Studies on Solution Properties of Some Amino Acids in Aqueous Mixture of Catechol

Abstract

Apparent molar volumes, V _φ, viscosities, η, and apparent isentropic compressibilities, K _φ, of glycine, L-alanine, L-valine and L-leucine in 0.05, 0.10, 0.15 mol Kg⁻¹ catechol solutions have been determined at 298.15 K by measuring the densities, viscosities and ultrasonic speed of the above solutions respectively. The standard partial molar volumes, , standard volumes of transfer, , standard partial isentropic compressibilities, , transfer compressibilities, , hydration number, N _w , of the amino acids have been calculated for investigating the various interactions in the ternary solutions. The linear correlation of partial molar volume and viscosity B-coefficients with increasing number of carbon atoms in the alkyl chain have been used to explain the contribution of charged end group (, COO⁻) and the ‒CH₂ group to . The results have been interpreted in the light of solute-solvent interactions in the mixed ternary solutions.

Keywords:

• Amino acids
• apparent molar volumes
• catechol
• hydration number
• isentropic compressibilities
• viscosity B-coefficients

Acknowledgments

The authors are grateful to the Departmental Special Assistance Scheme under the University Grants Commission, New Delhi (No. 540/6/DRS/2002, SAP-1) for financial support. One of the authors is also grateful to UGC Research Fellowship in science Ref. UGC letter No. F. 4-1/2006 (X1 plan/BSR) for sanctioning a Junior Research Fellowship and providing financial aid in support of this research work.