16623-42-0Relevant articles and documents
THERMODYNAMIC BEHAVIOUR AND STABILITY CONSTANTS OF 5,5-DIMETHYLCYCLOHEXANE-2-(2'-HYDROXYPHENYL)HYDRAZONO-1,3-DIONE COMPLEXES
Ramadan, Atef A. T.,Abdel-Moez, Mohammed S.,El-Maraghy, Salah B.,El-Inany, Gaber A.
, p. 3 - 12 (2007/10/02)
The thermodynamic behaviour and stability constants of DCPHD, DC-4-Cl-PHD and DC-4-Me-PHD and their complexes with lanthanide cations have been determined potentiometrically in 75percent (v/v) isopropanol-water at an ionic strenght of 0.10 M KNO3.The relation between stability constants of complexes and the basicity of the ligands (Σ PKiH) is not linear.The representation of log K1 and log K2 vs.Z2/r, of lanthanide cations gives linear increase from La to Eu, this is followed by subsequent decrease from Gd to Tb, and a gradual increase through the rest of the series.The thermodynamic functions have been calculated for Ni(2+), Nd(3+), and Yb(3+), and show that the stability of the complexes decrease with an increase in temperature and the complex formation process is exothermal.The order of ΔH deg and ΔS deg is: DC-4-Cl-PHD > DCPHD > DC-4-Me-PHD.
