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.