Fluorescent probe 4-dimethylaminochalcone: Solvatochromism according to the data of semiempirical and quantum-chemical calculations

The solvatochromic regularities observed in solutions of 4-dimethylaminochalcone (DMCh) are investigated in terms of two independent theoretical approaches, i.e., semiempirical and quantum-chemical, and the results of these investigations are directly compared with each other for the first time. It has been shown that the values of the absolute solvation shift of the long-wavelength DMCh electronic absorption band determined by different methods are in a good quantitative agreement both with each other and with experimental data. This fact can be considered as a substantial additional justification of the conclusion on the predominantly nonspecific origin of intermolecular forces determining the mechanisms by which the DMCh fluorescent probe functions in biological systems.