An Ab initio simulation of the UV/visible spectra of N-benzylideneaniline dyes

Abstract

The structural parameters and the absorption spectra of more than thirty N-benzylideneaniline dyes have been determined with a theoretical scheme combining the time-dependent density functional theory and the polarizable continuum model. For the unsubstituted molecule, the PBE0 hybrid nicely reproduces both the measured structural parameters and the absorption spectrum, and we demonstrate that the nature of the two first transitions is reversed compared with azobenzene. For the set of substituted compounds, the average TD-DFT error (0.19 eV), that can be significantly reduced by a simple statistical treatment, mainly originates in the charge-transfer states of push-pull derivatives, whereas local transitions are accurately modeled. © 2009 Wiley Periodicals, Inc.