화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.116, No.33, 8634-8643, 2012
Electronic Excitations in Epicocconone Analogues: TDDFT Methodological Assessment Guided by Experiment
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-zeta 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.