Polymethylene Intermediates in Thermal and Photoinduced "Charge-Transfer" Polymerization

成键引发理论认为，在富电子烯烃与贫电子烯烃的环加成反应中遇到的四亚甲基中间体也是这些体系中观察到的自发聚合的真正引发剂。两性离子中间体引发给体烯烃和/或受体烯烃的离子均聚合，而双自由基中间体引发自由基共聚合。在这个项目的前几个阶段，这一假设已经被证明适用于两性离子体系和双自由基体系。这一理论现在正在扩展到富电子的双烯与贫电子的烯烃的反应。有人认为，在许多此类体系中发生的自发聚合是由六亚甲基中间体引发的，该中间体可以是两性离子的，也可以是双自由基的。类似于热反应，该理论也将扩展到富电子和贫电子的烯烃体系中的光诱导聚合。在这里，再次提出四亚甲基中间体，两性离子或双自由基，是观察到的聚合的引发剂。

The bond - forming initiation theory proposes that the tetramethylene intermediates, encountered in the cycloaddition reaction of electron-rich with electron-poor olefins, are also the true initiators for the spontaneous polymerizations observed in these systems. Zwitterionic intermediates initiate ionic homopolymerization of either donor and/or acceptor olefin, while diradical intermediates initiate the radical copolymerization. In previous phases of this project, this hypothesis has been proven for a zwitterionic and for a diradical systems. This theory is now being extended to reactions of electron- rich dienes with electron-poor olefins. It is proposed that the spontaneous polymerizations which occur in many of these systems are initiated by a hexamethylene intermediate, which can be either zwitterionic or diradical. In analogy with the thermal reactions, the theory will also be extended to photoinduced polymerization in electron-rich and electron-poor olefin systems. Here again, it is proposed that a tetramethylene intermediate, zwitterionic or diradical, is the initiator of the observed polymerizations.