甲基乙基亚硫酸与亚氨基负离子多组分反应及机理的理论研究

Study on themulti-component reaction and mechanism of methylethyl sulfite and iminium anion

采用分子动力学方法研究了一系列同比例(5:5,10:10,20:20,50:50)和不同比例(20:30,20:40,20:50和30:20,40:20,50:20)的亚氨基负离子与甲基乙基亚硫酸的反应显示,有较多的亚氨基转化为氨气,同时甲基乙基亚硫酸分解为甲醇、乙醇和一些小的碳化合物等物质.通过密度泛函的B3lyp和Bhandhlyp两种方法,在6-311++G(3df,3pd)水平下对其反应机理进行研究表明,此反应为多通道多步骤的反应体系,无论主反应还是次反应均为放热反应,其中生成产物为P1(CH_(3)OSO_(2)^(-)+NH_(3)+C_(2)H_(4)),P2(CH_(3)OSO_(2)^(-)+NH_(2)CH_(2)CH_(3)),P3(CH_(2)O+SO_(2)+NH_(3)+C_(2)H_(5)^(-))的路径为最佳反应通道,而生成P4(CH_(3)NH_(2)-+CH_(3)CH_(2)OSO_(2))和P5(CH_(3)-+NH_(3)+SO_(2)+CH_(3)CHO)次之,均在实验上是可检的.产物P6(CH_(3)CH_(2)OH+NSO-+CH_(2)OH),P7(CH_(2)O+NH_(3)+CH_(3)CH_(2)OSO)和P8(CH_(3)CHO+NH_(3)+CH_(3)OSO)的生成过程因存在较高势垒,为标题反应的次要路径.理论计算结果与实验一致.

The reactions of a series of iminium anions with methylethyl sulfite in some same ratios(5:5,10:10,20:20,50:50)and in different ratios(20:30,20:40,20:50 and 30:20,40:20,50:20)were studied by molecular dynamics methods,the results showed that a higher amount of iminium was converted to ammonia,while methyl ethyl sulfite was decomposed into substances such as methanol,ethanol and some small carbon compounds.The study of the reaction mechanism at the level of 6-311++G(3df,3pd)by both B3lyp and Bhandhlyp of density flooding showed that this reaction is a multi-channel and multi-step reaction system,and both the primary and secondary reactions are exothermic,in which the paths that the products produced are P1(CH_(3)OSO_(2)^(-)+NH_(3)+C_(2)H_(4)),P2(CH_(3)OSO_(2)^(-)+NH_(2)CH_(2)CH_(3)),and P3(CH_(2)O+SO_(2)+NH_(3)+C_(2)H_(5)^(-))are the best reaction channels,while the generation of P4(CH_(3)NH_(2)-+CH_(3)CH_(2)OSO_(2))and P5(CH_(3)-+NH_(3)+SO_(2)+CH_(3)CHO)are the next best,all of which are experimentally detectable.The production processes of products P6(CH_(3)CH_(2)OH+NSO-+CH_(2)OH),P7(CH_(2)O+NH_(3)+CH_(3)CH_(2)OSO)and P8(CH_(3)CHO+NH_(3)+CH_(3)OSO)are secondary pathways of the title reaction due to the presence of higher potential barriers.The results of the theoretical calculations agree with the experimental results.