Absorption and Emission Spectra of Anthracene-9-Carboxylic Acid in Solution Within the Polarizable Continuum Model: A Long-Range Corrected Time Dependent Density Functional Study

Abstract Using time-dependent density functional theory in combination with the polarizable continuum model (PCM), we studied the accuracy of different long-range corrected (LRC) hybrid functionals when reproducing vertical absorption and emission transition energies of the anthracene-9-carboxylic acid. To reach this goal, the optical properties of the acid in different solvents, with a broad dielectric constant range, have been calculated using four LRC functionals (LC-PBE, LC-wPBE, LC-BLYP, and CAM-B3LYP) as well as the parameter free PBE0 hybrid functional. In addition, in order to evaluate the solvent polarity and hydrogen bond interaction effects in the simulations, we have applied both implicit and mixed explicit/implicit solvent models. It has been found that the linear response (LR) PCM/CAM-B3LYP/6-311++G(d,p) level of theory provides the smallest errors with an absolute deviation of 0.05–0.09 (1.42–2.49%) and 0.01–0.06 eV (0.37–2.23%) for the S 0  → S 1 and S 1  → S 0 transition energies, respectively. The second best results were obtained with the PBE0 functional exploiting the state-specific (SS) scheme. This scheme suffers larger deviations especially for the absorption spectra (errors of ~ 7%) but appears particularly well suited for the prediction of the emission transition energies with absolute deviations between 0.01 and 0.13 eV (0.15–4.76%). PCM/PBE0 calculations including explicit acetone and ethanol molecules reproduce well the solvent effect of the hydrogen bond interaction, producing a small improvement in both LR and SS schemes. Both solvent models, using the CAM-B3LYP functional, are suitable for the correct interpretation and prediction of optical properties of 9-substituted anthracene derivatives in different solvent environments.