乙烯基炔与一氧化氮反应机理的理论探讨

利用半经验AM1方法，研究了乙烯基乙炔与一氧化氮反应生成丙炔腈（反应1）和丙烯腈（反应2）的两条竞争反应途径．采用Berny梯度法优化得到了反应势能面上的所有驻点，并逐一进行了振动分析确认．结果表明，反应互较反应Ⅱ易引发（即；NO比较容易与乙烯基乙炔进行分步的1，4-加成，形成六元环过渡态及中间体，最终消除CH2O和H自由基后生成丙炔腈），而反应Ⅱ较难引发（NO与乙烯基乙炔较难进行1，2-加成，形成四元环过渡态及中间体），但一经引发，就能较容易地进行分步裂解，生成丙烯腈和CHO自由基．

AM1 Studies of Two Pathways of Vinylacetylene React with Nitric Oxide

Two competitive pathways of the stepwise reaction of vinyl acetylene (VA) with nitric oxide were studied by UAM1 method. The calculations showed that the path Ⅰ(NO attacks VA to form a six-membered cyclic transition state through the 1,4-addition reaction for the first two steps, then decomposed at the last two steps to form CH2O, propionitrole and H ratical) is easier to initiate than path Ⅱ(NO approaches VA with a 1.2-addition to form a four-membered cyclic transition state at its first two steps). However, path Ⅱcall easily take place at its final two steps to form acrylonitrile once it has been initiated.