부산대학교 도서관

Three platinum(II) terpyridylacetylide charge-transfer complexes possessing a lone ancillary ligand systematically varied in phenylacetylide π-conjugation length, [Pt(tBu3tpy)([CCC6H4]nH)]ClO4(n= 1−3), are evaluated as photosensitizers (PSs) for visible-light-driven (λ > 420 nm) hydrogen production in the presence of a cobaloxime catalyst and the sacrificial electron donor triethanolamine (TEOA). Excited-state reductive quenching of the PS by TEOA produces PS−(kqscales with the driving force as 1> 2> 3), enabling thermal electron transfer to the cobalt catalyst. The initial H2evolution is directly proportional to the incident photon flux and visible-light harvesting capacity of the sensitizer, 3> 2> 1. The combined data suggest that PSs exhibiting attenuated bimolecular reductive quenching constants with respect to the diffusion limit can overcome this deficiency through improved light absorption in homogeneous H2-evolving compositions.