5-Methyl-2-hydroxy-acetophenone-thiosemicarbazone and its nickel(II) complex: Crystallographic, spectroscopic (IR, NMR and UV) and DFT studies

A new 5-methyl-2-hydroxy-acetophenone-thiosemicarbazone ligand (L) and its nickel(II) complex [Ni(L)(PPh3)] were synthesized. The crystal structure of free ligand and its complex has been determined by single crystal X-ray diffraction technique. In the complex, thiosemicarbazone ligand is coordinated to nickel through ONS mode. The structures were also characterized by elemental analysis, IR, 1H NMR and UV–Vis. spectroscopies. In addition, the molecular geometries, vibrational frequencies and gauge-independent atomic orbital (GIAO) 1H NMR chemical shift values of the compounds in the ground state have been calculated using the density functional theory (B3LYP) method with 6-311G(d,p) basis set for C, H, N, O, P, S atoms and LANL2DZ basis set for Ni atom. Electronic transitions were calculated using the time-dependent density functional theory (TD-DFT) formalism and the experimental spectra of the compounds have been discussed.

Graphical abstractA new thiosemicarbazone ligand and its nickel(II) complex have been synthesized and characterized by means of elemental analysis, IR, UV and 1H NMR spectroscopies. The spectra of the complex were compared with these of the ligand in order to find out the points of attachment of the ligand to the metal ion in the complex. The crystal structures of the compounds have been determined by single crystal X-ray diffraction technique and were simulated using the DFT method.Figure optionsDownload full-size imageDownload as PowerPoint slide