Hydrogen activation by unsaturated mixed-metal cluster complexes: New directions

There has been a renewed interest in the chemistry of hydrogen as a result of the ever-increasing global demands for energy. Recent studies have revealed new electronically unsaturated polynuclear metal complexes containing bulky ligands that exhibit a variety of reactions with hydrogen, including facile addition and elimination under mild conditions. Materials and molecules that can reversibly absorb large quantities of hydrogen are very attractive for hydrogen storage and hydrogenation catalysis. This Minireview summarizes recent studies of reactions of hydrogen with unsaturated mixed-metal cluster complexes containing platinum and bulky phosphine ligands. Some related studies on bimetallic cooperativity and the synthesis of trimetallic nanoparticles on mesoporous supports that exhibit high activity and selectivity for catalytic hydrogenations are also discussed.