Nature of the influence of a solvent on the fluorescence quantum yield of solutions of the fluorescent probe 4-dimethylaminochalcone

The fluorescence quantum yields of solutions of 4-dimethylaminochalcone (DMC) in a series of individual solvents of different chemical nature have been measured using a technique based on studying the kinetics of fluorescence decay. A new quantitative regularity, namely, the dependence of the fluorescence quantum yield on the absolute solvation shift in the fluorescence spectrum due to the gas-solution phase transition, has been revealed. The opinion has been advanced and justified that the revealed regularity has a fundamental character, which is determined by the dominant contribution from the universal intermolecular interactions to the formation of the properties of the solvated DMC molecule in the excited electronic state.