An ab initio Study on the Molecular Elimination Reactions of Methacrylonitrile

摘要

Ab initio quantum chemical molecular orbital calculations have been performed for the unimolecular decomposition of methacrylonitrile (CH_3C(CN)=CH_2),especially for HCN and H_2 molecular elimination channels.Structures and energies of the reactants,products,and relevant species along the individual reaction pathways were determined by MP2 gradient optimization and MP4 single point energy calculations.Direct four-center elimination of HCN and three-center elimination of H_2 channels were identified.In addition,H or CN migration followed by HCN or H_2 elimination channels via the methylcyanoethylidene intermediate was also identified.Unlike the case of crotonitrile previously studied,in which the dominant decomposition process was the direct three-center elimination of HCN,the most important reaction pathway should be the direct three-center elimination of H_2 in the case of methacrylonitrile.