Heteroaromatic Chromophores: Structure, Electric Properties, Condensed Phase and Aggregation Effects: a Combined Experimental and Theoretical Study

We present a combined computational and experimental study on structural and electric properties of recently synthesized heteroaromatic dyes and their simple aggregates. Ab initio and density functional theory calculations are carried out to investigate ground state and excited state properties along with their modulation induced by the solvent described with the implicit solvent polarizable continuum model. The results are compared with experimental data concerning spectroscopic studies. Electronic and vibrational contributions to the first hyperpolarizability and condensed phase effects on these properties are also evaluated for single or selected dimeric chromophore structures. Intermolecular interactions are evaluated both at correlated ab initio level and with simplified atomistic models employing molecular mechanics force fields parametrized, as regard electrostatic interactions, on the basis of ab initio computed partial atomic charges. Specific chromophore orientations are considered and the results of the two procedures are compared.