Enhancement of magnetic field effect in Ru(bpy)(3)(2+)/MV2+ system by Ru(bpy)(3)(2+)-Ag+ exciplex formation

The influence of ionic strength variation and of exciplex formation between silver ions and triplet excited RuL32+ (L = bipyridine, phenanthroline) on the photo electron transfer kinetics of the complex with methylviologen an d the magnetic field dependence of free radical formation efficiency has be en studied by laser flash spectroscopy. The magnetic field effect consistin g in a decrease of the efficiency of cage escape eta(ce) in the Ru(bpy)(3)( 2+)/MV2+ system is enhanced by 40% when exciplex formation between Ag+ ions and tripler excited RuL32+ complexes takes place. The relevant kinetic par ameters have been determined by magnetokinetic model calculations. (C) 2000 Elsevier Science B.V. All rights reserved.