Experimental and theoretical study on solvent and substituent effect in 3-(4-substituted)phenylamino)isobenzofuran-1(3H)-ones

Abstract

The substituent and solvent effects on solvatochromism in 3-[(4-sub­stituted)phenylamino]isobenzofuran-1(3H)-ones were studied using exper­i­mental and theoretical methodologies. The effect of specific and non-specific solvent–solute interactions on the shifts of UV–Vis absorption maxima were evaluated using the Kamlet–Taft and Catalán solvent parameter sets. The expe­rimental results were studied by density functional theory (DT) and time-dep­endent density functional theory (TD-DFT). The HOMO/LUMO energies (EHOMO/ELUMO) and energy gap (Egap) values, as well as the mechanism of electronic excitations and the changes in the electron density distribution in both ground and excited states of the investigated molecules were studied by calculation in the gas phase. The electronic excitations were cal­culated by the TD-DFT method in the solvent methanol. It was found that both substituents and solvents influence the degree of π-electron conjugation of the synthesized molecules and affect the intramolecular charge transfer character.