The Study on the Mechanism of Conjugative Stabilization of Phenyl Cations

1)对取代苯阳离子的优化结构进行了半经验和从头算计算，结果表明，取代苯阳离子的优化结构具有“非平面”结构，其稳定性与非平面性密切相关。2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2)2丙基苯氯的光解使产物通过2-丙基苯基阳离子得到，类似于2-丙基苯重氮离子的热分解。3)溶剂的影响在三氟代芳烃和氯化物的光解反应中，研究了间位取代基的供电子能力和两种产物通过芳基自由基和芳基阳离子中间体离开的电子亲和力，其中溶剂中芳基自由基的夺氢和溶剂对芳基阳离子的亲核键合是竞争发生的。4)在邻羟基苯氯的光解反应中，中间氧化苯基阳离子的收缩与亲核溶剂对羟基苯阳离子的攻击竞争发生。通过计算对实验结果进行了分析。

This is a fundamental research to investigate the structure-reactivity relationship of phenyl cations, which are highly reactive and important intermediates for synthesis, with respect to the mechanism of the conjugative stabilization of phenyl cations.1)Semi-empirical and ab initio calculations on the optimized structures of substituted phenyl cations revealed that highly stabilized phenyl cations with electron-donating groups at meta position have "non-planar" structures, whose stability and nonplanality are closely related.2)Photosolvolysis of 2-propylphenyl chloride gave rise to the products via 2-propylphenyl cation intermediate which were similarly obtained in the thermal decomposition of 2-propylbenzenediazonium ions.3)The effects of solvents, electron-donating ability of meta-substituents, and electron-affinity of leaving grous on the ratio of two products via aryl radical and aryl cation intermediates were investigated in the photo-solvolysis of aryl triflates and chlorides, where hydrogen abstraction of aryl radicals from solvent and nucleophilic attach of solvent on aryl cations occured competitively.4)In the photo-solvolysis of ortho-hydroxyphenyl chloride ring contraction of the intermediate oxido-phenyl cations occured competitively with the nucleophilic solvent attack on the hydroxyphenyl cations. The experimental results were investigated by computational calculations.