Intermediates in Charge-Transfer Polymerizations

研究者对电荷转移聚合的新解释包括四亚甲基两性离子和双自由基作为关键中间体。为了支持这一概念，他将以新颖的方式生成各自的四亚甲基，并将研究它们作为引发剂的行为。潜在的来源包括环丁烷、环砜和环偶氮前体的热裂解。含离去基的环丁烷可用于生成阳离子引发物。路易斯酸将被用来催化形成四亚甲基，包括双自由基和锌离子，这取决于路易斯酸。这将是一个强大的控制起始的新工具。在亲电性或亲核性烯烃引发剂中适当的基因离子离去基将控制增殖反应和引发反应。这一概念将用于阳离子和阴离子的配位聚合。这一概念将扩大到对其他聚乙烯的研究，特别是对三亚甲基、五亚甲基和六亚甲基的研究。这项研究是聚合物项目努力的一部分，旨在了解聚合物合成的基本原理，以便能够控制聚合物的结构。

The investigator's new interpretation for charge-transfer polymerization involves tetramethylene zwitterions and diradicals as the key intermediates. To support this concept, he will generate the respective tetramethylenes in novel ways, and will examine their behavior as initiators. Potential sources include thermolysis of cyclobutanes, cyclic sulfones, and cyclic azo precursors. Cyclobutanes containing leaving groups will be used to generate cationic initiating species. Lewis acids will be used to catalyze the formation of tetramethylenes both diradical and zitterionic, depending on the Lewis acid. This will be a powerful new tool for control of initiation. Appropriate gegenionic leaving groups in electrophilic or nucleophilic olefin initiators will control the propagation reaction as well as the initiation. This concept will be used in both coordinated cationic and anionic polymerizations. The concept will be broadened to the study of other polymethylenes, in particular trimethylenes, pentamethylenes, and hexamethylenes. This research is part of the Polymers Program's effort to understand the fundamentals of polymer synthesis so as to be able to control the structure of polymers.