropan~ll-srlbstitl{ted I,3-dithiole-2- rhione (2b)
4,5-etl~~ienedit~lio-
The synthesis was the same as in the previous section. The product is a light yellow oil; yield 95%. ‘1-I NMR ( CDCl,) 6 (ppm): 1.85 (m, 4H), 2.15 (s, 3H), 3.18 (m, lH), 3.42 (m, IH), 3.68 (m, 1H), 4.10 (m, 2H). MS (EI) m/z: 308 (M+, 80%), 248 (100%). Aunl. Found: C, 38.61; H, 3.99. Calc. for C10H,203S-I: C, 38.96; H, 3.90%. 3.4. Bis-aceto~~~nethgIene-substitL~tcd4,5-etlzyIenedithioTTF (3a) Method A: Thione la (3.0 g, 0.01 mol) was dissolved in freshly distilled triethylphosphite (20 ml) under argon atmosphere and heated to 1lo-120 “C with stirring for 4 h; the solution became orange. Removal of triethylphosphite under reduced pressure and chromatographic separation of the residue on silica gel (petroleum ether (60-90 “C) :ethyl acetate=2:1 vol./vol.) gave 3a as an orange solid (0.9 g, 3.4 mmol); yield 34%; melting point 90-91 “C. Method B: Ketone 2a (2.8 g, 0.01 mol) was dissolved in freshly distilled triethylphosphite (20 ml) under argon atmosphere and heated to 1 lo-120 “C with stirring for 4 h; the solution became orange. The same workup as Method A gave 3a as an orange solid (2.0 g, 7.5 mmol); yield 75%; melting point 90-9 1 “C. Method C: Ketone 2a (2.8 g, 0.01 mol) was dissolved in freshly distilled toluene (30 ml) and triethylphosphite (5 g,
1%‘. Zhcm er al. /Syzrhctic
Metals
0.03 mol) ) under argon atmosphere and heated to reflux with stirring for 8 h; the solution became orange. Toluene was distilled off and chromatographic separation of the residue on silica gel (petroleum ether (60-90 “C) :ethyl acetate = 2: 1 vol./vol.) gave 3a as an orange solid (2.1 g, 7.7 mmol); yield 77%; melting point 90-91 ‘C. ‘H NMR (CDC13) 6 (ppm): 2.05 (s, 6H), 3.18 (m, 4H), 3.85 (m, 2H),4.30 (d, 4H). MS (EI) in/z: 528 (M’, lOO%), 428 (52%), 308(28%),265(20%).A&.Found: C,36.66;H, 3.08.Calc. for C,,H,,O&: C, 36.36; H, 3.03%. 3.5. Bis-aceto~~ropanyl-substitzrted4,5-ethylenedithiol-TF (3b) The same procedures as in the previous sections were used. The product is a red oil; yield 75% (for Method C) . ‘H NMR (CDCl,) 6 (ppm): 1.85 (m, 8H), 2.10 (s, 6H), 3.05 (m, 2H), 3.30 (m, 2H), 3.58 (t, 2H), 4.10 (t, 4H). MS (EI) m/ z: 584 (M’, lOO%), 456 (40%), 336 (38%), 292 (24%). And. Found: C, 41.26; H, 4.26. Calc. for COHZJO&: C, 41.10; H, 4.21%. 3.6. Bis-hydro~r~lethylene-srlbstitlrted4,5-etl~~lenenithioTTF (4a) Method A: T‘TF 3a ( 1 g, 1.9 mmol) was dissolved in a mixture of chloroform (20 ml) and methanol ( 60 ml) ; potassium hydroxide (0.85 g, 15 mmol) was added and the solution was heated to reflux for 8 h. Solvent was evaporated off and water ( 100 ml) was added, the solid was filtered, washed with a large amount of water and a small amount of methanol to give a light yellow solid of 4a (0.8 g, 1.8 mmol); yield 94%; melting point 168-169 “C. Method B: TTF 3a (1 g, 1.9 mmol) was dissolved in a mixture of chloroform (20 ml) and methanol (60 ml) ; hydrazinc hydrate ( 1.5 g, 30 mmol) was added and the solution was stirred at room temperature for 24 h. The same workup as Method A gave a yellow solid of 4a (0.8 g, 1.8 mmol); yield 94%; melting point 168-169 “C. ‘H NMR ( CD,COCD3) 6 (ppm) : 3.40 (m, 2H), 3.68 (m,
&Hjm;3.76
S5(1997)
93
91-93
(m, 4H). EI-Mass /U/Z: 444 (M+, 17%), 386 (17%), 243 (28%), 178 ( 100%). Annl. Found: C, 32.93; H, 2.88. Calc. for C,,H,,O,S&: C, 32.46; H, 2.70%. 3.7. Bis-ll~~ro~I,ro~~anvl-sllbstitllted TTF (4b)
4,.5-ethylenedithio-
This was prepared by Method A. The product is a redbrown solid; yield 95%; melting point 75-76 “C!. ‘H NMR (CDCl,) 6 (ppm): 1.80 (m, 8H), 3.10 (m, 2H), 3.22 (m, 2H), 3.58 (m, 2H), 3.70 (t, 4H). EI-Mass m/z: 500 (M’, 100%)) 414 (40%)) 294 (34%). Anal. Found: C, 38.33; H, 3.71. Calc. for C,bH2002S8: C, 38.40; H, 4.00%.
Acknowledgements Project 29574156 is supported by the National Natural Science Foundation of China and the Foundation of the Open Laboratory of Organic Solids, Chinese Academy of Science.
References [ 11 (a) A. Otsuka, H. Yamochi, G. Saito, T. Sugano, M. Kinoshita, S. Sato, K. Honda, K. Ohfuchi and M. Konno, Sprh. Mer., 4143 ( 1991) 1699; (b) M. Adam and K. Muellen, At/l. ;ilorer., 6 (1991) 439; (c) T. Otsubo, T. Aso and K. Takimiya. &it,. Mare):, S ( 1996) 203; (d) A. Mhanni, L. Ouahab, 0. Peda and D. Grandjean, Sprh. Mer., 41-43 (1991) 1703. [2] M.L. Khidekel and E.I. Zhilyaeva, Sprir. iller., 4 ( 1981) 1. [3] (a) Cl. Saito and S. Kahoshima. Tiie Phpics clnci Citentisrry of0rpwic Superrorductors, Springer Proceedings in Physics, Vol. 5 1, Springer, Berlin, 1990; (b) V.Z. Kresin and W.A. Little, Organic &percomf~~cti~i~. Plenum, New York, 1990. [4] (a) T. Inoue. H. Yamochi, G. Saito and K. Mutdumoto, SJW/~. Mrr., 70 (1995) 1139; (b) M. Jorgenben,‘K. Bechgaad, T. Bjornholim, P.S. Larsen, L.G. Hansen and K. Schaumburg, J. Org. Chem., 59 (1991) 5877: (c) MR. Bryce, G. Cooke, A.S. Dhindsa, D. Lorcy, A.J. Moore, M.C. Petty, M.B. Hursthouse and A.J. Knraulov, J. C/wit. Sot., Clie/x Cornr~w~., ( 1990) 516; (d) J.M. Fabre, J. Gartin and S. Uriel, Terrclhedron Mr., 32 ( 1991) 685. [5] W.-G. Zhao, Y.-J. Shen and H.L.D: Xuebao, in press.
Synthetic
Metals 89 ( 1997) 91-93
Synthesis of hydroxyalkyl-substituted bis (ethylenedithio) -tetrathiafulvalene derivatives Weiguo Zhao a, Yongjia Shen a3*, Yongfang Li b, Jing Yang b a Institute of Fine Chemicals, East China lJni\aersio h Laboratory of Organic Solids, lmtitute ojChemist>):
of Science rind Technology, Shanghai 200237, China Chinese Academy ojScience, Beijing 100080, Chinci
Received 8 September 1996; accepted 22 April 1997
Abstract Four substituted bis( ethylenedithio)-tetrathiafulvalene (BEDT-TTF) derivatives were synthesized, and their MS and NMR spectra are given. The redox properties of the compounds were studied by cyclic voltammetry. The powder conductivities of the charge-transfercomplexes of the hydroxyalkyl-substituted BEDT-TTF with TCNQ were measured by two-probe contacts. The results show that they are semiconductors. 0 1997 Elsevier Science S.A. Ke>wjords:
Tetrathiafulvalene; Charge-transfer complexes
I. Introduction
CH,COOR
Much effort is still being devoted to improving the electrical properties of radical-cation salts of tetrathiafulvalene (TTF) derivatives [ 11. It is well known that most synthetic metalshave Peierlsdistortion [ 21. Increasingtheir dimension by modifying the TTF framework can stabilize their metallic state (by suppressingPeierlsdistortion) leading to superconductivity at low temperatures[ 31. Therefore, functional TTF derivatives have received much attention [ 41. Recently, we synthesized two new bis( ethylenedithio)tetrathiafulvalene (BEDT-TTF) derivatives (4a and 4b) containing two hydroxyl substituents.Such derivatives are suitable precursors and building blocks, which can further react with acids, anhydrides, halogen compounds,or polymerize with diacids or the correspondingacid chlorides.The synthetic route is shown in Scheme1.
2. Results and discussion The self-coupling reactionsof both thione la-b and ketone 2a-b in triethylphosphite or in a mixture of triethylphosphite and toluene as solvents are successful,only the yields of compound 3 formed are different. The yield starting from ketone 2 is higher than that starting from thione 1. However, compound 3 is not formed if the reaction is carried out in a * Corresponding author. 0379-6779/97/$17.00 PZlSO379-6779(97)03880-O
0 1997 Elsevier Science S.A. All rights reserved
Hg(CH$OO),
CH,COO
(EtOhP/
MeOH
-
la-b
3a-b
KOH
-““‘-f&&&ROH
4
a:R
q
CHZ
b:R
q
C3H,j
Scheme 1.
mixlure of tnethylphosphite andbenzeneassolvents.Perhaps the reaction temperatureis too low, becausethe boiling point of benzene is lower than toluene. The reaction should be carried out under the protection of argon. A red by-product will be formed without the protection of argon. It is very difficult to remove the by-product from the products 3a or 3b. The non-protected hydroxyl group is too reactive in this self-coupling reaction; it reacts with triethylphosphite and causes triethylphosphite to be hydrolyzed. Hence, the hydroxyl group in la-b and 2a-b must be protected, otherwise only a small amount of the target products will be formed. An acetyl group is a suitableprotection group in such reactions. The experiments show that the acetyl group is effective, due to its easy reaction with the hydroxyl group
92 Table 1 Oxidation
11’. Zhno PI ~1. /Spthrtic
potentiais
’ of the compounds
Compound
.Ey
BEDT-TTF 3a 3b 4a 4b
0.54 0.53 0.49 0.47 0.37
(V)
3a-b, E:”
BE”?
0.96 0.92 0.82 0.87 0.85
in CH,CI,,
and removal after the coupling reaction. Two methods can be used to deprotect the acetyl group: one is to alcoholize it with potassium hydroxide in methanol and the other is to reduce it with hydrazine hydrate. Potassium hydroxide in methanol is an efficient alcoholysis reagent to cleave the acetyl group in 3a and 3b; however, hydrazine hydrate is only able to cleave the acetyl group in 3a. Both deprotection reactions are nearly quantitative. The solution redox chemistry of the new TTF derivatives has been studied by cyclic voltammetry. Each donor shows two single electron and reversible redox waves at the expected potentials for TTF derivatives. Their data together with 3EDT-TTF are shown in Table 1. The data in Table 1 show that the reversible redox values of the new TTF derivatives are lower than BEDT-TTF. Therefore, the four derivatives can be considered as promising candidates for organic conductors. 3a and 3b are less easily oxidized than 4a and 4b, presumably because of the electron-withdrawing effect of two ester groups in 3a and 3b. With the extension of the carbon chain, the electron-withdrawing effect of the ester group attenuated quickly, so the value of 3b is similar to that of 4b. The charge-transfer (CT) complexes of four new TTF derivatives with tetracyanoquinodimethane (TCNQ) were obtained by mixing them in hot dichlorobenzene. The conductivities (a) of the pressed pellets of the powdery CT complexes measured by the two-probe technique are shown in Table 2; they are all semiconductors. Attempts to grow crystals by electrocrystallization with Bu,NPF, or Bu,NC104 were unsuccessful; no high quality single crystals were obtained.
3. Experimental 3.1. Aceio~~merhq!lene-sllbstiruren 4,S-erhylerzediti’?ioI,3-dithiole-2-thione (la) and acetoqpropanyl-substituted 4,5-ethplerzedithio-l,3-dithiole-2-thione (Ib)
The general method for the synthesis Ref. [ 51 has been used.
91-93
(a)
of the CT complexes
of the compounds
(3a-b,
(V)
0.42 0.39 0.33 0.40 0.38
a Conditions: Pt electrode, 25 “C, under argon, 0.1 M Bu,NPF, SCE as the reference electrode, scan rate 5 mV s - I.
89 (1997)
Table 2 Powder conductivity 4a-b) with TCNQ
4a-b and BEDT-TTF (V)
Met&
as described in
Compound
v (S cm-‘)
3a 3b 4a 4b
3.18X 1.32x 5.65 x 7.19x
3.2. Acetonymethylene-substituted 1,3-dithiole-2-one (2aj
10-x io-F IO-” 10-l
4,5-eth~lerledirhio-
Thione la (3 g, 0.0 1 mol) was dissolved in a mixture of chloroform (20 ml) and acetic acid (20 ml) ; mercury acetate (9.6 g, 0.03 mol) was added to this solurion. The reaction mixture was stirred at room temperature for 4 h. The white precipitate which formed was filtered off, the filtrate was washed with water, 5% solution of sodium bicarbonate and finally water, and dried with anhydrous sodium sulfate. Solvent was evaporated to yield a light yellow solid (2.6 g, 9.5 mmol); yield 95%; melting point 3X-49 “C. ‘H NMR (CDCI,) 6 (ppm): 2.10 (s, 3H), 3.40 (II-I, 2H), 4.15 (m, IH), 4.40 (d, 2H). MS (EI) m/z: 280 (M+, lOO%), 220 ( 13%). Anal. Found: C, 34.73; H, 3.24. Calc. for C,HBO,S,: C, 34.29; H, 2.86%. 3.3. Acetos?lpropan~ll-srlbstitl{ted I,3-dithiole-2- rhione (2b)
4,5-etl~~ienedit~lio-
The synthesis was the same as in the previous section. The product is a light yellow oil; yield 95%. ‘1-I NMR ( CDCl,) 6 (ppm): 1.85 (m, 4H), 2.15 (s, 3H), 3.18 (m, lH), 3.42 (m, IH), 3.68 (m, 1H), 4.10 (m, 2H). MS (EI) m/z: 308 (M+, 80%), 248 (100%). Aunl. Found: C, 38.61; H, 3.99. Calc. for C10H,203S-I: C, 38.96; H, 3.90%. 3.4. Bis-aceto~~~nethgIene-substitL~tcd4,5-etlzyIenedithioTTF (3a) Method A: Thione la (3.0 g, 0.01 mol) was dissolved in freshly distilled triethylphosphite (20 ml) under argon atmosphere and heated to 1lo-120 “C with stirring for 4 h; the solution became orange. Removal of triethylphosphite under reduced pressure and chromatographic separation of the residue on silica gel (petroleum ether (60-90 “C) :ethyl acetate=2:1 vol./vol.) gave 3a as an orange solid (0.9 g, 3.4 mmol); yield 34%; melting point 90-91 “C. Method B: Ketone 2a (2.8 g, 0.01 mol) was dissolved in freshly distilled triethylphosphite (20 ml) under argon atmosphere and heated to 1 lo-120 “C with stirring for 4 h; the solution became orange. The same workup as Method A gave 3a as an orange solid (2.0 g, 7.5 mmol); yield 75%; melting point 90-9 1 “C. Method C: Ketone 2a (2.8 g, 0.01 mol) was dissolved in freshly distilled toluene (30 ml) and triethylphosphite (5 g,
1%‘. Zhcm er al. /Syzrhctic
Metals
0.03 mol) ) under argon atmosphere and heated to reflux with stirring for 8 h; the solution became orange. Toluene was distilled off and chromatographic separation of the residue on silica gel (petroleum ether (60-90 “C) :ethyl acetate = 2: 1 vol./vol.) gave 3a as an orange solid (2.1 g, 7.7 mmol); yield 77%; melting point 90-91 ‘C. ‘H NMR (CDC13) 6 (ppm): 2.05 (s, 6H), 3.18 (m, 4H), 3.85 (m, 2H),4.30 (d, 4H). MS (EI) in/z: 528 (M’, lOO%), 428 (52%), 308(28%),265(20%).A&.Found: C,36.66;H, 3.08.Calc. for C,,H,,O&: C, 36.36; H, 3.03%. 3.5. Bis-aceto~~ropanyl-substitzrted4,5-ethylenedithiol-TF (3b) The same procedures as in the previous sections were used. The product is a red oil; yield 75% (for Method C) . ‘H NMR (CDCl,) 6 (ppm): 1.85 (m, 8H), 2.10 (s, 6H), 3.05 (m, 2H), 3.30 (m, 2H), 3.58 (t, 2H), 4.10 (t, 4H). MS (EI) m/ z: 584 (M’, lOO%), 456 (40%), 336 (38%), 292 (24%). And. Found: C, 41.26; H, 4.26. Calc. for COHZJO&: C, 41.10; H, 4.21%. 3.6. Bis-hydro~r~lethylene-srlbstitlrted4,5-etl~~lenenithioTTF (4a) Method A: T‘TF 3a ( 1 g, 1.9 mmol) was dissolved in a mixture of chloroform (20 ml) and methanol ( 60 ml) ; potassium hydroxide (0.85 g, 15 mmol) was added and the solution was heated to reflux for 8 h. Solvent was evaporated off and water ( 100 ml) was added, the solid was filtered, washed with a large amount of water and a small amount of methanol to give a light yellow solid of 4a (0.8 g, 1.8 mmol); yield 94%; melting point 168-169 “C. Method B: TTF 3a (1 g, 1.9 mmol) was dissolved in a mixture of chloroform (20 ml) and methanol (60 ml) ; hydrazinc hydrate ( 1.5 g, 30 mmol) was added and the solution was stirred at room temperature for 24 h. The same workup as Method A gave a yellow solid of 4a (0.8 g, 1.8 mmol); yield 94%; melting point 168-169 “C. ‘H NMR ( CD,COCD3) 6 (ppm) : 3.40 (m, 2H), 3.68 (m,
&Hjm;3.76
S5(1997)
93
91-93
(m, 4H). EI-Mass /U/Z: 444 (M+, 17%), 386 (17%), 243 (28%), 178 ( 100%). Annl. Found: C, 32.93; H, 2.88. Calc. for C,,H,,O,S&: C, 32.46; H, 2.70%. 3.7. Bis-ll~~ro~I,ro~~anvl-sllbstitllted TTF (4b)
4,.5-ethylenedithio-
This was prepared by Method A. The product is a redbrown solid; yield 95%; melting point 75-76 “C!. ‘H NMR (CDCl,) 6 (ppm): 1.80 (m, 8H), 3.10 (m, 2H), 3.22 (m, 2H), 3.58 (m, 2H), 3.70 (t, 4H). EI-Mass m/z: 500 (M’, 100%)) 414 (40%)) 294 (34%). Anal. Found: C, 38.33; H, 3.71. Calc. for C,bH2002S8: C, 38.40; H, 4.00%.
Acknowledgements Project 29574156 is supported by the National Natural Science Foundation of China and the Foundation of the Open Laboratory of Organic Solids, Chinese Academy of Science.
References [ 11 (a) A. Otsuka, H. Yamochi, G. Saito, T. Sugano, M. Kinoshita, S. Sato, K. Honda, K. Ohfuchi and M. Konno, Sprh. Mer., 4143 ( 1991) 1699; (b) M. Adam and K. Muellen, At/l. ;ilorer., 6 (1991) 439; (c) T. Otsubo, T. Aso and K. Takimiya. &it,. Mare):, S ( 1996) 203; (d) A. Mhanni, L. Ouahab, 0. Peda and D. Grandjean, Sprh. Mer., 41-43 (1991) 1703. [2] M.L. Khidekel and E.I. Zhilyaeva, Sprir. iller., 4 ( 1981) 1. [3] (a) Cl. Saito and S. Kahoshima. Tiie Phpics clnci Citentisrry of0rpwic Superrorductors, Springer Proceedings in Physics, Vol. 5 1, Springer, Berlin, 1990; (b) V.Z. Kresin and W.A. Little, Organic &percomf~~cti~i~. Plenum, New York, 1990. [4] (a) T. Inoue. H. Yamochi, G. Saito and K. Mutdumoto, SJW/~. Mrr., 70 (1995) 1139; (b) M. Jorgenben,‘K. Bechgaad, T. Bjornholim, P.S. Larsen, L.G. Hansen and K. Schaumburg, J. Org. Chem., 59 (1991) 5877: (c) MR. Bryce, G. Cooke, A.S. Dhindsa, D. Lorcy, A.J. Moore, M.C. Petty, M.B. Hursthouse and A.J. Knraulov, J. C/wit. Sot., Clie/x Cornr~w~., ( 1990) 516; (d) J.M. Fabre, J. Gartin and S. Uriel, Terrclhedron Mr., 32 ( 1991) 685. [5] W.-G. Zhao, Y.-J. Shen and H.L.D: Xuebao, in press.