Synthesis of Metal Complexes of 1‐Phenyl‐3‐methyl‐4‐benzoylpyrazole‐5‐one Semicarbazone by Solid‐State and Solution Reactions

1‐Phenyl‐3‐methyl‐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 [ML₂] · nH₂O [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] · nH₂O, 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.

The authors are grateful to the National Natural Sciences Foundation of China (No. 20262005) for financial support.

Keywords:

• complex
• pyrazolone
• semicarbazone
• solid–state reaction

Notes

The authors are grateful to the National Natural Sciences Foundation of China (No. 20262005) for financial support.