Thiocyanate precursor impact on the formation of cobalt complexes: Synthesis and characterization

Two new thiocyanate complexes have been synthesized with two different thiocyanate anion sources using 1-(2-Pyrimidyl) piperazine andCoCl2.6H2O. These compounds were characterized by single X-ray diffraction, FTIR, UV-Visible and TGA-DTA. The antibacterial activity was also examined. The XRD showed that compounds 1 and 2 crystallized into monoclinic and orthorhombic systems respectively. In compound 1, cobalt is surrounded by two isothiocyanate anions and two nitrogen-amides, while in compound 2 it is surrounded by four isothiocyanate ligands and a separate protonated amide. Different interactions packed the system through N-H···S, N-H···O and O-H ···S hydrogen bonds forming a ring. Gap energy determination revealed two diverse behaviors, the first being characteristic of a semiconductor and the second of an insulator. In the 10-500 °C range, the thermal behaviors were investigated and showed the decomposition of the two complexes with metal complexes residues. The antibacterial analysis presented a weak performance.