NEW CARBANIONIC PHOTOGALVANIC CELL

Cyclooctatetraenyl dianion 1 has been shown to function as a electron source when excited with visible light at the surface of a TiO2 semiconductor electrode in a liquid NH3 photoelectrochemical cell. Since the conduction band of TiO2 in ammonia is located below the oxidation potential of 1 (disodium or -potassium salts of cyclooctatetraene) at -0.55 eV vs. Ag, the efficiency of the photoinduced electron transfer may rely on high-lying surface states, kinetic retardation of electron exchanges at the ammonia-semiconductor interface, or on other relaxation phenomena. © 1979 American Chemical Society.