STABILITY CONSTANTS AND THERMODYNAMICS OF COMPLEXATION OF SCHIFF BASE HYDRAZONES DERIVED FROM 3-HYDRAZINO-6-:PHENYL PYRIDAZINE AND ACETOPHENONE DERIVATIVES WITH UO2+, TH4+, PR3+ AND YB3+ IONS

Authors : H S SELEEM

Pages : 0-0

Doi:10.1501/Commub_0000000364

View : 26 | Download : 8

Publication Date : 2002-01-01

Article Type : Research Paper

Abstract :The stepwise stability constants of UO22+, Th4*, Pr3+ and Yb3* ions with 3insert ignore into journalissuearticles values(acetophenonehydrazone);-6-phenyl pyridazine insert ignore into journalissuearticles values(AHP);, 3-insert ignore into journalissuearticles values(p-chloroacetopheon- hydrazone);-6-phenyl pyridazine insert ignore into journalissuearticles values(C1AHP); and 3-p-aminoacetophenonehydrazone);-6- phenyl pyridazine insert ignore into journalissuearticles values(NH2AHP); have been investigated potentiometrically in 75% insert ignore into journalissuearticles values(v/v); dioxane-water and 0.1 MKNO3 at different temperatures insert ignore into journalissuearticles values(298,308 and 318K);. For the same ligand, the order of stability decreases in the sequence; Th4* > UOf > Yb3* > P/*. The thermodynamic functions insert ignore into journalissuearticles values(21insert ignore into journalissuearticles values(7, AH and zlS); for the dissociation and the complexation reactions have been evaluated and discussed. The higher negative values of AH suggest an octahedral environment around the metal ions in solution. Also, the effect of the dielectric constant of the solvents, mole fraction and ionic strength of the medium on the stability of UO22+-complexes were discussed.
Keywords : THERMODYNAMICS, COMPLEXATION, HYDRAZONES

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