LUMINESCENCE QUENCHING OF THE BIS(2,2'-BIPYRIDINE)AQUO-2,2'-BIPYRIDINEIRIDIUM(III) ION AND ITS CONJUGATE BASE

Quenching of Ir(bpy)2(H2O)(bpy)3+ and Ir(bpy)2(OH)(bpy)2+ by a variety of charged metal complexes and neutral biacetyl has been studied. Stern-Volmer and quenching constants have been determined and diffusional rate constants for each donor-acceptor combination have been estimated. Quenching efficiencies are comparable to those of Ru(bpy)32+ with similar quenchers. Quenching is believed to occur by both energy-transfer and electron-transfer mechanisms. The reduction potential of the luminescent state of lr(bpy)2(OH)(bpy)2+ is estimated to be +1.84 V. © 1979, American Chemical Society. All rights reserved.