Luminescence quenching of [Os(bpy)<inf>3</inf>]²⁺by Mn⁷⁺, Cr⁶⁺and Ce⁴⁺ions in acidic aqueous solution

Abstract

Luminescence quenching of [Os(bpy)3]2+by Mn7+, Cr6+and Ce4+ions in acidic aqueous media are studied. Ground state interactions between [Os(bpy)3]2+and these ions show ground state association with stoichiometric ratios in accordance with the electron transfer process. Positive deviation is observed from the linear Stern-Volmer relationship which with the ground state association is in support of static quenching mechanism. Benesi-HildEbrand equation was used to evaluate the association constant which were found to be 5×103M-1, 6.6×104M-1and be 1.1×105M-1for association of [Os(bpy)3]2+with Ce4+, Cr6+and Mn7+, respectively, based on luminescence intensity measurements. Different models for static luminescence quenching were employed to discuss the results. © 2014 Elsevier B.V.