Investigation of PPV Analogue Oligomers
(s, 6 H), 2.28 (s, 3 H), 6.81 (s, 4 H), 6.97 (d, J ϭ 16 Hz, 1 H), 6.81 a pale yellow solid precipitated. The precipitate was collected by
FULL PAPER
(d, J ϭ 16 Hz, 1 H), 7.04 (m, 5 H), 7.08 (d, J ϭ 8 Hz, 2 H), 7.18
filtration, rinsed with ethanol and dried. Proton NMR spectro-
scopic analysis of the crude solid indicated a mixture of E and Z
(s, 2 H), 7.31 (d, J ϭ 8 Hz, 2 H), 8.59 (d, 1 H, JH,P ϭ 25 Hz). 31P
NMR (CDCl3, ppm): δ ϭ 239.2 ppm. HRMS (FAB, MHϩ, m/z): isomers. Complete isomerization to the E form was successfully
calcd. for C40H40P, 551.2868; found, 551.2864.
carried out by heating a toluene solution of the crude solid to reflux
for 3 hours in the presence of a crystal of iodine, followed by rins-
ing with 5 % Na2SO3 and removal of volatiles in vacuo. Compound
xi was isolated as a yellow powder (12.5 g, 51.9 %). 1H NMR
(CDCl3, ppm): δ ϭ 1.34 (s, 9 H), 6.95, d, 1 H, J ϭ 16 Hz), 7.05 (d,
J ϭ 16 Hz, 1 H),7.09 (d, J ϭ 16 Hz, 1 H), 7.14 (d, J ϭ 16 Hz, 1
H), 7.22 (s, 1 H), 7.36Ϫ7.40 (m, 4 H), 7.45Ϫ7.52 (m, 6 H); m.p.
139Ϫ141 °C.
1,4-[DmpЈP؍
C(H)]2C6H4 (5): Trimethylphosphane (0.17 g,
2.3 mmol) was added to a mixture of zinc dust (0.074 g, 1.1 mmol),
DmpЈPCl2 (0.30 g, 0.56 mmol), and terephthalaldehyde (0.038 g,
0.28 mmol). A yellow-orange colour developed almost immediately
and after stirring for 10 hours the mixture was filtered and the
solvent removed in vacuo. The crude solid was dissolved in boiling
hexanes, filtered, and the solvent removed in vacuo. The resultant
solid was then rinsed with a small amount of warm acetonitrile
and the final product was precipitated from diethyl ether/hexanes
solution at Ϫ35 °C as a yellow-orange solid (0.11 g, 39 %). 1H
NMR (CDCl3, ppm): δ ϭ 1.98 (s, 24 H), 2.18 (s, 12 H), 2.26 (s, 6
H), 6.77 (s, 8 H), 6.94 (d, J ϭ 16 Hz, 2 H), 7.02Ϫ7.08 (m, 10 H),
7.15 (s, 4 H), 7.29 (d, J ϭ 8 Hz, 4 H), 8.40 (d, 2 H, JH,P ϭ 19 Hz).
31P NMR (CDCl3, ppm): δ ϭ 242.3. MS (FAB, MHϩ, m/z): calcd.
for C74H73P2, 1024; found, 1024.
(E,E)-4-Iodo-3,5-dimesityl-4Ј-(4-tert-butylstyryl)stilbene (DmpЈЈI):
A solution of (E,E)-3,5-dichloro-4Ј-(4-tert-butylstyryl)stilbene (xi)
(10.0 g, 24.5 mmol) in THF (125 mL) was cooled to Ϫ78 °C and
n-butyllithium (10.3 mL, 2.5 in hexanes, 25.8 mmol) was added
dropwise via cannula. After 1 hour of stirring at Ϫ78 °C, a solution
of mesitylmagnesium bromide [prepared by reaction of 2-bromo-
mesitylene (17.1 g, 85.9 mmol) and Mg turnings (2.98 g, 123 mmol)
in THF (85 mL)] was added dropwise via cannula at Ϫ78 °C. After
warming to room temperature over a 3 hour period, the solution
was then heated to reflux for an additional 10 hours. After cooling
to room temperature the flask was placed in an ice bath and iodine
(15.6 g, 61.4 mmol) was added in 3 g portions. After the exothermic
reaction was complete and the characteristic iodine colour persisted
in solution for 15 minutes, 5 % Na2SO3 (200 mL) was added to
quench excess iodine and the solution became yellow. The organic
layer was extracted with diethyl ether (200 mL), rinsed with water
(2 ϫ 200 mL aliquots) and volatiles removed to yield a viscous oil.
Three precipitations of the material from a boiling ethanol solution
subsequently cooled to Ϫ7 °C gave the product as a pale yellow
DmpЈPH2: To a stirred suspension of LiAlH4 (0.18 g, 4.7 mmol) in
THF (25 mL) was added solid DmpЈPCl2 (1.2 g, 2.3 mmol) in small
portions over 5 minutes. After stirring for 6 hours the mixture was
filtered and volatiles removed in vacuo to give an off-white solid.
This material was then dissolved in diethyl ether and filtered
through alumina twice. Removal of volatiles in vacuo gave the
product as an off-white powder (0.89 g, 85 %). 1H NMR (C6D6,
ppm): δ ϭ 2.12 (s, 3 H), 2.14 (s, 12 H), 2.23 (s, 6 H), 3.31 (d, 2 H,
JPH ϭ 212 Hz), 6.92 (s, 4 H), 6.98 (d, J ϭ 7 Hz, 2 H), 7.02 (d, J ϭ
4
16 Hz, 1 H), 7.16 (d, J ϭ 16 Hz, 1 H), 7.18 (d, 2 H, JH,P ϭ 2 Hz),
7.28 (d, J ϭ 7 Hz, 2 H). 31P NMR (C6D6, ppm): δ ϭ Ϫ146.3 (t,
J ϭ 212 Hz).
1
powder (2.05 g, 11.8 %). H NMR (CDCl3, ppm): δ 1.35 (s, 9 H),
2.05 (s, 12 H), 2.39 (s, 6 H), 6.90 (s, 4 H), 7.03Ϫ7.14 (m, 4 H),
7.39Ϫ7.42 (m, 4 H), 7.46Ϫ7.52 (m, 6 H).
1,4-[DmpЈP؍
P]2C6Ar4 (Ar ؍
4-tert-butylphenyl) (9): A solution of
[Li(Et2O)][P(H)DmpЈ][45] (0.19 g, 0.35 mmol) in diethyl ether
(20 mL) was added at room temperature to a rapidly stirred suspen-
Acknowledgments
The authors thank Prof. Christoph Weder and Prof. Malcolm E.
Kenney for use of instrumentation and the National Science Foun-
dation (CHE-0202040) for support.
[22]
sion of Cl2P-(p-C6Ar4)-PCl2 (0.14 g, 0.17 mmol) in diethyl ether
(20 mL) over a 10 min period. During this time a fine white precipi-
tate formed. The solvent was reduced in volume to 20 mL and a
solution of DBU (0.053 g, 0.35 mmol) in diethyl ether (5 mL) was
added. Upon addition, the solution became orange and eventually
nearly red over a 1 h period after which time the reaction mixture
was filtered and the solvent removed in vacuo. The solid material
was precipitated from n-pentane at Ϫ35 °C to give 0.18 g of red
[1] [1a]
H. Shirakawa, E. J. Louis, A. G. MacDiarmid, C. K. Chi-
ang, A. J. Heeger, J. Chem. Soc., Chem. Commun. 1977, 578.
[1b]
C. K. Chiang, C. R. Fincher, Y. W. Park, A. J. Heeger, H.
Shirakawa, E. J. Louis, Phys. Rev. Lett. 1977, 39, 1098.
J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Marks,
1
powder (51 %). H NMR (C6D6, ppm): δ ϭ 1.13 (s, 36 H), 1.93 (s,
[2]
24 H), 2.09 (s, 6 H), 2.33 (s, 12 H), 6.65 (d, J ϭ 8 Hz, 8 H), 6.86
(d, J ϭ 8 Hz, 8 H), 6.91Ϫ6.95 (m, 16 H), 7.11 (s, 4 H), 7.20 (d,
J ϭ 8 Hz, 4 H). 31P NMR (CDCl3, ppm): δ ϭ 479.7 (d, J ϭ
570 Hz), 524.8 (d, J ϭ 570 Hz).
K. MacKay, R. H. Friend, P. L. Burn, A. B. Holmes, Nature
1990, 347, 539Ϫ541.
[3]
[3a] H. Shirakawa, Angew. Chem. Int. Ed. 2001, 40, 2574Ϫ2580.
[3b]
A. G. MacDiarmid, Angew. Chem. Int. Ed. 2001, 40,
[3c]
2581Ϫ2590.
2591Ϫ2611.
A. J. Heeger, Angew. Chem. Int. Ed. 2001, 40,
(E,E)-3,5-Dichloro-4Ј-(4-tert-butylstyryl)stilbene (xi): A solution of
(E)-4-bromomethyl-4Ј-tert-butylstilbene (29.6 g, 89.9 mmol)[32] and
triphenylphosphane (25.8 g, 98.2 mmol) was heated to reflux in
toluene (200 mL) for four hours. The resultant suspension was
cooled to room temperature and the fine white precipitate collected
by filtration. The solid was rinsed with n-pentane and dried, giving
49.9 g (67.4 %) (E)-4-(4-tert-butylstyryl)benzyltriphenylphosphon-
ium bromide. A suspension of this material (35.0 g, 59.2 mmol) and
3,5-dichlorobenzaldehyde (11.4 g, 65.1 mmol) in THF (200 mL)
was added over 30 minutes to a THF (50 mL) solution of tBuOK
(7.36 g, 65.1 mmol) containing 18-crown-6 (0.160 g, 0.605 mmol).
The mixture was then stirred for 12 hours, and quenched by pour-
ing into an equal volume of 10 % methanolic HCl, upon which
[3d]
Handbook of Conductive Materials and Poly-
mers (Ed.: H. S. Nalwa); John Wiley & Sons: New York, 1997.
[3f]
Handbook of Conducting Polymers, 2 ed. (Eds.: T. A. Sko-
theim, R. L. Elsenbaumer, J. R. Reynolds); Dekker: New
York, 1998.
[4]
[5]
A. Kraft, A. C. Grimsdale, A. B. Holmes, Angew. Chem. Int.
Ed. 1998, 37, 402Ϫ428, and references cited therein.
Phosphorus: The Carbon Copy (Eds.: K. B. Dillon, F. Mathey,
J. F. Nixon); John Wiley & Sons: New York, 1998.
[6] [6a]
Multiple Bonds and Low Coordination in Phosphorus Chem-
istry (Eds.: M. Regitz, O. J. Scherer); Thieme Verlag: Stuttgart,
[6b]
1990.
L. Nyulaszi, T. Veszpremi, J. Reffy, J. Phys. Chem.
[6c]
1993, 97, 4011Ϫ4015.
3463Ϫ3503.
P. P. Powe r, Chem. Rev. 1999, 99,
Eur. J. Inorg. Chem. 2004, 998Ϫ1006
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1005