title: Simple and accurate computations of solvatochromic shifts in pi --> pi* transitions of aromatic chromophores.
abstract: A new approach is introduced for calculating the spectral shifts of the most bathochromic pi --> pi* transition of an aromatic chromophore in apolar environments. As an example, perylene in solid and liquid n-alkane matrixes was chosen, and all shifts were calculated relative to one well-defined solid-inclusion system. It was shown that a simple two-level treatment of the solute using Hückel theory yields spectral shifts in excellent agreement with experimental results for the most prominent inclusion sites of perylene in solid n-alkane surroundings and for the dilute solutions in liquid n-alkanes. The idea is general enough to be applied to any aromatic chromophore in a nonpolar solvent matrix. In contrast to earlier treatments, this approach is based on geometry- and environment-dependent polarizabilities, employs an r(-4) dependence for the dispersion energy, and is conceptually very simple and computationally very efficient.
authors.affiliation: Department of Materials, Institute of Polymers, ETH, CH-8092 Zürich, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Heinz
authors.forename: U W
authors.initials: UW
authors.lastname: Suter
authors.forename: E
authors.initials: E
authors.lastname: Leontidis