COMPLEXATION OF URANYL -HYDROXY-3-METHYL-1-PHENYLPYRAZOL-4-YL)METHANES()) AND THORIUM (TH4+) WITH ARYLBIS(5)

The thermodynamic parameters of complexes of UO2(II) and Th(IV) cation s with s(5-hydroxy-3-methyl-1-phenylpyrazol-4-yl)methanes and other de rivatives have been measured in 75% (v/v) methanol-water and 0.10 M KN O3 using potentiometry. Comparison of the experimental and calculated (using the modified Born equation) values of DELTAG indicates the inne r sphere nature of all the complex systems. The solid complexes were i solated and characterized by elemental analysis, conductance, infrared spectra, and by TG, DTG and DTA measurements. The ligands behave towa rds the metal ion as monobasic bidentate ligands.