Vol. 10, Issue 6 (2022)
Synthesis characterisation and stability constants of lanthanide (III) ion complexes of schiff base and their chemical speciation
Author(s): Dr. Tekale AS
Abstract: The proton-ligand and metal ligand stability constant of 2,4 Diamino thiazole with R-substituted salicylaldehyde (R-5-SH3 and 5-Cl) or 2-hydroxy-1-Nathanldyde ie, (5 mS)2 DCT, (5 CS)2 DCT and (HN)2DCT and lanthanide (III) ion complexes have been determined in ethanol-water (v/v) medium at different ionic strength (µ)=0.2,0.15,0.1 and 0.05 m NaClO4 and different temperatures 35 °C and 45 °C. The effect of dielectric constant on stability has also been studied at different percentages of solvent and variation in different solvent system.
The stability constants of the complexes are found to decrease with increasing ionic strength which is in agreement with Debye-Huckel equation. The stability of complexes containing an O-H or O-M link increases with increasing organic content of the solvent due to decrease in dielectric constant of the bulk solvent.
The thermodynamic parameters (ΔG, ΔH and ΔS) were calculated and over all free energy, enthalpy and entropy changes at room temperature. The negative free energy change (G) in each case indicates that the complexation is spontaneous. The enthalpy changes are exothermic. The positive values for S indicates the complexation reaction are entropically favored under the experimental condition.
Pages: 136-139 | 238 Views 68 Downloads
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How to cite this article:
Dr. Tekale AS. Synthesis characterisation and stability constants of lanthanide (III) ion complexes of schiff base and their chemical speciation. Int J Chem Stud 2022;10(6):136-139.
