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 H2production 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 H2release nearly reaches unity as the concentration of 1 increases. This unique pathway for photochemical H2generation provides insight into transformations catalyzed by 1.
Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Matthew B
MB
Chambers
Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Daniel A
DA
Kurtz
Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Catherine L
CL
Pitman
Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
M Kyle
MK
Brennaman
Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Alexander J M
AJ
Miller