Reactions of singlet and triplet methylene with a C-H bond of ethylene. An ab initio study

The insertion reaction of singlet methylene into a C-H bond of ethylene and the hydrogen abstraction from ethylene by triplet methylene have been theoretically studied by using the 3-21G and 6-31G* basis sets and introducing electron correlation and thermodynamic corrections. The obtained results have permitted us to analyze the mechanistic differences between both processes. The competition between them and the well-known addition reactions to olefinic double bonds is also discussed. © 1988 American Chemical Society.