The roles of the first and second coordination spheres in the design of molecular catalysts for H2 production and oxidation.

This tutorial review describes the development of discrete transition metal complexes as electrocatalysts for H2 formation and oxidation. The approach involves the study of thermodynamic properties of metal hydride intermediates and the design of ligands that incorporate proton relays. The work is inspired by structural features of the H2ase enzymes and should be of interest to researchers in the areas of biomimetic chemistry as well as catalyst design and hydrogen utilization.