Thermal Activation of Methane by [HfO](center dot+) and [XHfO](+) (X = F, Cl, Br, I) and the Origin of a Remarkable Ligand Effect

摘要

The thermal reactions of methane with [HfO](center dot+) and [XHfO](+) (X = F, Cl, Br, I) were investigated by using FT-ICR mass spectrometry complemented by high-level quantum chemical calculations. Surprisingly, in contrast to the inertness of [HfO](center dot+) towards methane, the closed-shell oxide ions [XHfO](+) (X= F, Cl, Br) activate the H3C-H bond to form the insertion products [Hf(X)(OH)(CH3)](+). The possible origin of this remarkable ligand effect is discussed.