NHC-Coordinated Diphosphene-Stabilized Gold(I) Hydride and Its Reversible Conversion to Gold(I) Formate with CO.

An NHC-coordinated diphosphene is employed as ligand for the synthesis of a hydrocarbon-soluble monomeric Au hydride, which readily adds CO at room temperature yielding the corresponding Au formate. The reversible reaction can be expedited by the addition of NHC, which induces β-hydride shift and the removal of CO from equilibrium through the formation of an NHC-CO adduct. The Au formate is alternatively formed by dehydrogenative coupling of the Au hydride with formic acid (HCO H), thus in total establishing a reaction sequence for the Au hydride mediated dehydrogenation of HCO H as chemical hydrogen storage material.