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

Potentiometric and Thermodynamic Studies of 2-Thioxothiazolidin-4-one and its Metal Complexes

M. F. El.-Sherbiny

Basic Engineering Science Department, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt

E-mail: sherbinymf@yahoo.com

Received: 25 September 2004

Abstract: Proton—ligand dissociation constants of 2-thioxothiazolidin-4-one and metal—ligand stability constants of its complexes with some metal ions have been determined potentiometrically in 0.1 M-KCl and ethanol—water (volume ratio = 2 : 3). The order of the stability constants of the formed complexes increases in the sequence Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Cd²⁺, La³⁺, Hf³⁺, and Zr⁴⁺. The effect of temperature was studied and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) were derived and discussed. The dissociation process is nonspontaneous, endothermic, and entropically unfavourable. The formation of the metal complexes has been found to be spontaneous, endothermic, and entropically favourable.

Full paper in Portable Document Format: 595a332.pdf

Chemical Papers 59 (5) 332–335 (2005)