HIGH PHOTOREDUCTION YIELD OF EU3+ TO EU2+ IN ALCOHOLIC SOLUTIONS AND ITS WAVELENGTH DEPENDENCE

Photoreduction yields of Eu3+ to Eu2+ in aqueous and alcoholic solutions were determined. The highest quantum yields were found to be 0.97 +/- 0.16 for EuCl3 in methanol under 308 nm excitation and 0.94 +/- 0.17 in 2-propanol under 248 nm excitation. The lowest quantum yield was 0. 12 +/- 0.02 for Eu(ClO4)3 in aqueous solution under 193 nm excitation. The high photoreduction yields for EUCl3 indicate that Cl. reacts efficiently with neighbouring alcohols. The yield was found to depend on the excitation wavelength for EuCl3 in methanol solution.