用量子化学的Hartree—Fock理论在3—21G＊水平上对单重态卡宾及其取代物与苯的环加成反应机理进行了研究．用IRC对过渡态进行了确认．结果表明，卡宾及其取代物分别与苯的环加成反应具有相同的反应途径．该途径均由两步组成：（1）卡宾及其取代物分别与苯反应生成各自相应的中间体（INT），它们均为无势垒的放热反应；（2）各中间体（INT）分别又经过相应的过渡态（TS）异构化为相应的产物（P）．同时还发现，取代基的电负性和吸电子能力越大，卡宾取代物与芳香族化合物环加成反应的反应活性越小．%The mechanism of cycloaddition reactions of Benzene with singlet carbene and its substituted species were investigated using HF theory of quantum chemistry method at HF/3 -21G * level. The transition states both to the reactant and the product directions in the reaction paths were examined by using the intrinsic reaction coordinate. The results show that the cycloaddition reactions of benzene with carbene and its substituted species respectively have the same reaction paths ,which consist of two steps: ( I ) Carbene and its substituted with Benzene from respectively the each relevant intermediates(INT) respectively, which are barrier- free exothermic reactions;( U ) Each intermediates(INT) isomerizes to relevant products (P) Via relevant transition states (TS). And we find that the stronger the electron negativity and the power of pulling electron of the substituents,the smaller the reaction activity of cycloaddition reactions between the carbene substitutants and aromatic compounds.
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