Molecular Dyad vs Multi‐Component Approach‐Photocatalytic Hydrogen Evolution by Combining Oligothiophene Photosensitizers with [FeFe]‐Hydrogenase Mimics

Abstract

AbstractA molecular dyad (PS‐CAT) consisting of a metal‐free photosensitiser (PS) and a [FeFe]‐hydrogenase‐inspired [Fe2S2] cluster (CAT) has been synthesized for hydrogen evolution under visible light irradiation. The electrochemical properties of PS‐CAT in the absence and presence of acid were investigated by CV and IR‐SEC. The ground state and excited state photophysical properties of PS and PS‐CAT, and the non‐chemically connected reference system [PS, CAT] were investigated to elucidate the effect of a covalent linkage between PS and CAT on the electronic communication and hence on the catalytic performance. The photo‐relaxation pathway of PS‐CAT was revealed computationally by scalar‐relativistic time‐dependent density functional theory simulations. These studies are complemented by comparative analyses of photocatalytic hydrogen evolution between PS‐CAT and [PS, CAT] under visible light irradiation.