Electronic structure of merocyanine dyes derived from 3H-indole and malononitrile in the ground and excited states: DFT/TD-DFT analysis

Publication date: Available online 16 March 2019Source: Computational and Theoretical ChemistryAuthor(s): Andrii V. Kulinich, Alexander A. IshchenkoAbstractThe electronic structure and spectral-fluorescent properties of vinylogous positively solvatochromic merocyanines have been studied within the four-level scheme of electronic states using the DFT and TD-DFT computations. The calculations with the solvation taken into account have allowed us to interpret some non-trivial aspects of the merocyanine solvatochromism: weakening of the solvent influence in the fluorescent state, dependence of the shape and width of the spectral bands on the dye structure and environment polarity. It is found that the TD-DFT calculations of the higher electronic transitions agree well with the data obtained from the fluorescence excitation anisotropy spectra.Graphical abstract

Source: Computational and Theoretical Chemistry - March 18, 2019 Category: Chemistry Source Type: research