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

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 5×103 M−1, 6.6×104 M−1 and be 1.1×105 M−1 for 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.