Reaction of 3d Transition Metal Hydride Cations with Co2

Quantum chemical calculations were conducted to study reactions between cationic 3d transition metal hydride and carbon dioxide. The calculated results reveal that there are mainly-two reaction channels, which are to form HCOO-; (Path A) and [M(CO)(OH)](+) (Path B), respectively. Path A is always kinetically more favorable than Path B except for Zn. However, only Path A of Sc-Cr could occur under ambient conditions in the gas phase. According to the analyses of charges and spin populations along the reaction pathways, Path A was found to be a hydride transfer mechanism, and Path B is a hydrogen atom transfer mechanism except for Zn, which should be a proton-coupled electron transfer mechanism.