Zinc(II) Complexes with Thiadiazole-1,3,4 Derivatives

Abstract

Zn(II) complexes [ZnL\(_{2}^{n}\)Х₂] and [ZnL\(_{3}^{n}\)(NO₃)₂], where n = 1, 2; X = Cl, Br, I; L¹ is 2-aminothiadiazole-1,3,4, and L² is 2-amino-5-methylthiadiazole-1,3,4, have been synthesized. The resulting complexes have been studied using elemental analysis, IR and ¹H NMR spectroscopies. The structure of complex [ZnL\(_{2}^{2}\)Br₂] has been determined by X-ray diffraction (CIF file CCDC no. 2251742). It has been found that the ligand molecules of 2-amino-5-R-thiadiazoles-1,3,4 (R = –H, –CH₃) are coordinated monodentately by the endocyclic nitrogen atom located in the α-position to the amino group. The polyhedron of the central atom of halide complexes is a slightly distorted tetrahedron, the coordination sphere of which is formed by two halide atoms and two endocyclic nitrogen atoms. According to the spectral data, during complexation in a solution of complex [ZnL\(_{2}^{2}\)Br₂], coordinated ligands L² undergo amino-imine tautomerism to form a heterocyclic amine with a nitrogen atom in the heterocycle. The polyhedron of the central atom for nitrate complexes is a slightly distorted trigonal bipyramid, in the coordination sphere of which three nitrogen atoms of the ligands are located in the equatorial plane and two oxygen atoms of two nitrate anions are located in the axial position.