Nickel-Catalyzed Cyclopolymerization of Hexyl- and Phenylsilanes
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- 作者：Makoto Tanabe ; Atsushi Takahashi ; Tomoko Fukuta ; Kohtaro Osakada
- 刊名：Organometallics
- 出版年：2013
- 出版时间：February 25, 2013
- 年：2013
- 卷：32
- 期：4
- 页码：1037-1043
- 全文大小：337K
- 年卷期：v.32,no.4(February 25, 2013)
- ISSN：1520-6041
文摘
[Ni(dmpe)2] (dmpe = 1,2-bis(dimethylphosphino)ethane) catalyzed the dehydrogenative polymerization of hexylsilane in toluene at room temperature to produce a mixture of acyclic and cyclic poly(hexylsilanes). A simlar reaction at 70 掳C resulted in selective cyclopolymerization of hexylsilane to yield a cyclic polymer with an average molecular weight of Mn = 1450 (Mw/Mn = 1.01, GPC polystyrene standard). The 1H NMR, 29Si{1H} DEPT NMR, and IR spectroscopic data indicated the presence or absence of the 鈭扴iH2R end groups of the polymer and its acyclic or cyclic structure. Addition of hexylsilane to the solution of the poly(hexylsilanes) containing the acyclic polymer (Mn = 1330) and heating the mixture in the presence of 5 mol % of [Ni(dmpe)2] catalyst formed a polymer composed of the cyclic molecules without a change in the average molecular weight. The polymerization of phenylsilane catalyzed by [Ni(dmpe)2] also yielded the cyclic poly(phenylsilane). The reaction using a mixture of [Ni(cod)2] (cod = 1,5-cyclooctadiene) and PMe3 as the catalyst produced acyclic and/or cyclic poly(phenylsilanes) depending on the conditions. 9,9-Dihydrosilafluorene reacted with [PdMe2(dmpe)] to afford a persilylated palladacyclopentane, [Pd(SiC12H8)4(dmpe)], with four 1,1-silafluorene units.