Theoretical investigation of substituted anthraquinone dyes.

We have investigated with computational chemistry techniques the visible spectra of substituted anthraquinones. A wide panel of theoretical methods has been used, with various basis sets and density functional theory (DFT) functionals, in order to assess a level of theory that would lead to converged excitation energies. It turns out that the hybrid Becke-Lee-Yang-Parr and Perdew-Burke-Erzenrhof functionals with the 6-31G (d,p) atomic basis set provide reliable lambda(max) when the solvent effects are included in the model. Combining the results of both DFT schemes allows the prediction of lambda(max) with a standard deviation limited to 13 nm.