Solvatochromism and Thermochromism of Fluconazole: An Experimental and Theoretical Study

Abstract

This research aims to study fluconazole (FNZ)-solvent interactions in pure solvents through theoretical and experimental solvatochromism. This study showed a bathochromic shift as the polarity of the solvent increases, where the excited state of FNZ is of higher polarity and lower energy than that of the ground state. The multiparametric statistical analysis highlighted solvent polarizability, dispersion, and electronic induction as solvent parameters of great importance, with the basicity of solvent and hydrogen bond acceptor capacity as having certain relevance. The thermochromic effect was also determined by exposing the three pKa values of FNZ. In conclusion, this study shows the importance of the π-π stacking interaction of the FNZ dihalogenated phenyl ring, the solvent basicity for the hydroxyl group, and its acidity for the N4' of one of the triazoles stand out, as well as the acid-base equilibria involving the -OH group and the two N4'.