Theoretical Investigation of Steric and Electronic Effects of meso-Phenyl on Co-Porphyrin Catalyzed Activation of Dioxygen

Abstract

The molecule oxygen (O₂) activated on cobalt tetraphenylporphyrin (CoTPP) to form the peroxide species CoTPPO₂, which is the key intermediate in the behavior of metalloporphyrin catalyzed hydrocarbon oxidation, was simulated by the quantum chemical calculations. The effect of the meso-phenyl ring on the formation of the peroxide species CoTPPO₂ was investigated for the first time. The molecular geometry studies indicated that the meso-phenyl ring rotated with the molecule oxygen coordinated with CoTPP. Further nature atomic charge and nature bond orbital analysis supported that the steric changing of the meso-phenyl has a positive effect on the electron transport between CoTPP and O₂ to from the peroxide intermediate.