Coordination studies of some new azopyrazolones ligands with Zr(IV), La(III), Y(III), and U022+

Chelates of pyridine azopyrazolin-5-one derivatives with Zr(IV), La(III), Y(III) and UO22+ have been prepared and characterized on the basis of microanalysis, electronic, IR, 1H NMR spectra. The thermogravimetric analysis confirms the presence of coordinated water molecules. The 1:1 and 1:2 (Mn+:L) ratios are suggested on the basis of spectrophotometric and conductometric data. It is concluded that the ligand L1 and L3 can act, as neutral bidentate ligands while L2 acts as monobasic bidentate. All complexes are thermally stable up to ∼ 2000C