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

Potentiometric and Conductometric Studies on the Complexes of Some Transition Metals with Rhodanine Azosulfonamide Derivatives. XI

A. T. Mubarak, A. Z. El-Sonbati, and A. A. El-Bindary

Department of Chemistry, Faculty of Science, King Khalid University, P.O.Box 9004, Abha 61413, Saudi Arabia

E-mail: ahmadtahir20@hotmail.com

Received: 29 September 2003

Abstract: Stability constants of bivalent (Mn²⁺, Co²⁺, Ni²⁺, and Cu²⁺) metal ion complexes with rhodanine azosulfonamide derivatives have been determined potentiometrically in 0.1 M-KCl and 30 vol. % ethanol—water mixture. The stability constants of the formed complexes increase in the order Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺. The influence of substituents on the stability of the complexes was examined on the basis of electron repelling property of the substituent. The effect of temperature on the stability of the complexes formed was studied and the corresponding thermodynamic quantities (ΔG, ΔH, and ΔS) were derived and discussed. The stoichiometries of these complexes were determined conductometrically and indicated the formation of 1:1 and 1:2 (n(metal):n(ligand)) complexes.

Full paper in Portable Document Format: 585a320.pdf

Chemical Papers 58 (5) 320–323 (2004)