Spectroscopic and ultrasonic studies on the molecular interaction of certain aromatic amines with p-chloranil

Ultrasonic investigation has been carried out on five binary and four ternary liquid mixtures to identify the dominance of solute–solute interactions. p-Chloranil is used as acceptor and four aromatic amines are used as donors. Primary, secondary and tertiary amines were used mainly to determine the difference in the site of complex formation. The study was made in DMSO at 303 K and at atmospheric pressure. The trend in acoustical and excess thermo acoustical parameters of mixtures containing p-chloranil and amines is used to identify the existence of intermolecular interaction, probably through hydrogen bonded or charge transfer complex formation. The formation of 1:1 complexes between p-chloranil and aromatic amines was established by UV–visible spectroscopic methods at 303 K. The formation constants of the charge transfer complexes were computed by spectroscopic and ultrasonic methods which show similar trends and well establish the influence of structural aspect of the amine (donor) on the stability of charge transfer complexes.