Theoretical Study of the Oxidative Addition of 16-Electron d4 [n]-Metallocenophane Complexes with Methane

We have chosen eight [n]-metallocenophane complexes to investigate the oxidative additions with methane using the B3LYP/LANL2DZ level of theory. Considering the effects from the geometry and the nature of the metal center, the following conclusions emerge: the less bent 16-electron [n]-metallocenophane complex with the transition metal center W should be a potential model for the oxidative addition of saturated C−H bonds. Our model calculations suggest that a methane σ-complex intermediate formed between the [n]-metallocenophane and methane plays a major role in the oxidative additions. Moreover, we show that both electronic and geometric effects play a significant role in determining the energy barriers.