Enhancement of magnetic field effect in Ru(bpy)32+/MV2+ system by Ru(bpy)32+-Ag+ exciplex formation

Abstract The influence of ionic strength variation and of exciplex formation between silver ions and triplet excited RuL 3 2+ (L=bipyridine, phenanthroline) on the photo electron transfer kinetics of the complex with methylviologen and the magnetic field dependence of free radical formation efficiency has been studied by laser flash spectroscopy. The magnetic field effect consisting in a decrease of the efficiency of cage escape η ce in the Ru(bpy) 3 2+ /MV 2+ system is enhanced by 40% when exciplex formation between Ag + ions and triplet excited RuL 3 2+ complexes takes place. The relevant kinetic parameters have been determined by magnetokinetic model calculations.