title: Three-dimensional reference interaction site model self-consistent field analysis of solvent and substituent effects on the absorption spectra of Brooker's merocyanine.
abstract: Solvent and substituent effects on the absorption spectra of Brooker's merocyanine (BM) are investigated using the three-dimensional reference interaction site model self-consistent field method and time-dependent density functional theory. The π-π* excitation energies are computed for BM and its derivative 2,6-di-tert-butyl (di-t-Bu) BM. The behaviors of the computed excitation energies with increasing solvent polarity are in good agreement with those of the corresponding experimental measurements. In addition, analysis of the solute-solvent interaction energies and spatial distribution functions reveals that the effects of the solvent on the absorption spectra are reduced by the steric hindrance of the t-Bu groups. Furthermore, from the difference in the solute-solvent interaction energies of BM and di-t-Bu BM, it is shown that the effect of the t-Bu substituents on the absorption spectrum is greater in high-polarity solvents.
authors.affiliation: Department of Chemistry, Graduate School of Sciences, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Chemistry, Graduate School of Sciences, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Yoshida
authors.affiliation: Department of Chemistry, Graduate School of Sciences, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Nakano
keywords: 3D-RISM-SCF method; Brooker's merocyanine; solvatochromism; solvent effect; substituent effect