SOLVENT EFFECTS ON LINEAR AND NONLINEAR-OPTICAL PROPERTIES OF DONOR-ACCEPTOR POLYENES - INVESTIGATION OF ELECTRONIC AND VIBRATIONAL COMPONENTS IN TERMS OF STRUCTURE AND CHARGE-DISTRIBUTION CHANGES

Citation
R. Cammi et al., SOLVENT EFFECTS ON LINEAR AND NONLINEAR-OPTICAL PROPERTIES OF DONOR-ACCEPTOR POLYENES - INVESTIGATION OF ELECTRONIC AND VIBRATIONAL COMPONENTS IN TERMS OF STRUCTURE AND CHARGE-DISTRIBUTION CHANGES, Journal of the American Chemical Society, 120(34), 1998, pp. 8834-8847
Citations number
53
Categorie Soggetti
Chemistry
ISSN journal
00027863
Volume
120
Issue
34
Year of publication
1998
Pages
8834 - 8847
Database
ISI
SICI code
0002-7863(1998)120:34<8834:SEOLAN>2.0.ZU;2-0
Abstract
We investigate the influence of solvation media upon the relationship among structure, spatial distribution of electron density, and linear and nonlinear electric properties for two series of push-pull pi-conju gated molecules. The analysis is performed on both electronic and vibr ational components of static polarizability and first hyperpolarizabil ity, and the effects solvent induce on them are analyzed singularly wi thin the framework of the polarization continuum model. Solvent is fou nd to affect the extent of charge separation induced in the ground sta te of these molecules. This charge separation leads to a geometric dis tortion, measured by the bond-length-alternation (BLA) parameter, whic h shows a solvent-induced evolution of the molecular geometry from a n eutral, bond-alternated polyene-like structure, to a partially ionic c yanine-like structure, and ultimately to an ionic bond-alternated stru cture. As a consequence large changes in the linear and nonlinear resp onse properties are found, in both their electronic and vibrational co ntributions. Regarding the latter, we recall that studies on vibration al (hyper)polarizabilities for molecular systems in solution are prese nted here for the first time.