Band-width of charge transfer band of ion-pairs and dipolar molecules in neat and mixed binary solvents

Abstract

Band-width parameters for the charge transfer (CT) band of N-ethyl-4-cyanopyridinium iodide and betaine-dye [2,6-di-phenyl-4(2,4,6-triphenyl-1-pyridino)phenolate] have been measured in various neat and mixed binary solvents. It has been shown that the parameter depends largely on solvation interaction. A suitable analysis of t he parameter in neat solvents provides information regarding various modes of solute-solvent interaction in determining solvent reorganisation. Data in mixed binary solvents point to a deviation from ideal solvation behaviour. The results have been explained in terms of solute-solvent and solvent-solvent interaction. Some data indicating the effect of temperature on these parameters have also been recorded.