G. Lai et al. / Journal of Organometallic Chemistry 692 (2007) 3559–3562
3561
ppm and coupling constants J are given in Hz. GC–MS
were measured with TRANCE 2000 DSQ mass spectrom-
eter. The UV and UV–Vis spectra were recorded with a
Shimadzu UV 2200 spectrometer. IR spectra were taken
as thin films with a NICOLET 5700 infrared spectrometer.
GPC was performed with Water 1525. Elemental analysis
was performed on a VARIO EL-III instrument. Melting
points are uncorrected. Column chromatography was per-
formed with silica gel (Wako Pure Chemical Industries,
Ltd., Wakogel C-300). Thin-layer chromatography was
performed on 0.25 mm E. Merck silica gel plates (GF-254).
was refluxed for 24 h, and then cooled to the room temper-
ature. The reaction mixture was quenched with EtOH
(5 mL), poured into the ice-cold hydrochloric acid
(1 mol/L, 30 mL), and then extracted with ether
(3 · 50 mL). The combined organic layer was washed with
saturated NaHCO solution and brine, dried over anhy-
3
drous MgSO , and filtered off. The solvent was removed
4
under reduced pressure, providing a white crude product.
The residual crude polymer was dissolved in THF
(6 mL), and precipitated by the addition of ethanol
(100 mL) to the solution. The molecular weight of the poly-
mer was determined by gel permeation chromatography
(GPC) calibrated by polystyrene standards with chloro-
3
.1. Materials
form as the eluent. Poly(methylvinylsilane) (4a): 588 mg
1
Tetrahydrofuran was distilled from sodium-benzophe-
(84%); H NMR (400 MHz, CDCl ) d 0.06 (s, 3H), 5.35–
3
none immediately prior to use. Sodium metal, magnesium,
zinc, samarium metal and titanium chloride were commer-
cially available products. Ethanol and toluene were purified
by distillation prior to use. The starting material chlorosil-
anes and all solvents of column chromatography were used
without further purification. All reactions were conducted
under a nitrogen atmosphere.
5.40 (m, 3 H); IR (KBr), 2956, 1261, 1105, 1066, 983,
À1
886, 815 cm
;
UV: kmax = 346 nm; M /M = 1.6,
w n
M = 16,860; Anal. Calc. for C H Si: C, 51.42; H, 8.57.
n
3
6
Found: C, 51.20; H, 8.79%.
Acknowledgement
We are grateful to the Natural Science Foundation of
Zhejiang Province (Project No. Y404380) for financial
support.
3
.2. General procedure for the synthesis of disilanes (2a–2g)
As a representative example, the preparation of 1,2-
dimethyl-1,1,2,2-tetraphenyldisilane(MePh SiSiPh Me) is
2
2
References
described. A dry 100 mL flask was charged with Zn powder
2 mmol), TiCl (0.11 mL, 1 mmol) and THF (50 mL). The
(
4
[
1] (a) R. West, in: E. Abel (Ed.), Comprehensive Organometallic
Chemistry, Pergamon Press, Oxford, England, 1983, p. 365;
(b) J.M. Zeigler, Synth. Met. 28 (1989) 581;
mixture was refluxed for 2 h under nitrogen. When black
slurry was formed, a solution of chlorodiphenylmethylsi-
lane (2 mmol) in THF (5 mL) was added to the reaction
mixture immediately. The black reaction mixture was stir-
red for another 20 h in refluxing THF. After cooled to
room temperature, the mixture was quenched with dilute
ice-cold hydrochloric acid (1 mol/L, 30 mL), and extracted
with ether (3 · 40 mL). The combined organic layer was
(
c) K. Matyjaszewski, M. Cypryk, H. Frey, J. Hrkach, H.K. Kim,
M. Moeller, K. Ruehl, M. White, J. Macromol. Sci., Chem. A 28
(
(
(
1991) 1151;
d) K. Matyjaszewski, J. Inorg. Organomet. Polym. 1 (1991) 463;
e) S. Yajima, J. Hayashi, M. Omori, Chem. Lett. (1975) 931;
(f) Y. Hasegawa, K. Okamura, J. Mater. Sci. 20 (1985) 321;
(
(
g) R. Srinivasan, Science 234 (1986) 559;
h) R.D. Miller, C.G. Willson, G.M. Wallraff, N. Clecak, R.
washed with saturated NaHCO solution and brine, dried
3
Sooriyakumaran, J. Michl, T. Karats, A.J. Mckinley, K.A. Klingen-
smith, J. Downing, Polym. Eng. Sci. 29 (1989) 882;
over anhydrous MgSO , and filtered off. The solvent was
4
concentrated under reduced pressure. The residue recrys-
tallized from ethanol to give the product MePh SiSiPh Me
(
i) R.D. Miller, G.M. Wallraff, N. Clecak, R. Sooriyakumaran, J.
2
2
Michl, T. Karats, A.J. Mckinley, K.A. Klingensmith, J. Downing,
Polym. Mater. Sci. Eng. 60 (1989) 49;
(
2a). This disilane was identified by comparison with an
(
j) R.D. Miller, Angew. Chem., Int. Ed. Engl. Adv. Mater. 28 (1989)
733.
2] (a) For review see: R. West, J. Organomet. Chem. 300 (1986) 327;
b) R.D. Miller, J. Michl, Chem. Rev. 89 (1989) 1359;
authentic compound (IR, GC–MS and NMR), which was
described in the literature [12].
1
[
(
3.3. General procedure for the synthesis of
poly(methylvinylsilane)
(c) H. Sakurai (Ed.), Advanced Technology of Organosilicon Poly-
mer, CMC Co. Ltd, Tokyo, 1996;
(
(
d) R.G. Jones, S.J. Holder, in: R.G. Jones, W. Ando, J. Chojnowski
Eds.), Silicon-Containing Polymers, the Science and Technology of
In a 100 mL three-necked flask equipped with a reflux
condenser and a dropping funnel was placed samarium
powder (4 mmol), zinc powder (20 mmol), TiCl (1.1 mL,
Their Synthesis and Applications (Section 3), Kluwer Academic
Publishiers, Dordrecht, 2000, pp. 353–573, and references cited
therein.
4
[
[
3] (a) Sonochemical coupling of chlorosilanes: H.K. Kim, K. Mat-
yjaszewski, J. Am. Chem. Soc. 110 (1988) 3321;
1
0 mmol), and freshly distilled (sodium/benzophenone
ketyl) THF (60 mL) under nitrogen atmosphere. The mix-
ture was refluxed for 2 h under nitrogen. When black slurry
was formed, dichloromethylvinylsilane (10 mmol) was
dropped to the reaction mixture. Then the flask was set
in an oil bath maintained at 70 ꢁC. The reaction mixture
(
b) K. Matyjaszewski, D. Greszta, J.S. Hrkach, H.K. Kim, Macro-
molecules 28 (1995) 59.
4] (a) Ring opening polymerization and the polymerization of masked
disilenes: K. Matyjaszewski, Y. Fupta, M. Cypryk, J. Am. Chem.
Soc. 113 (1991) 1046;