Mechanistic insight into proton-coupled mixed valency

Abstract

Stabilisation of the mixed-valence state in [Mo₂(TiPB)₃(HDOP)]₂⁺ (HTiPB = 2,4,6-triisopropylbenzoic acid, H₂DOP = 3,6-dihydroxypyridazine) by electron transfer (ET) is related to the proton coordinate of the bridging ligands. Spectroelectrochemical studies suggest that ET is slower than 10⁹ s⁻¹. The mechanism has been probed using DFT calculations, which show that proton transfer induces a larger dipole in the molecule resulting in ET.