Intermolecular interactions in binary and ternary solutions of two cycloimmonium-carboethoxy-anilido-methylids

Two cycloimmonium ylids with pyridinium and iso-quinolinium as heterocycle and having common carbanion were studied from the point of view of the solvent influence on electronic absorption spectra in binary and ternary solutions. The supplies of the universal and specific interactions to the spectral shifts in the electronic absorption spectra of hydroxyl solutions were separated. The strength of the specific interactions of the ylid molecules with octanol was estimated by using ternary solutions in binary solvent Octanol + Dichloroethane, in which the universal interactions have similar strengths. Quantum mechanical calculations and also the solvatochromic effect allowed us estimating the values of the molecular dipole moments in the excited state of the studied ylids. The conclusions showed that by excitation the molecular dipole moment of the studied ylids decreases or changes its sense, due to the electronic charge transport from the carbanion towards the heterocycle. (C) 2013 Elsevier B.V. All rights reserved.