The Dynamics of the Reaction of FeO and H : A Model for Inorganic Oxidation.

Extensive density functional theory (DFT) calculations using the B3LYP functional were used to explore the sextet and quartet energy potential energy surfaces (PESs) of the title reaction, and as a basis to fit global analytical reactive PESs. Surface-hopping dynamics on these PESs reproduce the experimentally observed reactivity and confirm that hydrogen activation rather than spin-state change is rate-limiting at low reaction energy, where the main products are Fe and H O. A change in spin state is inefficient in the product region so that excited-state Fe is the dominant product. At higher energies, spin-allowed hydrogen atom abstraction to form FeOH predominates. At intermediate energy, a previously unexpected rebound mechanism contributes significantly to the reactivity.