Reaction pathways of singlet silylene and singlet germylene with water, methanol, ethanol, dimethyl ether, and trifluoromethanol: An ab initio molecular orbital study

Ab initio molecular orbital calculations have been performed to explore the reaction potential energy surfaces of singlet silylene and germylene with water, methanol, ethanol, dimethyl ether, and trifluoromethanol. We have id entified two new reaction channels on each reaction surface, except for rea ctions involving dimethyl ether. The previously unreported reaction channel s involve H-2 elimination following the initial formation of an association complex. For reactions involving singlet silylene and water, a simple acti vated complex theory (ACT) analysis predicts that these newly identified re action channels are equally likely to be accessed as the previously identif ied 1,2 hydrogen atom shift channels. For reactions involving singlet germy lene and water, a similar ACT analysis predicts that the H-2-elimination ch annels will occur in preference to the 1,2 hydrogen shift. Indeed, the room -temperature rate constants for H-2 elimination from the germanium complex are predicted to be approximately 5 orders of magnitude greater than for th e H atom migration channel.