Spectroscopic, crystal structure and thermal studies of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) with 5-amino-4-arylazo-3-methyl-1-phenylpyrazole (aryl=C₆H₅,o-C₆H₄COOH,o-C₆H₄OH)

Abstract

5-Amino-4-arylazo-3-methyl-1-phenylpyrazole (aryl = C₆H₅,o-C₆H₄COOH,o-C₆H₄OH) and its complexes with Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) ions were synthesized. The complexes are in the ratio 1 : 1 and 1 : 2 (metal : ligand). Ligands and complexes were subjected to elemental analysis, IR, Raman, UV-Vis and ¹H-NMR spectroscopy. The mass spectra of the ligands were discussed. Thermal analysis and magnetic measurements were carried out for the prepared complexes. The X-ray single crystal structure of [Ni(L1)₂] was performed. The investigated pyrazole compounds coordinate as bidentate ligands through amino and azo nitrogens or tridentate through NNO. The molar conductance of the chelates is measured and reflected the non-electrolytic nature of the prepared complexes.

Keywords:

• Arylazo-pyrazoles
• Azo-complexes
• Spectroscopy
• X-ray
• Thermal
• Magnetic moment

Acknowledgements

The authors are indebted to Professor Dr Y. Abd El-Hammed Badr (Professor of Solid Physics, National Institute of Laser Enhanced Sciences, Cairo University, Giza, Egypt) for Raman measurements. The authors gratefully acknowledge Dr M.A.F. Sharaf (Associate Professor of Organic Chemistry, Chemistry Department, Faculty of Science, Cairo University) for his help, advice and guidance which were given during this dissertation.