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

• Published in: Polyhedron 2019-03, Vol.161, p.222-230
• Main Authors: Hannachi, Anissa, Valkonen, Arto, Rzaigui, Mohamed, Smirani, Wajda
• Format: Article
• Language: English
• Subjects: Crystal structures; Metal complexes; physico-chemical study; Thiocyanate precursor
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2018.12.039

Two different metal complexes structures have been obtained using two different thiocyanate precursors. [Display omitted] Two new thiocyanate complexes have been synthesized with two different thiocyanate anion sources using 1-(2-pyrimidyl)piperazine and CoCl2·H2O. These compounds were characterized by single X-ray diffraction, FTIR, UV–Vis 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 NH⋯S, NH⋯O and OH⋯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.