Highly Efficient Photocatalytic Water Reduction with Robust Iridium(III) Photosensitizers Containing Arylsilyl Substituents

Waterproof complexes: Cationic Ir(III) photosensitizers (PSs) with an ancillary 4,4'-bis(4-(triphenylsilyl)phenyl)-2,2'-bipyridine ligand enabled hydrogen evolution from water with high turnover numbers (TONs; see scheme). The peripheral triphenylsilyl moieties prevent ligand substitution by solvent molecules, such as water, and thus increase the durability of the complexes. SR=sacrificial reducing agent, WRC=water-reduction catalyst.