Homogeneous Models of Ziegler-Natta Catalysts

齐格勒-纳塔催化剂的均相模型

• 批准号: 8917586
• 负责人: Gregory Girolami
• 金额: $ 21.3万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-11-15 至 1993-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8917586&HistoricalAwards=false
• 关键词: Homogeneous; Models; Ziegler; Natta; Catalysts

With support from the Inorganic, Bioinorganic and Organometallic Chemistry Program, Dr. Gregory S. Girolami will synthesize and study soluble models of the heterogeneous catalysts used widely for the industrial synthesis of such polymers as polyethylene, the so-called Ziegler-Natta catalysts. The results of the project are expected to aid in the identification of the species responsible for the catalytic activity and in the formulation of a detailed mechanism for the catalytic process. Homogeneous models of Ziegler-Natta catalysts will be synthesized and studied, with particular emphasis on the preparation and reactivity of electronically unsaturated alkyl derivatives of the early transition elements. Among the effects to be examined are the unexpected spin-state changes which occur as a result of the extremely strong pi-electron donation by the early transition metals, e.g., those of group 4, to ligand acceptor orbitals. Although octahedral geometries are generally assumed for Ziegler-Natta catalysts, d-zero metal alkyls can adopt non-octahedral geometries, and the role of the latter geometries in the catalytic process will be probed. Studies of new chromium-based polymerization systems and mechanistic studies related to the thermolysis of transition metal alkyls will be pursued also.

在无机，生物有机和有机金属化学计划的支持下，Gregory S. Girolami博士将合成和研究用于多种聚合物（如聚乙烯），所谓的Ziegler-Natta催化剂等聚合物的工业合成的异质催化剂的可溶模型。该项目的结果有望有助于鉴定负责催化活性的物种，并为催化过程的详细机制制定。 Ziegler-Natta催化剂的均匀模型将合成和研究，特别强调了早期过渡元素电子不饱和烷基衍生物的制备和反应性。在要研究的效果中，是由于早期过渡金属（例如4组的pi-electron捐赠）捐赠了非常强大的Pi电子捐赠而导致的意外自旋状态变化，例如4组对配体受体轨道。尽管通常假定为Ziegler-Natta催化剂八面体几何形状，但D-Zero金属烷基可以采用非二十字体的几何形状，并且将探测后一种几何形状在催化过程中的作用。 还将研究与过渡金属烷基热解的新的基于铬的聚合系统和机械研究。