Anion Induced Fluorescence Quenching of Various Naphthalenediols

Fluorescence quenching of four naphthalenediols [1,5-; 1,7-; 2,7-; and 2,3- Naphthalenediols (NDs)] by inorganic anions [Cl−, Br−, SO4 2− SO3 2−, S2O3 2−, CO3 2−, NO3 −, and HPO4 2−] have been studied in 95% (v/v) water –ethanol mixture medium. The quenching was found to be dynamic in all systems. The plots of log kq values with singlet transition energy (Es) of the fluorophore and with ECTTS of the quencher are linear indicating the presence of electron transfer quenching mechanism. ΔGTH values for charge transfer quenching have been determined for naphthalenediols