Theoretical modeling of UV-Vis absorption and emission spectra in liquid state systems including vibrational and conformational effects: the vertical transition approximation

摘要

In this paper we describe in detail a general and efficient methodology, based on the perturbed matrixudmethod and molecular dynamics simulations, to model UV-Vis absorption and emission spectraudincluding vibrational and conformational effects. The basic approximation used is to consider all theudchromophore atomic coordinates as semiclassical degrees of freedom, hence allowing the calculationudof the complete spectral signal by using the electronic vertical transitions as obtained at eachudpossible chromophore configuration, thus including the contributions of vibrations and conformationaludtransitions into the spectrum. As shown for the model system utilized in this paper, solvatedud1-phenyl-naphthalene, such an approximation can be rather accurate to reproduce the absorptionudand emission spectral line shape and properties when, as it often occurs, the vertical vibronic transitionudlargely overlaps the other non-negligible vibronic transitions.