Dimeric and trimeric states of the fluorescein dianion. Part 2.—Effects on fluorescence characteristics

Abstract

The fluorescence quenching of the fluorescein dianion in aqueous solution is studied over a wide concentration range (5 × 10^–6 to 3 × 10^–1 mol dm^–3) where aggregates are formed. The rate constants at different temperatures and the mechanisms of the quenchings produced by the monomer, dimer and trimer are determined. Some aspects relating to the nature of binding in the aggregates are clarified by the determination of the enthalpy of trimer formation.