Transition metal complexes with thiosemicarbazide-based ligands. Part LVI: Nickel(II) complex with 1,3-diphenylpyrazole-4-carboxaldehyde thiosemicarbazone and unusually deformed coordination geometry

Synthesis of a new nickel(II) complex, [Ni(Ph2PzTSC-H)2] with 1,3-diphenylpyrazole-4-carboxaldehyde thiosemicarbazone (Ph2PzTSC), is described. The compounds have been characterized by elemental and thermal analysis, molar conductivity and spectral (UV–Vis, IR, 1H NMR, and 13C NMR) measurements. In the case of complex the magnetic measurement has been also performed. Crystal and molecular structures of both the free ligand and the complex have been determined by single crystal X-ray analysis. It was found that the ligand coordinates in a bidentate NS fashion, in its deprotonated thioenolato form. The cis-square-planar geometry of the complex is significantly distorted tetrahedrally. The Cambridge Structural Database (CSD) study has been performed to obtain geometrical and structural informations on similar nickel(II) complexes in order to compare structural data.

Graphical abstractThe synthesis, crystal, and molecular structure of 1,3-diphenylpyrazole-4-carboxaldehyde thiosemicarbazone (Ph2PzTSC) ligand and its markedly distorted diamagnetic cis-square-planar nickel(II) complex, [Ni(Ph2PzTSC-H)2] is described. The ligand has NS coordination in its thioenolato form.Figure optionsDownload full-size imageDownload as PowerPoint slide