【摘要】 利用分子模拟技术构建了丙烯单体以不同方式与茂金属催化剂活性中心配位、插入形成的π配合物和四元环过渡态的模型;计算了四元环过渡态和π配合物构象能的差。发现催化剂中取代基的大小及其所处位置会明显影响构象能的差,从而显著地影响茂金属催化剂的立体选择性。关于取代基影响茂金属催化剂立体选择性结果的阐述,将有助于人们理性地设计和开发立体选择性更加理想的茂金属催化剂。更多还原

【Abstract】 Molecular simulation techniques were used to build various models of π complexes and four-member ring transition state, and their conformational energy difference was calculated. The relationship between conformational energy difference and stereoselectivity of metallocene catalysts was also investigated. The position of the substituents in metallocene catalysts has a significant effect on conformational energy difference, while the size of substituents, depending on their position, has rather different effect on stereoselectivity of metallocene catalysts. A clear elucidation relating the size and position of substituents and stereoselectivity of metallocene catalysts may lead to a more rational way for designing and developing metallocenes with ideal stereoselectivity.更多还原