Photoexcitation of europium(III) in various electrolytes: Dependence of the luminescence lifetime on the type of salts and the ionic strength

Abstract

International audienceThe fluorescence characteristics (lifetime, exci-tation and emission spectra) of aqueous solutions of Eu(III) containing various supporting electrolytes such as HCl, NaCl, LiCl, CsCl, MgCl 2 , HClO 4 and NaClO 4 have been measured. The observed lifetime variations cannot be properly described neither through the hydration sphere phenomenological approach nor through a Stern-Volmer relationship. Long-range interactions between the excited ion and solvent molecules, in addition to an outer-sphere complexation with the anions, are proposed to account for the observed variations