Cobalt(II) and Copper(II) Complexes with New Ditopic Ligand 5-(2-(1H-Tetrazol-1-yl)phenyl)-1H-tetrazole: Synthesis and Properties

A procedure for the synthesis of the new ditopic ligand combining in the structure 1- and 5-substituted tetrazolyl cycles, 5-(2-(1 H -tetrazol-1-yl)phenyl)-1 H -tetrazole (HL), is developed. The coordination compounds of Co(II) and Cu(II) halides [Co(HL) 2 Cl 2 ], [Cu(HL) 2 Cl 2 ], [Cu(HL) 2 Br 2 ], and [CuL 2 (H 2 O)] n based on ligand HL are synthesized. The complexes are studied by elemental analysis, diffuse reflectance spectroscopy, IR spectroscopy, X-ray diffraction (XRD), and static magnetic susceptibility. The crystal structure of the molecular coordination polymer [CuL 2 (H 2 O)] n is determined by XRD (CIF file CCDC no. 2127210). The temperature and field dependences of the magnetization show that the magnetic properties of the synthesized Cu(II) complexes are due to exchange interactions in one-dimensional chains of the copper ions ( S = 1/2). For complex [Cu(HL) 2 Br 2 ], the parameters are shifted toward the enhancement of the antiferromagnetic interaction compared to the analog containing the chloride ion.