论文部分内容阅读
本文将聚4-乙烯吡啶(PVPy)、聚1-甲基-4-乙烯吡啶季铵碘(PVPyMe~+I~-)和4-乙烯吡啶/1-甲基-4-乙烯吡啶季铵碘共聚物[P(VPy-VPyMe~+I~-)]分别与四羰基二氯二铑反应制备成高分子铑(Ⅰ)催化剂,并考察了它们各自在甲醇羰化反应中的催化行为.结合IR光谱对这些催化剂结构的分析研究表明,以上4-乙烯吡啶类高分子链上所含的功能基各自与铑(Ⅰ)配合物离子之间以不同的键联方式所产生的不同结构的活性物种对催化反应性能有着显著的影响,具有双配位的螫合型稳定结构的 Rh(Ⅰ)/PVPy催化剂,表现出较差的催化反应活性,而离子键合型的Rh(Ⅰ)/PVPyMe~1I~-和杂键合型的Rh(Ⅰ)/P(VPy-VPyMe~1I~-)催化剂均表现较佳的反应性能,特别是Rh(Ⅰ)/P(VPy—VPyMe~1I~-),由于其形成具有更强亲核性的五配位中间过渡态参与反应过程,从而在较大程度上提高了催化反应速率.
Polyvinylpyridine (PVPy), poly (1-methyl-4-vinylpyridine) quaternary ammonium iodide (PVPyMe ~ + I ~ Copolymers [P (VPy-VPyMe ~ + I ~ -)] were respectively reacted with tetracarbonyl dichloride rhodium dichloride to prepare high molecular rhodium (Ⅰ) catalysts, and their catalytic activities in the methanol carbonylation reaction were investigated. IR spectra of the catalyst structure analysis showed that the 4-vinyl pyridine-based polymer chain containing functional groups and rhodium (Ⅰ) complex ions generated by different bonding between the different structures of the activity Species have a significant influence on the catalytic performance. Rh (Ⅰ) / PVPy catalyst with bidentate coordination type stable structure shows poor catalytic activity. However, the ionic bonding type Rh (Ⅰ) / PVPyMe The results showed that Rh (Ⅰ) / P (VPy-VPyMe ~ 1I ~ -) hybrid catalyst exhibited good reaction performance especially Rh (Ⅰ) / P ), Due to its formation of a more nucleophilic pentacoordinated intermediate transitional state involved in the reaction process, which to a large extent improve the catalytic reaction rate.