Off-Set Interactions of Ruthenium-bda Type Catalysts for Promoting Water-Splitting Performance.

ABSTRACT: O-O bond formation with Ru(bda)L₂ -type catalysts is well-known to proceed through a bimolecular reaction pathway, limiting the potential application of these catalysts at low concentrations. Herein, we achieved high efficiencies with mononuclear catalysts, with TOFs of 460±32 s^-1 at high catalyst loading and 31±3 s^-1 at only 1 μM catalyst concentration, by simple structural considerations on the axial ligands. Kinetic and DFT studies show that introduction of an off-set in the interaction between the two catalytic units reduces the kinetic barrier of the second-order O-O bond formation, maintaining high catalytic activity even at low catalyst concentrations. The results herein furthermore suggest that π-π interactions may only play a minor role in the observed catalytic activity, and that asymmetry can also rationalize high activity observed for Ru(bda)(isoq)₂ type catalysts and offer inspiration to overcome the limitations of 2nd order catalysis.

SUBMITTER: Timmer BJJ 

PROVIDER: S-EPMC8251529 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature