Intermediates in Charge-Transfer Polymerizations

研究者对电荷转移的新解释 聚合涉及四亚甲基两性离子和双自由基 作为关键的中间体。 为了支持这一概念，他将 以新的方式产生相应的四亚甲基， 检查他们作为发起人的行为。 潜在来源包括 环丁烷、环砜和环偶氮的合成 前体 将使用含有离去基团的环丁烷 以产生阳离子引发物质。 刘易斯酸将是 用于催化四亚甲基的形成， 和zitterionic，取决于刘易斯酸。 这将是一 控制起爆的强大新工具。 适当 亲电或亲核烯烃中的负离子离去基团 引发剂将控制增长反应以及 入会仪式 这一概念将用于协调 阳离子和阴离子聚合。 这个概念将是 扩大到其他聚亚甲基的研究，特别是 三亚甲基、五亚甲基和六亚甲基。 这项研究是聚合物计划的一部分， 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.