Ligational Behaviour of a New Pyrazole Derived Thiosemicarbazone, a Potential Antiviral Agent: Cobalt(III), Nickel(II) and Copper(II) Complexes of Neutral and Deprotonated 5(3)-Methylpyrazole-3(5)-aldehydo-4-phenylthiosemicarbazone

TLDR: In this paper, the coordinating behavior of the thiosemi-carbazone has been investigated by isolation and characterization of its complexes with Co(III), Ni(II), and Cu(II) having different counterions, Magnetic and spectral data indicate Co(MPzAP) 2X (X = counter ion) as spin paired octahedral species with the ligand in the deprotonated thiol form.

Abstract: The title compound (abbreviated as IIPzAPH) has been synthesised and physico-chemically (IR, PMR, mass spectra) characterized for the first time. The coordinating behaviour of the thiosemi-carbazone has been investigated by isolation and characterization of its complexes with Co(III), Ni(II) and Cu(II) having different counterions, Magnetic and spectral data indicate Co(MPzAP) 2X (X = counter ion) as spin paired octahedral species with the ligand in the deprotonated thiol form, while Ni(MPzAPH) 2X2 and Cu(MPzAPH) X2 are proposed to be spin-free octahedral with the ligand in the neutral thione form. A spin-paired diamagnetic Ni(MPzAP) (SCN) has also been identified. IR data point out that the pyrazolyl ring nitrogen (tertiary), the azomethine nitrogen and the sulphur atom are the points of attachment with the metal ion in all these complex species.