ИСТИНА

Nile Red dye (NR) exhibits a pronounced vibronic structure of absorption and emission spectra in nonpolar solvents. This structure can be simulated using either a direct method based on the cumbersome summation of Franck-Condon factors [1, 2] or a mathematically equivalent but computationally more elegant time-dependent formalism [3, 4]. Here, the vibronic structure of the Nile Red spectra is simulated using the latter approach based on the displaced multi-mode harmonic oscillator approximation for the ground- and excited-state potential energy surfaces (PES) obtained from first-principle calculations according to the general methodology developed in [5, 6]. The bandshape of the theoretical spectra is studied using different DFT schemes, basis sets, and solvent models. The emission band is studied only for the locally-excited state, for which the harmonic model can be applied. References: [1] F. Santoro, R. Improta, A. Lami, J. Bloino, V. Barone, J. Chem. Phys. 2007, 126, 084509; F. Santoro, R. Improta, A. Lami, V. Barone, J. Chem. Phys. 2007, 126, 184102; F. Santoro, R. Improta, A. Lami, J. Bloino, V. Barone, J. Chem. Phys. 2008, 128, 224311; F. Santoro, V. Barone, Int. J. Quantum. Chem. 2010, 110, 476-486; F. Santoro, "FCclasses, a Fortran 77 code", http://village.ipcf.cnr.it [2] C.A. Guido, B. Mennucci, D. Jacquemine, C. Adamo, Phys. Chem. Chem. Phys. 2010, 12, 8016 – 8023. [3] M. Lax, J. Chem. Phys. 1952, 20, 1752–1760. [4] E.J. Heller, Acc. Chem. Res. 1981, 14, 368–375. [5] T. Petrenko, F. Neese, J. Chem. Phys. 2007, 127, 164319. [6] M.K. Kretov, I.M. Iskandarova, B.V. Potapkin, A.V. Scherbinin, A.M. Srivastava, N.F. Stepanov, J. Lumin. 2012, 132, 2143–2150.