Analysis of Fluorescence Quenching for Newly Synthesized Biologically Active 3( 2H)-pyridazinone Derivative by Aniline.

Herein, we have studied the analysis of fluorescence quenching for newly synthesized biologically active 3( 2H)-pyridazinone derivative 5-(5-bromo-2-hydroxy-phenyl)-2-phenyl- 2H-pyridazin-3-one [BHP] by various concentrations of aniline using UV-Visible spectroscopy, fluorescence spectroscopy and time-correlated single photon counting technique in five different solvents namely, methanol, ethanol, propan-2-ol, dimethylsulfoxide and ethyl acetate at room temperature. The fluorescence intensity of BHP molecule decrease with increasing in the aniline concentration and it is studied using the Stern-Volmer relation. The obtained Stern-Volmer plots were found to be linear in all the five solvents. The various parameters responsible for the fluorescence quenching such as quenching rate parameters ( k ), diffusion rate parameter ( k ) and the probability of quenching per encounter ( p) were experimentally calculated in all five solvents. An activation energy of quenching ( E ) was calculated using the values of activation energy of diffusion ( E ) and p. It was found that the values of E are greater than E in all five solvents studied. Further, it is inferred that the fluorescence quenching reactions in BHP molecule are more significantly affected by activation energy processes. [ABSTRACT FROM AUTHOR]