Environment effect on the electronic absorption spectra of crystal violet

The optical characterization and the influence of solvent-solvent interaction on the visible spectra of crystal violet were investigated. The spectroscopic measurements of the solvation of the dye in a polar nematic matrix and some isotropic solvents, mainly alcoholic systems, were correlated with the solvent properties as represented by their dielectric constants, ε, and dipole correlation factors, g. The interaction of the ionic dye with the anisotropic surrounding and with that of the isotropic solvents was investigated and compared. The solvent-solvent interactions can strongly influence the shape and intensity of absorption bands as well as solvent-solute and solute-solute interactions (i.e. dye aggregation, ion pair formation). Dichroic ratios R and degree of anisotropy S of this ionic dye in the liquid crystalline host were investigated by measuring the intensity of the absorption bands in the visible region of parallel aligned samples.