Highly fluorescent push-pull bis-coumarinyl sulfone: Synthesis, photophysical behavior, and solvatochromic response

Abstract

In this work, 3,3′-sulfonylbis(7-(diethylamino)-2H-chromen-2-one), an effective fluorescent push-pull system, is synthesized and photophysically characterized. The donor-π–acceptor–π–donor (D–π–A–π–D) architecture of the push-pull system exhibits distinctive solvatochromic behavior that is controlled by the surrounding medium. The photophysical characteristics of the molecule were investigated in detail by means of computational and experimental techniques. A variety of solvents were used to record UV–Vis absorption and fluorescence spectra, which showed notable bathochromic alterations in response to increasing solvent polarity. The fluorescence quantum yield changed substantially with solvent polarity, indicating the maximum efficiency in nonpolar liquids. In order to forecast electronic transitions and improve the molecular shape, Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) simulations were used, offering insights into the ground and excited state behaviors. The study elucidates the relationship between solvent characteristics and the photophysical behavior of the bis-coumarinyl sulfone, offering valuable information for designing advanced fluorescent materials with adaptable photophysical properties.