Spectral studies of some azodyes in different solvents

ABSTRACT

The spectral behaviour of some azadyes was investigated in different organic solvents of varying polarities at room temperature. The ionization constants of studied dyes were determined in aqueous buffer solutions and in different organic solvents as well as in ethanol-water mixtures. The spectra in the mixed solvent proved the formation of molecular complexes between the solute and ethanol, for which the stability constant and heat of formation are determined. The variation of absorbance with pH is utilized for the determination of pK a