SYNTHESIS, CRYSTAL STRUCTURE OF NICKEL MONONUCLEAR COMPLEX WITH REDUCED THIOSEMICARBAZONE OF GLYOXYLIC ACID (H2TAA)

Abstract

Ni (II) complex with potentially tridentate ligand, 2-[2-(aminothioxomethyl) hydrazinyl]acetic acid (H2TAA), was synthesized. The ligand was obtained via reduction of the corresponding thiosemicarbazone of glyoxylic acid by borohydride. The structure of the synthesized nickel complex coordination compounds has been studied by the methods of IR and electronic absorption spectrometry, elemental analysis, and thermogravimetry. The molecular structure of the complex 1 has been characterized by crystal X-ray diffraction. X-ray diffraction studies have shown that the Ni(C3H6N3O2S)2 (1) complex is mononuclear, in which the coordination around the metal is octahedral coordination geometry of nickel, made up of two sulfur atoms of thiolic, two nitrogen atoms of the azomethine group and two oxygen atoms of carboxylate from two ligands. The asymmetric unit of the complex 1 consists of one Ni(II) ion and one 2-[2-(aminothioxomethyl)hydrazinyl]acetic acid (H2TAA) ligand. The thermal properties of the synthesized complex were investigated by TGA/DTA. TGA and DTA curves of the complex was obtained in the nitrogen atmosphere.The thermogram of 1 complex shows five decomposition steps within the temperature range of 22–990 °C with decomposition steps in the temperature range of 95–990 °C. The magnetic moment (3.04 B.M.) of the Ni(II) complex is indicative of the octahedral geometry. The electronic spectrum of the Ni(II) complex shows three bands at 10.200 cm-1, 11.000 cm-1, 16.475 cm-1.