ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Potentiometric and Thermodynamic Studies of Azosulfonamide Drugs. X

A. A. El-Bindary, A. Z. El-Sonbati, E. H. El-Mosalamy, and R. M. Ahmed

Department of Chemistry, Faculty of Science (Demiatta), Mansoura University, Demiatta, Egypt

E-mail: abindary@yahoo.com

Received: 18 July 2002

Abstract: Dissociation constants of azosulfonamide derivatives of rhodanine have been determined potentiometrically in 0.1 M-KCl and 30 vol. % ethanol—water mixture. The data are discussed in terms of the electron nature of the substituents and of the change in temperature. The pK₁^H values have been found to increase with increasing electron-donating nature of the substituents. The evaluated thermodynamic parameters (ΔG, ΔH, and ΔS) indicated that the dissociation processes are not spontaneous, they are endothermic and entropically unfavourable.

Full paper in Portable Document Format: 574a255.pdf

Chemical Papers 57 (4) 255–258 (2003)