On-demand hydrogen production from formic acid by light-active dinuclear iridium catalysts

Light-active dinuclear iridium pentahydride complexes catalyze the decomposition of formic acid to generate H-2 by irradiation (lambda =395 nm) under ambient temperature and base-free conditions. The catalyst activity is sensitive to light producing H-2 under light irradiation, but with no reaction being observed in the absence of light or when the light is switched off, thereby demonstrating the clear ON/OFF switching ability of this system. Importantly, the dinuclear structure of the catalyst is sufficiently stable to be maintained under the catalytic conditions employed herein.