Solvatochromism in binary solvent mixtures. Response models to the chemical properties of reference probes

The present work analyzes the solvent effects on the electronic absorption spectra for a set of solvatochromic solutes in several binary mixtures of a polar aprotic hydrogen-bond acceptor solvent with a cosolvent with potential hydrogen-bond donor capability, in terms of preferential solvation models. It compares the response models of the explored mixtures with respect to the chemical properties of the reference probes. It relates the results obtained with the solvatochromic solutes to the solvent effects on an aromatic nucleophilic substitution reaction. It also gives an evaluation of the degree of convergence for the values of a solvent property determined by individual probes, in order to analyze the validity of the solvatochromic indicators for the characterization of mixed solvents.