title: 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.
authors.affiliation: Theoretical Chemistry Group, UMR CNRS 6014 and FR 3038, Université de Rouen et INSA de Rouen, F-76821 Mont St. Aignan Cedex, France.
authors.forename: Olga A
authors.initials: OA
authors.lastname: Syzgantseva
authors.forename: Vincent
authors.initials: V
authors.lastname: Tognetti
authors.forename: Laurent
authors.initials: L
authors.lastname: Joubert
authors.forename: Agathe
authors.initials: A
authors.lastname: Boulangé
authors.forename: Philippe A
authors.initials: PA
authors.lastname: Peixoto
authors.forename: Stéphane
authors.initials: S
authors.lastname: Leleu
authors.forename: Xavier
authors.initials: X
authors.lastname: Franck
mesh_terms: D001578:Benzopyrans / Q000737:chemistry*; D004583:Electrons; D005663:Furans / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D001578:Benzopyrans; D005663:Furans; D007659:Ketones; C477464:epicocconone