Highly active cationic rhodium(I) precatalysts for the ambient temperature ring-opening polymerization of [1]silaferrocenophanes and tetramethyldisilacyclobutane
Highly active cationic rhodium(I) precatalysts for the ambient temperature ring-opening polymerization of [1]silaferrocenophanes and tetramethyldisilacyclobutane
复制标题
用于[1]硅二茂铁和四甲基二硅杂环丁烷常温开环聚合的高活性阳离子铑(I)预催化剂
DOI：
10.1021/om020492j
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
I. Manners
中科院分区：
文献类型：
--
作者：
K. Temple;A. Dziadek;I. Manners
阳离子铑（I）配合物[Rh（1，5-cod）2]A（A = OTf，PF 6，1，5-cod = 1，5-环辛烯）已被证明对硅桥连[1]二茂铁烷（例如，fcSiMe 2（1a），fc = Fe（η5-C5 H4）2），以定量地提供高分子量（Mn > 105）聚二茂铁基硅烷（例如，[fcSiMe2]n（2a））。然而，所得聚二茂铁溶液长时间暴露于催化剂导致分子量急剧下降。过渡金属催化的四甲基二硅杂环丁烷（6）的ROP和该物种与1a的共聚也被证明是容易可行的，其中[Rh（1，5-cod）2]OTf形成高分子量聚碳硅烷均聚物（7）。（Mn = 4.20 × 105至1.08 × 106，PDI = 1.39−2.08）和聚（碳硅烷-r-二茂铁基硅烷）（8）共聚物（Mn = 4.63 × 105，PDI = 1.86）。[Rh（1，5-cod）（dmpe）] PF 6（dmpe =双（二甲基膦基乙烷））作为ROP催化剂的活性较低，但该催化剂的活性较低。
The cationic rhodium(I) complexes [Rh(1,5-cod)2]A (A = OTf, PF6, 1,5-cod = 1,5-cyclooctadiene) have been shown to exhibit high catalytic activity for the transition metal-mediated ring-opening polymerization (ROP) of silicon-bridged [1]ferrocenophanes (e.g., fcSiMe2 (1a), fc = Fe(η5-C5H4)2), to quantitatively afford high molecular weight (Mn > 105) polyferrocenylsilanes (e.g., [fcSiMe2]n (2a)). However, prolonged exposure of the resulting polyferrocene solution to the catalyst resulted in a dramatic molecular weight decline. Transition metal-catalyzed ROP of tetramethyldisilacyclobutane (6) and copolymerization of this species with 1a also proved readily feasible with [Rh(1,5-cod)2]OTf forming high molecular weight polycarbosilane homopolymer (7) (Mn = 4.20 × 105 to 1.08 × 106, PDI = 1.39−2.08) and poly(carbosilane-r-ferrocenylsilane) (8) copolymer (Mn = 4.63 × 105, PDI = 1.86), respectively. While [Rh(1,5-cod)(dmpe)]PF6 (dmpe = bis(dimethylphosphinoethane)) proved less active as a ROP catalyst, this spec...