CO2 reduction or HCO2− oxidation? Solvent-dependent thermochemistry of a nickel hydride complex

Abstract

The hydricity (ΔG_H⁻) of a newly synthesized nickel hydride was experimentally determined in acetonitrile (50.6 kcal mol⁻¹), dimethyl sulfoxide (47.1 kcal mol⁻¹), and water (22.8 kcal mol⁻¹). The hydricity values indicate hydride transfer from [HNi(TMEPE)₂][BF₄] (TMEPE = 1,2-bis[di(methoxyethyl)phosphino]ethane) to CO₂ is exergonic in water and endergonic in the organic solvents.