Electronic structure considerations for methane activation by third-row transition-metal ions

Abstract

Methane is spontaneously dehydrogenated in the gas phase by many metal ions of the 5d transition series. In most cases, the MCH{sub 2}{sup +} produced undergoes further reactions, leading eventually to products such as WC{sub 8}H{sub 16}{sup +}. The reactivity of the third-row transition-metal ions, both bare and with simple ligands, may be explained in terms of electronic structure considerations. Promotion energy, exchange energy, and the relative and absolute sizes of the valence s and d orbitals all appear to be important.