CH3与NO在单、三态势能面上的反应机理

用从头算分了轨道法，在ＵＨＦ／６－３１Ｇ，水平上研究了ＣＨ３Ｏ与ＮＯ在单、三态势能面上的反应机理，发现该反应在两个势能面上均在两个彼此平行的反应途径，分别生产成产物ＣＨ３ＯＮ（ａ）和ＨＣＨＯ＋ＨＮＯ（ｂ），优化了四个途径的所有驻点的几何构型，用Ｍｏｒｏｋｕｍａ的数值分析方法计算了它们的内禀反应坐标（ＩＲＣ），各途径经零点能（ＺＰＥ）校正的活化位垒，单重态途径（ａ）为８６．８６ｋＪ．ｍｏｌ＾－１途径

Theoretical Study on the Singlet-state and the Triplet-state Mechanisms for the Reaction CH_3O with NO

Ab initio UHF/6-31G** method have been used to study the reaction mechanism of CH3O with NO on the singlet and triplet potential energy surfaces. Two parallel reaction channels, leading to products CH3ONO(a) and HCHO HNO(b), were separately found on these potential energy surfaces. The Intrinsic Reaction Coordinates (IRC) for the above reactions were traced by using the algorithm of Morokuma. The activation barriers at 6-31G** ZPE level are 86-86 kJ.mol-1 and 159.22 kJ.mol-1 respectively for path(a) and path(b) on the singlet-state surface, and 139.20 kJ.mol-1 and 196.49 kJ.mol-1 repectively on the triplet-state suxface. The theoretical results show that the reaction occurs more favorably on the singlet-state surface and that CH3ONO is predominately produced than other products, which is in agreement with the experimental result.