SIMULTANEOUS PRESENCE OF STATIC AND DYNAMIC COMPONENT IN THE FLUORESCENCE QUENCHING FOR SUBSTITUTED NAPHTHALENE-CCL4 SYSTEM

The fluorescence quenching of some substituted naphthalenes by chlorom ethanes such as carbontetrachloride (CCl4) have been studied in a larg e number of solvents at room temperature. The quenching is found to be appreciable and a positive deviation from linearity was observed in t he Stern-Volmer (SV) plot for all the fluorophores in all the solvents even at moderate CCl4 concentration (0.1 M). From the studies of effe ct of temperature, solvent viscosity and lifetime measurements it coul d be explained that the non-linearity is due to the presence of a smal l static quenching component in the overall dynamic quenching. The sta tic (K-S) and dynamic (K-D) quenching constants are calculated using t he extended Stern-Volmer equation.