Reactive Cationic Zr(IV) and Ti(IV) Complexes Containing Labile Ligands

含有不稳定配体的反应性阳离子 Zr(IV) 和 Ti(IV) 配合物

• 批准号: 8816445
• 负责人: Richard Jordan
• 金额: $ 10万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-15 至 1990-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8816445&HistoricalAwards=false
• 关键词: Reactive; Cationic; Zr; IV; Ti

Ziegler-Natta catalysts are used widely as industrial catalysts for the synthesis of polymers. The zirconium and titanium compounds which will be studied in this project are related to soluble Ziegler-Natta catalysts. This project is expected to provide a better understanding of how these catalysts function and to provide information needed to design more specific and more efficient catalysts for polymer synthesis. General methods for the synthesis and isolation of cationic organozirconium complexes of the type bis-Cp-Zr(R)(L) where L is a labile ligand have been discovered. The organozirconium complexes are highly reactive. Their Zr-R bonds undergo rapid insertion of ketones, nitriles and other polar unsaturated substrates, and the THF complexes polymerize ethylene in the absence of an A1 cocatalyst. These observations support recent proposals that cationic Ti and Zr complexes are active species in soluble Ziegler-Natta catalyst systems. The cationic organozirconium complexes are also easily hydrogenated to synthetically useful cationic hydrides. The research plan is to synthesize an extensive series of Cp2M(R)(L) complexes (M = Ti, Zr) and to study the scope and mechanisms of their reactions with olefins and other unsaturated substrates, and with hydrogen. These novel compounds provide an opportunity to study the fundamental features of insertion reactions of M-R bonds (M = Ti, Zr) in the absence of the many complications caused by A1 cocatalysts. Also included in this project is research to develop asymmetric organic syntheses based on chiral cationic Cp2M(R)(L) complexes.

Ziegler-Natta催化剂被广泛用作合成聚合物的工业催化剂。 该项目中将研究的锆和钛化合物与可溶性Ziegler-Natta催化剂有关。 预计该项目将更好地了解这些催化剂如何功能，并提供为聚合物合成设计更具体，更有效的催化剂所需的信息。 已经发现了L是不稳定的配体的BIS-CP-ZR（R）（R）型阳离子有孔氮化物复合物的合成和分离的一般方法。 有条件的复合物具有高度反应性。 它们的ZR-R键在没有A1 cocatalyst的情况下快速插入酮，硝酸盐和其他极性不饱和底物，而THF络合物将聚合乙烯化。 这些观察结果支持了最近的建议，即阳离子Ti和Zr复合物是可溶性Ziegler-Natta催化剂系统中的活性物种。 阳离子有条件的配合物也很容易被氢化为合成有用的阳离子氢化物。 该研究计划是合成一系列CP2M（R）（L）（M = Ti，Zr）的广泛系列，并研究其与烯烃和其他不饱和底物以及与氢的反应的范围和机制。 这些新颖的化合物提供了一个机会，可以在没有A1 cocatalysts引起的许多并发症的情况下研究M-R键（M = Ti，Zr）的插入反应的基本特征。 该项目还包括研究基于手性阳离子CP2M（R）（L）复合物的不对称有机合成。