Synthesis, Crystal Structure and Properties of Novel Zinc(II) and Cobalt(II) Chain Complexes with 3,5-dimethylpyrazole and Thiocyanate

This paper presents the synthesis, crystal structure and properties of new zinc(II) and cobalt(II) 1-D chain complexes with 3,5-dimethylpyrazole and thiocyanate, [M(pz*)₂(NCS)₂]·H₂O (M=Zn, Co; pz*=3,5-dimethylpyrazole). The structures of both complexes were determined by X-ray diffraction methods and showed very similar crystallographic character. The M(II) ion in each complex is coordinated to two pyrazole nitrogen atoms and two nitrogen atoms of NCS⁻ to form a distorted tetrahedron. In the cell of each complex are four complex molecules and four H₂O molecules. Adjacent complex molecules are connected by hydrogen bonds to form 1-D chain. Each sulfur atom in the complex is connected by a weak coordination bond with an M(II) ion of an adjacent chain to form a sawtooth-type double 1-D chain structure. The bond distances Zn-S and Co-S are 3.919 Å and 3.853 Å, respectively.