Fluorescence of aqueous sodium salicylate under U.-V. excitation

Abstract

The fluorescence of aqueous solutions of sodium salicylate was investigated in the absence and presence of quenchers (NO^–₃, I^–, Br^–, Cl^–). The absolute fluorescence yield of salicylate, ϕ_f= 0.32 ± 0.03, its natural lifetime = 32.3 ns, the Stern-Volmer constants and absolute rate constants for self-quenching and for quenching by the added solutes were obtained. The reversal of self-quenching observed¹ in more concentrated solutions is interpreted in terms of ground-state π- bonded dimer formation, as suggested also by n.m.r. results.