Theoretical study of lumichrome, 1-methyl-lumichrome and lumiflavin binding ability with thymine

Gas-phase geometry and electronic structure of lumichrome, 1-methyl-lumichrome and lumiflavin in the electronic ground state and their excited states were investigated using the Density Functional Theory. Their binding ability with thymine was estimated for model van der Waals dimers with two intermolecular hydrogen bonds. The influence of hydrogen bonds on their photophysical properties was analyzed. Obtained theoretical data were compared with available experimental absorption and fluorescence spectra.