Synthesis and characterization of peroxo complexes of uranium(VI) with some Mannich base ligands

Uranium(VI) peroxo complexes of composition (UO(O2)L-L(NO3)2), where L-L are the Mannich base ligands morpholinobenzyl urea, piperidinobenzyl urea, morpholinobenzyl thiourea, piperidinobenzyl thiourea, mor- pholinomethyl thiourea, piperidinomethyl thiourea, or morpholinomethyl urea, are reported. The synthesized complexes were characterized by use of a variety of physi- cochemical techniques, viz. elemental analysis, molar conductivity, magnetic susceptibility measurements, IR, electronic, mass, 1 H NMR, and 13 C NMR spectroscopy, and TGA/DTA studies. These studies revealed that the com- plexes are both non-electrolytic and diamagnetic in nature. The ligands are bound to the metal in a bidentate mode through carbonyl oxygen or thiocarbonyl sulfur and the ring nitrogen. Mass spectra confirm the molecular mass of the complexes. The antifungal activity of the complexes is greater than that of the corresponding free ligands.