title: A theoretical study of crystallochromy: spectral tuning of solid-state tetracenes.
abstract: The crystallochromy of the red and yellow solids of tetracenes was theoretically investigated using the transition-density-fragment interaction combined with transfer integral method [K. J. Fujimoto, J. Chem. Phys. 137, 034101 (2012)]. The calculated absorption and fluorescence energies were in good agreement with the experimental values for both solids. The spectral tuning mechanism was analyzed in terms of three contributions: side-chain conformational effect, electrostatic solid-state effect, and multimerization effect. This analysis provided an insight into the mechanism of the large spectral shift between the two solids. The multimerization effect was found to be primarily important for the large red-shift of the red solid. Further analysis also revealed the strong dependence of the excited state character on the molecular displacement. Such dependence was found to have a significant influence on the magnitudes of the absorption energy and oscillator strength. These results indicated that the present approach is useful for analyzing and understanding the mechanism of crystallochromy.
authors.affiliation: Department of Computational Science, Graduate School of System Informatics, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan.
authors.forename: Kazuhiro J
authors.initials: KJ
authors.lastname: Fujimoto
authors.forename: Chitoshi
authors.initials: C
authors.lastname: Kitamura