Efficient Photochemical Dihydrogen Generation Initiated by a Bimetallic Self-Quenching Mechanism.
Artificial photosynthesis relies on coupling light absorption with chemical fuel generation. A mechanistic study of visible light-driven H2 production from [Cp*Ir(bpy)H]+ (1) has revealed a new, highly efficient pathway for integrating light absorption with bond formation. The net reaction of 1 with a proton source produces H2, but the rate of excited state quenching is surprisingly acid-independent and displays no observable deuterium kinetic isotopic effect. Time-resolved photoluminescence and labeling studies are consistent with diffusion-limited bimetallic self-quenching by electron transfer. Accordingly, the quantum yield of H2 release nearly reaches unity as the concentration of 1 increases. This unique pathway for photochemical H2 generation provides insight into transformations catalyzed by 1.
Publication Source (Journal or Book title)
Journal of the American Chemical Society
Chambers, M. (2016). Efficient Photochemical Dihydrogen Generation Initiated by a Bimetallic Self-Quenching Mechanism.. Journal of the American Chemical Society https://doi.org/10.1021/jacs.6b08701