A cobalt(II) quaterpyridine complex as a visible light-driven catalyst for both water oxidation and reduction

The complex [Co-II(qpy)(OH2)(2)](2+) (qpy = 2,2': 6',2 '': 6 '',2'''-quaterpyridine) is an efficient visible light-driven catalyst for both water oxidation and reduction. It catalyses photochemical oxygen evolution from water at pH 8.0 with [Ru-II(bpy)(3)](2+)/S2O82- (lambda = 457 nm, max TON = 335, bpy = 2,2'-bipyridine). It also catalyses photochemical hydrogen generation from [Ir-III(dF(CF3)ppy)(2)(dtbbpy)](+)/TEOA (dF(CF3)ppy = anion of 2-(2,4-difluorophenyl)-5-tri-fluoromethylpyridine, dtbbpy - 4,4'-di-tert-butyl-2,2'-bipyridine, TEOA = triethanolamine) in aqueous acetonitrile (lambda > 420 nm, max TON = 1730).