Transition Metal Catalyzed Olefin Polymerizations: Mechanistic Studies and Catalyst Design

Maurice Brookhart博士，北方大学化学系 卡罗莱纳-查佩尔山，由无机，生物无机，和 化学系的有机物方案， 联合国多学科活动办公室提供的仪器 数学和物理科学理事会，为机械和 后过渡金属烯烃聚合催化剂的设计研究。 该项目的重点将是Ni（II）和Pd（II）的研究 大体积α-二亚胺的络合物，其具有例如 以通过配体变化来控制聚合物链支化。严格 聚合反应的机理研究将进行 为了了解控制行为的因素 催化剂的性质，并决定了产物的性质， 聚合物的多种基于α-二亚胺的催化剂，具有多种 配体结构，将合成的目的是探测 配体结构对聚合物微观结构的影响及机理 单体链化。将对这些催化剂进行评价， 新单体的聚合和共聚。利用来自 这些研究新的中性Ni（II）和Pd（II）催化剂体系将是 制备含有大体积二齿阴离子配体。这些系统应 表现出很大的官能团耐受性，并且是特别好的催化剂 用于乙烯和极性烯烃的共聚。 深入的研究一直致力于了解基本的 金属催化的烯烃聚合的方面和这些方面的结果 已经使用研究来开发新的催化剂。这些已经 巨大的重要贡献，因为超过300亿英镑的 美国每年生产聚烯烃。大部分 商业烯烃聚合催化剂基于早期转变 或镧系金属。在这个项目中，一系列高度通用的后期 将研究过渡金属催化剂。这些将提供 关于催化剂如何使烯烃彼此连接的基本信息 在聚合过程中，以及新的催化剂体系， 潜在的工业应用。

Dr. Maurice Brookhart, Department of Chemistry, University of North Carolina - Chapel Hill, is supported by the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division, with a contribution for instrumentation from the Office of Multidisciplinary Activities of the Mathematical and Physical Sciences Directorate, for mechanistic and design studies of late transition metal olefin polymerization catalysts. The major thrust of the project will be the study of Ni(II) and Pd(II) complexes of bulky alpha-diimines, which have, for example, the ability to control polymer chain branching through ligand variation. Rigorous mechanistic studies of the polymerization reactions will be carried out in order to gain understanding of the factors that control the behavior of the catalysts and that determine the properties of the resultant polymer. A variety of alpha-diimine based catalysts, with a variety of ligand architectures, will be synthesized with the objective of probing the effect of ligand structure on polymer microstructure and mechanisms of monomer enchainment. These catalysts will be evaluated for the polymerization and copolymerization of new monomers. Using insights from these studies new neutral Ni(II) and Pd(II) catalyst systems will be prepared containing bulky bidentate anionic ligands. These systems should exhibit great functional group tolerance and be especially good catalysts for the copolymerization of ethylene and polar olefins. Intensive research has been directed toward understanding fundamental aspects of metal-catalyzed olefin polymerization and the results of these studies have been used to develop new catalysts. These have been enormously important contributions since over thirty billion pounds of polyolefin are produced in the United States each year. Most of the commercial olefin polymerization catalysts are based on early transition or lanthanide metals. In this project a series of highly versatile late transition metal catalysts will be investigated. These will provide fundamental information on how catalysts join olefins to one another during the polymerization process as well as new catalyst systems with potential industrial applications.