Electronic excitations in epicocconone analogues: TDDFT methodological assessment guided by experiment.

Abstract

In this work we present a combined theoretical and experimental study of UV/vis absorption spectra of novel organic chromophores derived from epicocconone. A computational protocol, consistent with experimental findings, is proposed in the framework of time-dependent density functional theory. More precisely, the influence of density functional, basis set, and solvation effects is assessed through theory-experiment matching. On the one hand, it is shown that global hybrid functionals fail to describe excitation spectra for the whole training set. On the other hand, range-separated hybrids allow a description of the complete set of epicocconone derivatives on equal footing, while the double-ζ basis set is shown to be sufficiently accurate for the screening of the spectroscopic properties in epicocconone analogues. The inclusion of solvent effects within a polarizable continuum model appears to be compulsory to decrease the residual dispersion. State specific solvation, on the contrary, does not provide a significant consistency/accuracy improvement. Besides, conformational transformations in investigated compounds and their influence on electronic absorption spectra are pointed out. A systematic choice of the same conformation for each compound from the training set enhances consistency and accuracy of our theoretical model. Lastly, a TDDFT-based calibration is proposed for prediction of absorption wavelengths in epicocconone analogues.

DOI: 10.1021/jp305269y

Cite this paper

@article{Syzgantseva2012ElectronicEI, title={Electronic excitations in epicocconone analogues: TDDFT methodological assessment guided by experiment.}, author={Olga A. Syzgantseva and Vincent Tognetti and Laurent Joubert and Agathe Boulang{\'e} and Philippe A Peixoto and St{\'e}phane Leleu and Xavier Franck}, journal={The journal of physical chemistry. A}, year={2012}, volume={116 33}, pages={8634-43} }