Synthesis of Metal Complexes of l-Phenyl-3-methyl-4-benzoylpyrazole-5-one Semicarbazone by Solid-State and Solution Reactions

摘要

l-Phenyl-3-metliyl-4-benzoylpyrazole-5-one semicarbazone (HL) and its complexes have been prepared and characterized on the basis of elemental analyses, IR spectra, ~1H NMR spectra, mass spectra, molar conductivity, thermal analyses and X-ray powder diffraction. The spectral data show that the complexes obtained by solution reactions have the general formulas [ML_2] centre dot n H_2O [M = Mn(II), Co(II), Ni(II), Zn(II)] in which the ligand chelates to the metal ion in a mononegative O,N,O-tridentate fashion. On the other hand, the complexes obtained by solid-state reactions have the formulas [M(HL)(OAc)_2] centre dot n H_2O, in which the ligand acts as a neutral bidenate entity that coordinates through the carbonyl oxygen of the pyrazolone ring, the azomethine nitrogen and the two acetate groups that are monodenate.