Fluorescence quenching of anthracene by aniline in different solvents

Received 2 September 2003; revised 9 February 2004; accepted 7 May 2004 Fluorescence quenching of anthracene by aniline in five different solvents has been carried out at room temperature with a view to understand the quenching mechanisms. Experimental results show positive deviation in the Stern-Volmer plots in all the solvents studied. In order to interpret these results the ground state complex and sphere of action static quenching models have been invoked. Using these models various rate parameters have been determined. Ground state complex formation model is found not to be applicable. Using sphere of action static quenching model various rate parameters have been determined. The magnitudes of these parameters imply that sphere of action static quenching model agrees well with the experimental results. Hence, the positive deviation in the S-V plots is attributed to the static and dynamic quenching. Further, with the use of finite sink approximation model it has been observed that these bimolecular reactions are diffusion limited. The dependence of Stern-Volmer constant on dielectric constant of the solvents suggests the charge transfer character of the excited complex.