A thermodynamic and spectrophotometric study of the complex formation of copper(II) ions with sulphide-containing α,ω-aminopyridines in aqueous solution
Laboratory for General and Inorganic Chemistry-B, University of Ghent, Krijgslaan 281, B-9000 Ghent Belgium
Abstract:
The complexation in aqueous solution of ligands of the type (CH2)n?1 S(CH2)mNH2 (n and m = 2 or 3) with Cu(II) has been investigated. The thermodynamic functions ΔG, ΔH and ΔS of complex formation have been determined at 25°C in 0.5 M KNO3 solution by means of potentiometric and direct calorimetric titrations. They revealed that the ligands studied act as tridentates towards Cu(II).It was found that the CuL2+ complexes having one or two six-membered chelate rings are more distorted than their analogues with only five-membered chelate rings.The CuL2+2 complex with L = CH2SCH2CH2NH2 was found to be a strong covalent complex, in which both ligand molecules were completely coordinated.
