Coordination Polymer of M(II)-Pyrazinamide (M = Co, Cd) with Double End-to-End Thiocyanate Bridge

International Conference on Chemistry and Material Science 2017

化学;材料科学

Prananto, Yuniar Ponco^1

Department of Chemistry, Faculty of Mathematics and Natural Sciences, Brawijaya University, Jl. Veteran 01, Malang

65145, Indonesia^1

关键词: Anti-bacterial activity;    Coordination Polymers;    Coordination sites;    Crystal packings;    Layering techniques;    Melting point determination;    Polymeric structures;    Single crystal XRD;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/299/1/012032/pdf
DOI  :  10.1088/1757-899X/299/1/012032

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Pyrazinamide (pza, C4N2H3-CONH2) is a good ligand for coordination polymer. Their transition metal complexes are known to have antibacterial activities, magnetic properties, etc. Coordination polymers of M(II)-pyrazinamide with thiocyanate (M = Co (a), Cd (b)), prepared using bench-top layering technique with M(II):pza:SCN ratio of 1:2:2, is successfully crystallised at room temperature. Single crystal XRD was used to determine the crystal structure. Infrared and melting point determination were also performed. Crystal structure of both complexes, solved in Triclinic P-1, show that each octahedral metal centre is connected to two adjacent metal centres by double end-to-end thiocyanate bridge forming a 1D polymeric structure with M•••M distances of 5.524 Å (in a) and 5.887 Å (in b). Two monodentate pyrazinamide ligands occupy the rest of the coordination sites on the metal centre in a trans relationship. Only in complex a, one lattice pyrazinamide molecule is involved in the asymmetric unit. Crystal packing of both a and b are also displaying non-covalent networks as a result of hydrogen-bonding involving the pyrazine ring, amide and carbonyl groups between adjacent chains and π•••π interactions (only occurred in a). In addition, the observed melting points of both a and b are relatively close to each other (around 180°C), and ATR-IR spectra support the presence of the bridging thiocyanate and terminal pyrazinamide.