Single-Layer Electroluminescent Devices and Photoinduced Hydrogen Production from an Ionic Iridium(III) Complex

We report the electronic structure and diverse applications of a highly luminescent ionic transition metal complex, Ir(dF(CF3)ppy)2(dtbbpy)(PF6) (where dF(CF3)ppy = 2-(2,4-difluorophenyl)-5-trifluoromethylpyridine and dtbbpy = 4,4‘-di-tert-butyl-2,2‘-dipyridyl). The large HOMO−LUMO gap (ΔE = 3.06 V) enabled high-energy electroluminescence from the complex. Single-layer devices were fabricated and found to emit blue-green light (500 nm). The strong reducing strength of the excited state (E*ox = 1.21 V) enabled effective catalysis of the photoinduced reduction of H2O to H2. It was found that the relative quantum yield of hydrogen was over an order of magnitude improved from the standard photosensitizer Ru(dmphen)32+ (dmphen = 4,7-dimethyl-1,10-phenanthroline).