Photocatalytic Reduction of Artificial and Natural Nucleotide Cofactors with a Chlorophyll-Like Tin-Dihydroporphyrin Sensitizer

An efficient photocatalytic two-electron reduction and protonation of nicotine amide adenine dinucleotide (NAD+)as well as the synthetic nucleotide cofactor analogue N-benzyl-3- carbamoyl-pyridinium (BNAD+) powered by photons in the long-wavelength region of visible light ( > 610 nm ) is demonstrated for the first time. This functional artificial photosynthetic counterpart of the complete energy-trapping and solar-to-fuel conversion primary processes occurring in natural photosystem I (PS I) is achieved with a robust water-soluble tin(IV) complex of meso-tetrakis(N-methylpyridinium)-chlorin acting as the light-harvesting sensitizer ( threshold wavelength 660 nm ). Very promising conversion efficiencies, quantum yields and excellent photosensitizer stabilities are observed.