Ground and excited states calculations of 7-phenylamino-substituted coumarins

A theoretical calculation of the ground and first excited states of two 7-phenylamino-substituted coumarin compounds are performed. In order to study the effect of phenyl substituted in amino group and fluorine atoms substituted in methyl group, 7-amino-4-methyl coumarin (C120) and 7-amino-4-(trifluoromethyl) coumarin (C151) were also studied. The geometries of the ground state and the first ground state were optimized using density function theory and configuration interaction singles levels of theory. Molecular orbitals (MO) of the ground and first excited states of the four coumarin compounds were obtained to explain the change of the structures. ZINDO and TD-DFT methods with different basis sets were applied to predict the UV absorption spectra. The solvent effect had also been taken into account using self-consistent isodensity polarized continuum model. The predicted spectra are in agreement with the experimental data.