Catalytic hydrogenolysis of alkyl halides by sulfido-bridged molybdenum clusters: A density functional study by McGrady, J, Gracia, J

“…The addition occurs across a single Mo-S bond, and the disruption of the strong Mo-S π bonding in the ground state leads to a very high-lying transition state (+43 kcal mol-1). Once formed, the adsorbed hydrogen migrates over the cluster via a series of hops from metal to sulphur, formally corresponding to a switch from hydridic to protic character. …”