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

Potentiometric and Thermodynamic Studies of 3-(4-Methoxyphenyl)-5-azorhodanine Derivatives and their Metal Complexes with Some Transition Metals. XIV

A. A. Al-Sarawy, A. A. El-Bindary, A. Z. El-Sonbati, and T. Y. Omar

Department of Mathematical and Physical Sciences, Faculty of Engineering, Mansoura University, Mansoura, Egypt

E-mail: abindary@yahoo.com

Received: 25 February 2004

Abstract: A series of 3-(4-methoxyphenyl)-5-azorhodanine derivatives have been prepared and characterized by elemental analysis, 1 H NMR, and IR spectra. Proton—ligand dissociation constants of the derivatives and metal—ligand stability constants of their complexes with Mn 2+ , Co 2+ , Ni 2+ , and Cu 2+ ions have been determined potentiometrically in 0.1 M-KCl and 40 vol. % ethanol—water mixture. The influence of substituents on the dissociation and stability constants was examined on the basis of the electron-repelling property of the substituent. The stability constants of the formed complexes increase in the order Mn 2+ , Co 2+ , Ni 2+ , Cu 2+ . The effect of temperature was studied and the corresponding thermodynamic parameters (Δ G , Δ H , and Δ S ) were derived and discussed.

Full paper in Portable Document Format: 594a261.pdf

Chemical Papers 59 (4) 261–266 (2005)