Metal- and ligand-substitution-induced changes in the kinetics and thermodynamics of hydrogen activation and hydricity in a dinuclear metal complex.

Catalytic function in organometallic complexes is achieved by carefully selecting their central metals and ligands. In this study, the effects of a metal and a ligand on the kinetics and thermodynamics of hydrogen activation, hydricity degree of the hydride complex, and susceptibility to electronic oxidation in bioinspired NiFe complexes, [Ni II X Fe II (Cl)(CO)Y] + ([NiFe(Cl)(CO)] + ; X = N , N '-diethyl-3,7-diazanonane-1,9-dithiolato and Y = 1,2-bis(diphenylphosphino)ethane), were investigated. The density functional theory calculations revealed that the following order thermodynamically favored hydrogen activation: [NiFe(CO)] 2+ > [NiRu(CO)] 2+ > [NiFe(CNMe)] 2+ ∼ [PdRu(CO)] 2+ ∼ [PdFe(CO)] 2+ ≫ [NiFe(NCS)] + . Moreover, the reverse order thermodynamically favored the hydricity degree.