Synthesis and electrochemical properties of highly extended and sulfur-rich vinylogs of tetrathiafulvalene

Article abstract of DOI:10.1002/1099-0690(200110)2001:19<3741::AID-EJOC3741>3.0.CO;2-0

Using the reactivity of the carbonyl groups of 4,5-diformyl-1,3-dithiol-2-ylidene-substituted ethanals or ethanones with ylides or phosphonate anions, highly extended analogs of TTF 1 and 2 were synthesized by Wittig or Wittig-Horner reactions. Their excellent π-donor properties, as well as the possibility of obtaining polycationic states, were confirmed by cyclic voltammetry. The structural study of cation-radical salt 1bΒγ·PF₆ reveals a two-dimensional network in the solid state.

Full text of DOI:10.1002/1099-0690(200110)2001:19<3741::AID-EJOC3741>3.0.CO;2-0

FULL PAPER
Synthesis and Electrochemical Properties of Highly Extended and Sulfur-Rich
Vinylogs of Tetrathiafulvalene
[a]
[b]
[b]
[b]
[a]
`
Pierre Frere,* Kamal Boubekeur, Michel Jubault, Patrick Batail, and Alain Gorgues*
Keywords: Electrochemistry / Thiafulvalenes
Using the reactivity of the carbonyl groups of 4,5-diformyl-
1,3-dithiol-2-ylidene-substituted ethanals or ethanones with
possibility of obtaining polycationic states, were confirmed
by cyclic voltammetry. The structural study of cation-radical
ylides or phosphonate anions, highly extended analogs of salt 1bβγ·PF6 reveals a two-dimensional network in the
TTF 1 and 2 were synthesized by Wittig or Wittig−Horner
reactions. Their excellent π-donor properties, as well as the
solid state.
Introduction
Owing to their high electrical conductivity and their un-
usual magnetic properties, the cation-radical salts (CRS) of
the tetrathiafulvalene (TTF) series are the subject of consid-
erable works.[1] While physicists and theoreticians aim for a
better understanding and characterization of their physical
behavior, chemists are focusing on improving the properties
of these organic materials by developing new structures.[2,3]
A lot of time has been invested in the design of new π-
donors by modification of the TTF framework in order to
increase the stability of the cation radical and/or to control
the intermolecular architecture in the material.[4] The main
objective is to enhance the dimensionality in the solid state
in order to suppress the Peierls transition resulting from
electronϪphonon coupling inherent to monodimensional
materials. A trend in this area involves the building of
highly extended and sulfur-rich π-donors.[5] For the molec-
ule, a better stability of oxidized states is expected due to
the larger delocalization of the positive charge in the cation
radical and the weaker intramolecular coulombic repulsion
in the polycationic states.[6] Moreover, both the increase in
the π-interactions and sulfurϪsulfur contacts may allow
better intra- and inter-chain contacts between the donors,
and may increase the dimensionality of the corresponding
CRS. Based on these considerations, our group has shown
Scheme 1
behavior of molecules 1 and their precursors, 2 are de-
scribed (Scheme 1), as well as the structure of a cation rad-
ical salt derived from 1.
that extended tetrathiafulvalenes built from a TTF core Results and Discussion
bearing 1,4-dithiafulven-6-yl groups as substituents leads to
an original material with a significant 2D character.[7] Mori
The retrosynthetic strategy involves a triple Wittig or
and Misaki have equally obtained a new superconducting
CRS from a fused TTF with an ethylenic spacer.[8] Com-
pounds 1 combine these two approaches[9] by possessing a
TTF vinylog framework grafted with two dithiafulvene
arms. In this article, the synthesis and the electrochemical
WittigϪHorner olefination from 4,5-diformyl-1,3-dithiol-2-
ylidene-substituted ethanals or ethanones 3 with Akiba’s re-
agents W or P, bearing the adequately 4,5-disubstituted 1,3-
dithiol-2-ylidene moiety (Scheme 2).[10] Compounds 3 with
varied substituents R1 and R2 are obtained from the mono-
(diethyl) acetal of acetylenedicarbaldehyde and a 3-thioxo-
1,2-dithiole as previously described.[11]
Several attempts to obtain 1 directly from 3 and phos-
phorus ylides W, which are easier to handle than corres-
ponding phosphonates anions P, were unsuccessful. These
reaction always stopped at the stage of bis(olefination) of
[a]
´
´
´
Ingenierie Moleculaire et Materiaux Organiques, UMR 6501
´
CNRS, Universite d’Angers,
2 Bd. Lavoisier, 49045 Angers, France
E-mail: pierre.frere@univ-angers.fr
[b]
´
Laboratoire Sciences Moleculaires aux Interfaces, FRE CNRS
2068,
`
2 rue de la Houssiniere, 44322 Nantes cedex 03, France
Eur. J. Org. Chem. 2001, 3741Ϫ3747
WILEY-VCH Verlag GmbH, 69451 Weinheim, 2001
1434Ϫ193X/01/1019Ϫ3741 $ 17.50ϩ.50/0
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P. Frere, K. Boubekeur, M. Jubault, P. Batail, A. Gorgues
FULL PAPER
Scheme 4
strongly releasing dithiafulvalenyl groups grafted in the 4,5-
positions of the dithiole ring confers an additional import-
ance to the poorly reactive form B. Additionally, we should
keep in mind that compounds 3 present a δ-cis conforma-
tion, stabilized by a strong S···O intramolecular interac-
tion,[12] which contributes to enhance the activation energy
of the olefination reaction.
Except in the case of the aromatic ketone 2d (R2 ϭ Ar),
the olefination of compounds 2 could be carried out by
using an excess (2 equiv.) of the more nucleophilic anion P.
This anion was generated from the corresponding phos-
phonate by treatment with BuLi in the presence of the car-
bonyl compound 2 at 0Ϫ10 °C. This unconventional pro-
cedure was also effective starting from 3 by adding 4 equiv.
of P, thus giving rise directly to 1 in one step. As indicated
in Scheme 3, playing with the various reactivity of the car-
bonyl groups of compounds 3 with Akiba’s reagents W and
Scheme 2
the vicinal aldehyde functionalities, thus leading to com- P, we have synthesized several products 1 that are substi-
pounds 2 (Scheme 3), even in the presence of a very large tuted with different (from 2) or identical groups R and RЈ.
excess of W. This failure can be explained by both electronic The procedure, the yield, and the numeration adopted for
and structural effects that contribute to a decrease in the the compounds 1 and 2 synthesized are summarized in
reactivity of the remaining carbonyl group. As shown in Table 1.
Scheme 4, the weight of the mesomeric form B, which de-
All these new donors undergo the acid-mediated intram-
creases the electrophilicity of this carbonyl group, is en- olecular cyclization shown in Scheme 5.[12] For compounds
hanced by the aromatic character of the dithiolium cation. 1, 2aδ, and 2bδ, this reaction was very fast, and only a trace
Moreover, in the case of compounds 2, the presence of the of acid was sufficient to provoke the cyclization. Thus, as
Scheme 3
3742
Eur. J. Org. Chem. 2001, 3741Ϫ3747

Highly Extended and Sulfur-Rich Vinylogs of Tetrathiafulvalene
FULL PAPER
Table 1. Names and yields of compounds 1 and 2
Starting material
R1
R2
Akiba’s reagent
Name
R or RϪR
RЈ or RЈϪRЈ
Yield
3a
Ph
H
H
Ph
H
H
Me
Me
H
H
H
H
H
Me
H
H
Wα
Wα
Wα
Wβ
Wβ
Wβ
Wγ
Wδ
Wδ
Pβ
2aα
2bα
2dα
2aβ
CO2Me
CO2Me
CO2Me
Ϫ(CHϭCH)2Ϫ
Ϫ(CHϭCH)2Ϫ
Ϫ(CHϭCH)2Ϫ
ϪSCH2ϪCH2SϪ
Ϫ(CH2)4Ϫ
Ϫ
Ϫ
Ϫ
Ϫ
Ϫ
Ϫ
Ϫ
Ϫ
73%
81%
90%
89%
93%
91%
83%
91%
91%
80%
70%
85%
73%
84%
85%
3b
p-Me-C6H4
H
Ph
p-Me-C6H4
Me
Me
3d
3a
3b
2bβ
3c
2cβ
3c
2cγ
3a
Ph
2aδ
3b
p-Me-C6H4
Ph
p-Me-C6H4
p-Me-C6H4
Me
2bδ
Ϫ(CH2)4Ϫ
Ϫ
3a
1aββ
1bββ
1bβγ
1cβγ
1aδβ
1bδγ
Ϫ(CHϭCH)2Ϫ
Ϫ(CHϭCH)2Ϫ
Ϫ(CHϭCH)2Ϫ
Ϫ(CHϭCH)2Ϫ
Ϫ(CH2)4Ϫ
Ϫ(CHϭCH)2Ϫ
Ϫ(CHϭCH)2Ϫ
ϪSCH2ϪCH2SϪ
ϪSCH2ϪCH2SϪ
Ϫ(CHϭCH)2Ϫ
ϪSCH2ϪCH2SϪ
3b
Pβ
2bβ
2cβ
2aδ
2bδ
Pγ
Pγ
Ph
Pβ
p-Me-C6H4
Pγ
Ϫ(CH2)4Ϫ
The π-donor ability of compounds 1 and 2 was evaluated
using cyclic voltammetry (CV) in dichloromethane as the
solvent, previously filtered on a column of basic alumina.
The CVs of compounds 2 exhibit two reversible one-elec-
tron waves with peak potentials Epa1 and Epa2 correspond-
ing to the successive generation of the cation radical and
dication, respectively. A comparison of the CV data col-
lected in Table 2 shows that for a given R substituent on
the dithiafulvalenyl moieties, the nature of the R1 and R2
groups exerts a weak influence on the Epa1 and Epa2 values
only, while the electron donor effect of R strongly affects
the π-donor character of compounds 2. Thus, the replace-
ment of the electron-withdrawing CO2Me group by the
Scheme 5
Table 2. Cyclic voltammetric data for compounds 2; conditions:
Bu4NPF6 0.1  in CH2Cl2, scan rate v ϭ 100 mV sϪ1, vs. SCE
Figure 1. 1H NMR spectra of 2bδ: Ϫ in CS2 ϩ C6D6 (top); Ϫ after
5 min in CDCl3 (bottom)
1
shown in Figure 1, the H NMR spectrum of 2bδ executed
in CDCl3, compared to one performed in a mixture of CS2
and C6D6 led, after only 5 min, to a replacement of the
ethylenic proton signals at δ ϭ 6.5 by two singlets at δ ϭ
3.8 and δ ϭ 3.9, corresponding to the cyclized form of 2bδ.
For compounds 1, the cyclizations were accompanied by
the degradation of the molecules. In addition, the com-
pounds are very thermally labile and light-sensitive, so they
had to be stored in the dark at Ϫ20 °C.
Eur. J. Org. Chem. 2001, 3741Ϫ3747
3743

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P. Frere, K. Boubekeur, M. Jubault, P. Batail, A. Gorgues
FULL PAPER
electron releasing Ϫ(CH2)4Ϫ group produces a negative other hand, the large extension of the molecules and the
shift of Epa1 values from 0.7 to 0.3 V. As shown in Table 2, multiplication of the dithiafulvalenyl substituents allow to
the oxidation potentials of TTF derivatives TTFα and reach multicationic states, such as a trication radical and a
TTFβ are superior to those of compounds 2 bearing the tetracation. The electrochemical properties mainly depend
same substituents R, while the vinylogs of tetrathiafulvalene on the nature of the substituents R. In the presence of the
V-TTFα and V-TTFβ present similar values.[13] In particu- most electron-donating Ϫ(CH2)4Ϫ groups, the Epa1 reaches
lar, the weak difference ∆E ϭ Epa2 Ϫ Epa1, is close to ca. a value as low as 0.06 V for 1bδγ, which is among the lowest
0.14V for compounds 2 compared to the parent TTF known in the TTF series.[14] The comparison between the
(about 0.3 V). This indicates a reduced intramolecular cou- data obtained for 1bβγ and 1cβγ, which differ in the R1 and
lombic repulsion between the positive charges in the dicat- R2 groups, shows a shift to a more positive potential of
ion as in the case of V-TTF. Hence, despite the presence of 0.12V for 1cβγ. This result suggests a decrease in the con-
electron-withdrawing carbonyl group, compounds 2 present jugation for 1cβγ owing to the distortion of the ethylenic
a better π-donor ability than TTF core and nearly reach the spacers caused by steric hindrance between the close Me
electrochemical behavior of V-TTF.
substituents.
The CVs of compounds 1 show three reversible one-elec-
tron oxidation waves followed by an irreversible one (Fig-
ure 2). Table 3 lists the values of the redox potentials (Epa1,
Epa2, Epa3, Epa4) corresponding to the generation of the
various cationic species. As expected, replacing the carbonyl
group in 2 by the strongly electron-releasing dithiafulvalene
group dramatically increased the π-donor character of com-
pounds 1. Thus the Epa2 values of 1aββ and 1bββ corres-
Compounds 1aββ, 1bββ, and 1bβγ give small dark crys-
tals by electrocrystallization under galvanostatic conditions
in the presence of Bu4NPF6 or Bu4NClO4 in CH2Cl2.
Although the poor quality of the crystals, the 1:1 stoichio-
metry and the structure of the cation radical salt namely
1bβγ·PF6 was determined from X-ray diffraction.
As shown in Figure 3, the cation radical is characterized
by the plane formed by the four dithiole rings, while the p-
Me-C6H4 unit is located in a perpendicular plane. The two
vicinal dithiafulvenyl arms and the central dithiole cycle
present strong S···S intramolecular interactions character-
ponding to the formation of the dication 1
are inferior
to the first oxidation potential Epa1 of V-TTFβ. On the
˚
˚
ized by the short distances d ϭ 2.95 A and dЈ ϭ 2.98 A.
Such nonbonding 1Ϫ5 interactions between sulfur atoms of
a dithiafulvene cycle and a central heterocycle have already
been observed for neutral and cation radical states, allowing
the planar conformation to be maintained during the oxida-
tion process.[7,15]
As shown in Figure 4, the structure of 1bβγ·PF6 is built
up from sheets of molecules stacked along the OϪA axis
with an inclination of 22°. Intermolecular contacts (d1 ϭ
˚
3.54 A) between cations in the same layer are observed. The
overlap mode, where a cation bridges the two others, min-
imizes the steric hindrance between bulky aryl units, and
allows several close contacts between the neighboring
donors. The distance between the planes in the stacking is
Figure 2. Cyclic voltammogram of compound 1bδγ (ca. 10Ϫ4 mol
Ϫ1) in 10Ϫ1 mol LϪ1 Bu4NPF6/CH2Cl2, scan rate 100 mV·sϪ1 vs.
SCE
L
˚
about 3.6 A.
Table 3. Cyclic voltammetric data for compounds 1; conditions: Bu4NPF6 0.1  in CH2Cl2, scan rate v ϭ 100 mVsϪ1, vs. SCE
Compound
1aββ
R1 and R2
RϪR and RЈϪRЈ
Epa1 [V]
0.25
Epa2 [V]
0.44
Epa3 [V]
1.07
Epa4 [V]
1.4 0
1.40
R1 ϭ Ph
RϪR ϭ Ϫ(CHϭCH)2Ϫ
RЈϪRЈ ϭ Ϫ(CHϭCH)2Ϫ
RϪR ϭ Ϫ(CHϭCH)2Ϫ
RЈϪRЈ ϭ Ϫ(CHϭCH)2Ϫ
RϪR ϭ Ϫ(CHϭCH)2Ϫ
RЈϪRЈ ϭ ϪSCH2ϪCH2SϪ
RϪR ϭ Ϫ(CHϭCH)2ϪRЈϪRЈ ϭ ϪSCH2ϪCH2SϪ
R2 ϭ H
1bββ
R1 ϭ p-Me-C6H4
R2 ϭ H
0.23
0.43
1.10
1bβγ
R1 ϭ p-Me-C6H4
R2 ϭ H
0.22
0.39
1.03
1.37
1cβγ
R1 ϭ Me
0.34
0.50
1.10
1.40
R2 ϭ Me
1aδβ
R1 ϭ Ph
RϪR ϭ Ϫ(CH2)4Ϫ
RЈϪRЈ ϭ Ϫ(CHϭCH)2Ϫ
RϪR ϭ Ϫ(CH2)4Ϫ
RЈϪRЈ ϭ Ϫ(CHϭCH)2Ϫ
RϪR ϭ Ϫ(CH2)4Ϫ
RЈϪRЈ ϭ ϪSCH2ϪCH2SϪ
0.12
0.30
0.94
1.30
R2 ϭ H
1bδβ
R1 ϭ p-Me-C6H4
R2 ϭ H
0.10
0.27
0.93
1.29
1bδγ
R1 ϭ p-Me-C6H4
R2 ϭ H
0.06
0.23
0.85
1.26
3744
Eur. J. Org. Chem. 2001, 3741Ϫ3747

Highly Extended and Sulfur-Rich Vinylogs of Tetrathiafulvalene
FULL PAPER
·
Figure 3. X-ray crystal structure of cation radical 1bβγ
Figure 4. Overlap mode and close contacts of cation radicals in the salt 1bβγ·PF6
The conductivity measurements performed on powders metry have already been observed for CRS of extended
of different salts gave values of ca. 10Ϫ1 S·cmϪ1. Rela- donors and are ascribed to decreasing coulombic repul-
tively high conductivity obtained for salts of 1:1 stoichio- sion.[7,14,16]
Eur. J. Org. Chem. 2001, 3741Ϫ3747
3745

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P. Frere, K. Boubekeur, M. Jubault, P. Batail, A. Gorgues
FULL PAPER
(s, 1 H), 3.90Ϫ3.83Ϫ3.81 (3 s, 12 H). Ϫ C27H20O9S6: calcd.
679.94316 for [Mϩ], found 679.9402. Ϫ Elemental analysis: calcd.
C 47.63, H 2.96, O 21.15, S 28.25; found C 47.53, H 3.11, O 20.97,
S 26.80.
Conclusion
In conclusion, a new series of highly extended analogs of
TTF 1 has been synthesized in one or two steps, using the
difference in reactivity of ylides and phosphonate anions
for the olefination of different carbonyl functionalities in
compounds 3. Their electrochemical properties reveal an
Olefination with Ylide Wβ, γ, δ: A dry THF solution containing
the phosphonium salt (2 mmol), cooled to Ϫ78 °C under nitrogen,
was treated dropwise with 1.24 mL of a 1.6  BuLi in hexane solu-
exceptional π-donor ability associated to an access to polyc- tion. The yellow solution of Wβ, γ, δ was stirred for 10 min and
0.9 mmol of the tricarbonyl compound 3, diluted in dry THF, was
introduced dropwise at Ϫ78 °C. A brown precipitate appeared and
the reaction mixture was allowed to warm to room temp. and con-
centrated in vacuo. The crude material was filtered off and washed
with methanol, acetonitrile, and diethyl ether. The red powders
were recrystallized from THF solutions.
ationic states. In agreement with previous works, the cation
radical salt obtained with a compound 1 confirms the ra-
tional approach in the design of extended- and sulfur-rich
donors in order to enhance the dimensionality in the mat-
erials.
2aβ [R1
Ph, R2
H, R
R
(CH CH)2 ]: M.p. 248 °C
(dec.). Ϫ 1H NMR (CS2 ϩ C6D6): δ ϭ 9.13 (s, 1 H), 7.22Ϫ6.84 (m,
5 H), 6.11 (s, 1 H), 6.08 (s, 1 H). Ϫ C27H16OS6: calcd. 547.95254 for
[Mϩ], found 547.9527. Ϫ Elemental analysis: calcd. C 59.09, H
2.94; found C 59.10, H 3.13.
Experimental Section
1
General: H NMR spectra were recorded with a Jeol GSX270WB
spectrometer, operating at 270 MHz, and 13C NMR with the same
apparatus at 67.5 MHz; δ values are given in ppm (relative to TMS)
and coupling constants in Hz. Ϫ Mass spectra were recorded under
EI or FAB mode either with a Varian MAT 311 in the CRMPO
(Rennes, France) or with a VG Autospec (Zaragoza, Spain). Ϫ
Infrared spectra were recorded with a PerkinϪElmer 841 spectro-
meter. Ϫ Elemental analyses were performed by the service central
d’analyse du CNRS (Vernaison, France).
2aδ [R1
Ph, R2
H, R
R
(CH2)4 ]: M.p. 248 °C (dec.).
Ϫ 1H NMR (CS2 ϩ C6D6): δ ϭ 9.14 (s, 1 H), 7.18Ϫ6.85 (m, 5 H),
6.03 (s, 1 H), 6.01 (s, 1 H), 2.03 (m, 8 H), 1.56 (m, 8 H). Ϫ
C27H24OS6: calcd. 556.0154 for [Mϩ], found 556.013. Ϫ Elemental
analysis: calcd. C 58.23, H 4.34, O 2.87, S 34.55; found C 58.18, H
4.34, O 2.16, S 33.34.
2bβ [R1 p-Me-C6H4, R2 H, R
R
(CH CH)2 ]: M.p. 210
Synthesis of Compounds 2: The ylides W were generated with a base
(Et3N at room temp. for Wα and BuLi at low temperature for
Wβ,γ,δ) from the corresponding phosphonium salts, which were
prepared according to literature procedures.[10]
°C (dec.). Ϫ 1H NMR (CS2 ϩ C6D6): δ ϭ 9.23 (s, 1 H), 7.23Ϫ6.97
(m, 12 H), 6.24 (s, 1 H), 6.22 (s, 1 H), 2.35 (s, 3 H). Ϫ 13C NMR
(CS2 ϩ C6D6): δ ϭ 182.04, 156.81, 139.33, 138.31, 137.59, 137.39,
135.77, 135.70, 134.95, 131.25, 130.24, 128.77, 126.41, 126.33,
126.19, 126.12, 122.33, 122.11, 121.41, 121.32, 121.11, 121.05,
21.88. Ϫ C28H18OS6: calcd. 561.96819 for [Mϩ], found 561.9677.
Olefination with Ylide Wα: A dry THF/CH3CN (30 mL/10 mL) so-
lution containing the phosphonium salt (5 mmol) and the tri-
carbonyl compounds 3 (2 mmol) under nitrogen was treated drop-
wise with triethylamine (1 mL) at room temp., and a brown precip-
itate appeared immediately. The reaction mixture was stirred at
room temp. for 30 min and the solvent was evaporated in vacuo.
The precipitate was filtered off and washed with methanol, aceton-
itrile, and diethyl ether. The brown powders were recrystallized
from a THF solution.
2bδ [R1 p-Me-C6H4, R2 H, R
R
(CH2)4 ]: M.p. 210 °C
(dec.). Ϫ 1H NMR (CS2 ϩ C6D6): δ ϭ 9.15 (s, 1 H), 7.15 (m, 4
H), 6.13 (s, 1 H), 6.10 (s, 1 H), 2.35 (s, 3 H) 2.18 (m, 8 H), 1.68
(m, 8 H). Ϫ FAB MS: m/z ϭ 570 [M]. Ϫ C28H26OS6 (570.9): calcd.
C 58.91, H 4.59, O 2.80, S 33.70; found C 58.55, H 4.54, O 3.25,
S 32.50.
2aα (R1
Ph, R2
H, R
CO2Me): M.p. 130Ϫ131 °C. Ϫ IR
2cβ [R1
Me, R2
Me, R
R
(CH CH)2 ]: M.p. 244 °C
1
1
(CHCl3): ν ϭ 1735, 1620 cm 1. Ϫ H NMR (CDCl3): δ ϭ 9.59 (s, (dec.). Ϫ H NMR (CS2 ϩ C6D6): δ ϭ 7.11Ϫ6.98 (m, 8 H), 6.23
˜
1
H), 7.57 (m, 5 H), 6.28 (s, 1 H), 6.22 (s, 1 H), (s, 1 H), 6.20 (s, 1 H), 2.15 (s, 3 H) 2.10 (s, 3 H). Ϫ C23H16OS6:
3.95Ϫ3.94Ϫ3.91Ϫ3.89 (4 s, 12 H). Ϫ 13C NMR (CDCl3): δ ϭ calcd. 499.9525 for [Mϩ], found 499.9501.
183.96, 159.65, 159.56, 159.52, 159.49, 157.50, 138.18, 137.93,
137.44, 134.16, 130.68, 130.07, 131.17, 128.32, 124.33, 121.83,
2cγ [R1 Me, R2 Me, R
°C (dec.). Ϫ H NMR (CS2 ϩ C6D6): δ ϭ 6.13 (s, 1 H), 6.10 (s, 1
H), 3.24 (s, 8 H) 2.15 (s, 3 H), 2.08 (s, 3 H). Ϫ C19H16OS10 (581.2):
calcd. C 39.15, H 2.76; found C 39.65, H 3.10.
R
S CH2 CH2 S ]: M.p. 250
1
104.82, 104.20, 53.57, 53.53, 21.40.
Ϫ C27H20O9S6: calcd.
679.94316 for [Mϩ], found 679.9416. Ϫ Elemental analysis: calcd.
C 47.63, H 2.96, O 21.15, S 28.25; found C 47.89, H 3.07, O 21.34,
S 28.00.
Synthesis of Compounds 1: A suspension of compounds 2 or 3 in
dry THF with 2 or 4 equiv. of phosphonate, respectively, under
nitrogen was treated dropwise with BuLi in hexane at room temp.
The solution immediately darkened and was stirred for about 15
min at room temp. and then concentrated in vacuo. The crude mat-
erial was treated with methanol to allow precipitation of the prod-
uct. After filtration, the red brown powder was dissolved in a min-
imum of THF and was precipitated with methanol.
2bα (R1 p-Me-C6H4, R2 H, R CO2Me): M.p. 129 Ϫ130 °C.
1
Ϫ IR (CHCl3): ν ϭ 1733, 1616 cmϪ1. Ϫ H NMR (CDCl3): δ ϭ
˜
9.35 (s, 1 H), 7.27 (m, 4 H), 6.13 (s, 1 H), 6.08 (s, 1 H),
3.85Ϫ3.84Ϫ3.82 (3 s, 12 H), 2.39 (s, 3 H). Ϫ C28H22O9S6: calcd.
693.9588 for [Mϩ], found 693.9547. Ϫ Elemental analysis: calcd. C
48.39, H 3.19, O 20.72, S 27.68; found C 48.36, H 3.15, O 20.82,
S 27.18.
2dα (R1 H, R2 p-Me-C6H4, R CO2Me): M.p. 231 °C. Ϫ IR
1aββ [R1 Ph, R2 H, R
R
RЈ RЈ
(CH CH)2 ]: M.p.
1
1
(Nujol): ν˜ ϭ 1730, 1710cmϪ1. Ϫ H NMR (CDCl3): δ ϭ 8.06 (d, 160 °C (dec.). Ϫ H NMR (CS2 ϩ C6D6): δ ϭ 7.45Ϫ6.85 (m, 17
3J ϭ 9.0 Hz, 2 H), 7.99 (s, 1 H), 7.60 (m, 3 H), 7.04 (s, 1 H), 6.99 H), 6.19 (s, 1 H), 6.17 (s, 1 H), 6.11 (s, 1 H). Ϫ FABϩ MS: m/z ϭ
3746
Eur. J. Org. Chem. 2001, 3741Ϫ3747

Highly Extended and Sulfur-Rich Vinylogs of Tetrathiafulvalene
FULL PAPER
684 [M]. Ϫ C34H20S8 (685.2): calcd. C 59.61, H 2.94, S 37.44; found
C 59.57, H 2.82, S 36.82.
[1]
[1a] J. R. Ferraro, J. M. Williams Introduction to Synthetic Elec-
trical Conductors, Academic Press, New York, 1987, p. 1Ϫ80.
1aδβ [R1
Ph, R2
H, R
R
(CH2)4 , RЈ RЈ
(CH
[1b]
Ϫ
S. Kagoshima, H. Nagasawa, T. Sambongi, One-Dimen-
1
sional Conductors, Springer Verlag, Berlin, 1987, p. 1Ϫ105. Ϫ
CH)2 ]: M.p. 165 °C. Ϫ H NMR (CS2 ϩ C6D6): δ ϭ 7.16 (m, 5
H), 6.54Ϫ6.83 (m, 4 H), 6.03 (s, 1 H), 5.97 (s, 1 H), 6.87 (s, 1 H),
2.00 (m, 8 H), 1.5 (m, 8 H). Ϫ C34H28S8 (693.2): calcd. C 58.92, H
4.07; found C 59.12, H 4.21.
[1c]
G. Saito, S. Kagoshiwa in The Physics and Chemistry of
Organic Superconductors, Springer Verlag, London, 1990, p.
1Ϫ428.
[2]
[3]
[4]
J. Garin, Adv. Heterocycl. Chem. 1995, 62, 249Ϫ304.
G. Schukat, E. Fanghänel, Sulfur Rep. 1993, 14, 245Ϫ390.
M. R. Bryce, J. Mater. Chem. 1995, 5, 1481Ϫ1496.
1bββ [R1
p-Me-C6H4, R2
H, R
R
RЈ RЈ
(CH
CH)2 ]: M.p.120 °C (dec.). Ϫ 1H NMR (CS2 ϩ C6D6): δ ϭ
7.25Ϫ6.60 (m, 16 H), 6.16 (s, 1 H), 6.12 (s, 1 H), 6.10 (s, 1 H), 2.41
(s, 3 H). Ϫ FABϩ MS: m/z ϭ 698 [M].
[5] [5a]
T. Sugimoto, H. Awaji, I. Sugimoto, Y. Misaki, T. Kawase,
[5b]
S. Yoneda, Z. Yoshida, Chem. Mater. 1989, 1, 535Ϫ547. Ϫ
`
E. Elandaloussi, P. Frere, J. Roncali, P. Richomme, M. Jubault,
[5c]
´
M. Salle, A. Bely-
A. Gorgues, Adv. Mater. 1995, 7, 390. Ϫ
1bβγ [R1
RЈ RЈ
p-Me-C6H4, R2
CH2 CH2 ]: M.p. 140 °C (dec.). Ϫ 1H NMR (CS2
H, R
R
(CH CH)2 ,
asmine, A. Gorgues, J. Michel, N. Soyer, Tetrahedron Lett.
S
[5d]
1991, 32, 2897Ϫ2901. Ϫ
C. Boule, O.Desmars, N. Gautier,
ϩ C6D6): δ ϭ 7.13Ϫ6.92 (m, 12 H), 6.08 (s, 1 H), 6.02 (s, 1 H),
6.00 (s, 1 H), 3.01 (m, 4 H), 2.34 (s, 3 H). Ϫ FABϩ MS: m/z ϭ
750 [M].
P. Hudhomme, M. Cariou, A. Gorgues, Chem. Commun. 1998,
2197Ϫ2198. Ϫ [5e] M. Fourmigue, I. Johannsen, K. Boubekeur,
´
C. Nelson, P. Batail, J. Am. Chem. Soc. 1993, 115, 3752Ϫ3759.
[5f]
Ϫ
T. K. Hansen, M. V Lakshmikantham, M. P. Cava, R.
1bδγ [R1
p-Me-C6H4, R2
H, R
R
(CH2)4 , RЈ RЈ
E. Niziurski-Mann, F. Jensen, J. Becher, J. Am. Chem. Soc.
1
1992, 114, 5035Ϫ5039. Ϫ [5g] A. Benahmed-Gasmi, P. Frere, B.
S
CHS ]: M.p. 192 °C (dec.). Ϫ H NMR (CS2 ϩ C6D6): δ ϭ
`
7.05 (m, 4 H), 5.94 (s, 1 H), 5.93 (s, 1 H), 5.88 (s, 1 H), 3.02 (m, 4
H), 2.33 (s, 3 H), 2.16 (m, 8 H), 1.70 (m, 8 H). Ϫ 13C NMR (CS2 ϩ
C6D6): δ ϭ 138.05, 137.98, 137.64, 134.32, 130.13, 130.04, 126.42,
126.30, 125.47, 124.95, 124.83, 122.75, 113.69, 113.49, 110.39,
104.02, 103.90, 30.30, 30.19, 26.10, 26.00, 25.62, 25.57, 23.36,
23.31, 22.11. Ϫ FABϩ MS: m/z ϭ 746 [M]. Ϫ C33H30S10 (747.4):
calcd. C 53.04, H 4.04, S 42.91; found: C 52.99, H 4.07, S 42.03.
Garrigues, A. Gorgue, M. Jubault, R. Carlier, F. Texier, Tetra-
hedron Lett. 1992, 33, 6457Ϫ6461.
J. Roncali, J. Mater. Chem. 1997, 7, 2307Ϫ2321.
[6]
[7] [7a]
´
M. Salle, M. Jubault, A. Gorgues, K. Boubekeur, M. Four-
´
migue, P. Batail, E. Canadell, Chem. Mater. 1993, 5,
1196Ϫ1198. Ϫ
[7b]
´
M. Salle, M. Jubault, A. Gorgues, K. Bou-
bekeur, P. Batail, R. Carlier, Bull. Soc. Chim. Fr. 1996, 133,
416Ϫ426.
[8]
[9]
Y. Miski, N. Higuchi, H. Fujiwara, T. Yamabe, T. Mori, H.
Mori, S. Tanaka, Angew. Chem. Int. Ed. Engl. 1995, 34,
1222Ϫ1225.
1cβγ [R1
CH2 CH2
Me, Me,
R
R
(CH CH)2 , RЈ RЈ
S
S
]: M.p. 150 °C (dec.). Ϫ 1H NMR (CS2
ϩ
C6D6): δ ϭ 7.07Ϫ6.95 (m, 8 H), 6.08 (s, 1 H), 6.07 (s, 1 H), 3.10
`
Preliminary communication: P. Frere, A. Gorgues, M. Jubault,
(m, 4 H), 1.74 (s, 6 H). Ϫ FABϩ MS: m/z ϭ 676 [M].
F. Texier, J. Cousseau, G. Duguay, Synth. Met. 1993, 55Ϫ57,
1803Ϫ1808.
Electrocrystallizations: These were performed in 10Ϫ1 mol·LϪ1 of
electrolyte support in dichloromethane, previously filtered through
a column of basic alumina. The donor (5·10Ϫ4 mol·LϪ1) was intro-
duced into the anode compartment of a 50-mL H-shaped electro-
crystallisation cell, separated from the cathode compartment by a
porous glass frit. A constant current of 1 µA was applied for 10 d
at room temperature between the two platinum electrodes (wire:
0.5 mm of diameter and 1.5 cm of length). Crystals or powders of
cation-radical salt grew on the anode.
[10] [10a]
K. Ishikawa, K. Akiba, N. Inamoto, Tetrahedron Lett.
1976, 17, 3695Ϫ3698. Ϫ [10b] K. Akiba, K. Ishikawa, N. Inam-
[10c]
oto, Synthesis 1977, 861Ϫ862. Ϫ
K. Akiba, K. Ishikawa,
N. Inamoto, Bull. Chem. Soc. Japan 1978, 51, 2674Ϫ2683. Ϫ
[10d] For a detailed study of the Wittig olefination involving W,
see also: J. M. Fabre, L. Giral, A. Gouasmia, H. J. Cristau, Y.
Ribeill, Bull. Soc. Chim. Belg. 1987, 5, 823Ϫ826.
[11] [11a]
`
P. Frere, A. Belyasmine, Y. Gouriou, A. Gorgues, G. Dug-
uay, K. Boubekeur, P. Batail, Tetrahedron Lett. 1993, 34,
[11b]
`
P. Frere, A. Belyasmine, Y. Gouriou, M.
4519Ϫ4522. Ϫ
Jubault, A. Gorgues, G. Duguay, S. Wood, C. Reynolds, M.
Crystal Data for 1bβγ·PF6: M ϭ 884.08, C33H22F6PS10, dark green
needles (0.26 ϫ 0.20 ϫ 0.1 mm), monoclinic, space group P21/n,
Bryce, Bull. Soc. Chim. Fr. 1995, 132, 975Ϫ984.
[12] [12a]
`
A. S. Benhamed-Gasmi, P. Frere, A. Belyasmine, K. M. A.
˚
˚
˚
a ϭ 11.091(2) A, b ϭ 30.807(5) A, c ϭ 11.169(2) A, β ϭ 91.92(3)°,
Malik, M. B. Hursthouse, A. J. Moore, M. R. Bryce, M. Ju-
3
˚
V ϭ 3814.1(12) A , ρcalcd. ϭ 1.540, Z ϭ 4, 2θmax ϭ 55.94°, Mo-Kα
bault and A. Gorgues, Tetrahedron Lett. 1993, 34, 2131Ϫ2134.
˚
[12b]
radiation (λ ϭ 0.71069 A), T ϭ 293(2) K. X-ray data are collected
´ ´
C. Meziere, M. Salle, M. Fourmigue, Acta Crystallogr.,
Ϫ
with an Enraf-Nonius CAD4 four-circle diffractometer and the
structure was solved by direct methods. Full-matrix least-squares
refinement on F2 with SHELXL-97 converged with R ϭ 0.1028
and wR2 ϭ 0.2115 for 9126 independent reflections with I Ͼ 2σ(I)
and 451 parameters. Crystallographic data (excluding structure fac-
tors) for the structure reported in this paper have been deposited
with the Cambridge Crystallographic Data Centre as supplement-
ary publication no CCDC-155908. Copies of the data can be ob-
tained free of charge on application to CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK [Fax: (internat.) ϩ 44-1223/336-033;
E-mail: deposit@ccdc.cam.ac.uk]
Sect. C 1998, 54, 2005Ϫ2007.
[13]
´
`
T. T. Nguyen, Y. Gouriou, M. Salle, P. Frere, M. Jubault, A.
Gorgues, L. Toupet, A. Riou, Bull. Soc. Chim. Fr. 1996, 133,
301Ϫ308.
[14]
[15]
[16]
Y. Yamashita, Y. Kobayashi, T. Miyashi, Angew. Chem. Int. Ed.
Engl. 1989, 28, 1052Ϫ1053.
`
J. F. Favard, P. Frere, A. Riou, A. Benahmed-Gasmi, A. Gorg-
ues, M. Jubault, J. Roncali, J. Mater. Chem. 1998, 8, 363Ϫ366.
Y. Yamashita, K. Ono, S. Tanaka,K. Imaeda, H. Inokuchi,
Adv. Mater. 1994, 6, 295Ϫ298.
Received November 25, 2000
[O00608]
Eur. J. Org. Chem. 2001, 3741Ϫ3747
3747