A role of solvent polarity on bimolecular quenching reactions of 3-acetyl-7-(diethylamino)-2H-chromen-2-one in binary solvent mixtures

The study on preferential salvation was carried out for the 3-acetyl-7-(diethylamino)-2H-chromen-2-one (3ADHC) molecule in different binary solvent mixtures of acetonitrile (ACN) and 1,4-dioxane (DXN) at room temperature. Further, the fluorescence quenching of 3ADHC molecule with aniline was characterized by Stem-Volmer plots which shows upward curvature from linearity in all acetonitrile/1,4-dioxane mixtures. By the make use of different quenching models, Stern-Volmer constant and various other quenching rate parameters have been determined. Efficient quenching was observed for 3ADHC. Ground state complex formation does not hold in our proximity. Quenching reactions hold within the sphere of action for 3ADHC. Diffusion limited reactions are found to be more prominent in high polarity solvent mixtures namely 100% ACN + 0% DXN, 80% ACN + 20% DXN and 60% ACN + 40% DXN. The relation between quenching constant and dielectric constant of the binary solvent mixtures have been studied. (C) 2018 Elsevier B.V. All rights reserved.