Synthesis, Magnetic, Spectral and Biological Studies of Copper(II) Complexes of 4-Benzoyl-3-Methyl-1-Phenyl-2-Pyrazolin-5-One N(4)-Substituted Thiosemicarbazones

The synthesis and characterization of copper(II) complexes with 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one thiosemicarbazone and N(4)-substituted thiosemicarbazones are reported. Elemental analysis, molar conductivities, magnetic measurements and spectral (i.r., electronic, e.s.r., and n.m.r.) studies have been used to characterize the complexes. The i.r. spectra show that the thiosemicarbazones behave as bidentate ligands, either in the thione or thiolato form. Stereochemistries are proposed for the complexes on the basis of spectral and magnetic studies. Both the thiosemicarbazones and their complexes show either modest or no growth inhibitory activity against Aspergillus niger and Paecilomyces variotii.