Active repair of a dinuclear photocatalyst for visible-light-driven hydrogen production.

The molecular apparatus behind biological photosynthesis retains its long-term functionality through enzymatic repair. However, bioinspired molecular devices designed for artificial photosynthesis, consisting of a photocentre, a bridging ligand and a catalytic centre, can become unstable and break down when their individual modules are structurally compromised, halting their overall functionality and operation. Here we report the active repair of such an artificial photosynthetic molecular device, leading to complete recovery of catalytic activity.

Photocatalytic Generation of Hydrogen Using Dinuclear π-Extended Porphyrin-Platinum Compounds.

A series of heterodinuclear complexes, M-1-PtX with M=H , Zn, Cu or Co, X=Cl or I, has been synthesized, and first results on their photocatalytic activity in visible light driven proton reduction are presented. The compounds are based on a phenanthroline extended meso-tetramesityl-porphyrin bridging ligand (H -1) incorporating different metal centers in the porphyrin moiety, which functions as a photosensitizer unit. The well-known catalytically active PtX fragment resides in the phenanthroline coordination pocket.

π-Stacking attraction vs. electrostatic repulsion: competing supramolecular interactions in a tpphz-bridged Ru(ii)/Au(iii) complex.

The synthesis and characterization of a mixed metal ruthenium(ii)/gold(iii) complex bridged by tetrapyridophenazine (tpphz) are described. It is isostructural and isoelectronic to the well-known photocatalysts with palladium(ii) or platinum(ii). Concentration dependent (1)H-NMR spectroscopy and XRD studies show that the electrostatic repulsion between the gold(iii) moieties exceeds the attractive π-stacking interaction.