Theoretical investigations of the UV spectra of coumarin derivatives

The UV absorption spectra of substitued coumarins have been investigated with a wide panel of theoretical methods. In the density functional theory framework (DFT), various basis sets, as well as several functionals have been tested. It turns out that the Becke-Lee-Yang-Parr functional (B3LYP), combined with the 6-311+G(2d,2p) atomic basis set, provides reliable λmax when the solvent effects are included in the model.