Solvent effect on the fluorescence quenching of biologically active carboxamide by aniline and carbon tetrachloride in different solvents using S-V plots

► Stern-Volmer plots show positive deviation, indicating efficient fluorescence quenching. ► Static quenching constant 'V' and kinetic distance 'r' are in agreement with literature values. ► Values of kq are greater than 4πN′R′D, which is expected result for diffusion limited reaction. ► Finite sink approximation model is valid in recovering the parameters D and R′ (R). ► Quenching reaction is diffusion limited, both static and dynamic quenching processes are playing a role.