Solvatochromism of dyes. Part III. Solvatochromism of merocyanines in some binary mixtures of solvents.SA-SAB-SB, a new model of solvatochromism

A quantitative model of solvatochromism in a binary solvent system is presented. Although it is derived for merocyanine and betaine dyes, it explains a majority of known examples of solvatochromism in binary solvents. The model provides an estimation of equilibrium constants between particular types of solvates present therein. UV–VIS absorption spectra of solvated species can be simulated. They perfectly fit the experimental data. The model proposed describes the internal solvent picture from the solute point of view, which differs from other known models and may be useful for studying the structure of liquids © 1997 John Wiley & Sons, Ltd.