Photocatalytic H2 evolution from water based on cyclometalated platinum(II) complex

Cyclometalated platinum(II) complex, [ClPt(C^N^NPhMe)] (1) (HC^N^NPhMe = 4-(p-tolyl)-6-phenyl-2,2′-bipyridine) was found to be an efficient photosensitizer for photocatalytic hydrogen evolution from water, 98 turnovers of hydrogen were obtained after 10 h irradiation of solution containing MV2+ (4,4′-dimethyl-2,2′-bipyridinium), triethanolamine (TEOA), photosensitizer and colloidal Pt, which is far effective than that of platinum(II) terpyridyl complex [ClPt(N^N^NPhMe)]ClO4 (2) (N^N^NPhMe = 4′-(p-tolyl)-2,2′:6′,2″-terpyridine). Net photocatalytic reduction of MV2+ by the complexes in the presence of TEOA in CH3CN/H2O solvents were observed and compared upon irradiation (λ > 400 nm).