Supramolecular structure of Cu(II) and Zn(II) complexes based on 2,2′:6′,2"-terpyridine, thermal and biological studies

Two supramolecular metal complexes [Cu(II)(terpy)(PCP)(NO3)](1) and [Zn(II)(terpy)(NO3)(2)](2) (terpy=2,2':6',2aEuro(3)-terpyridine) (PCP = Pentacyanopropenide) were synthesized and structurally characterized by Single-crystal X-ray diffraction. Single-crystal X-ray diffraction revealed that the PCP ligand coordinated to Cu(II) ion through one CN group, and it was absent from the coordination sphere of Zn(II) complex. In complexes (1) and (2), 1D chain was formed through C1-H1 center dot center dot center dot O1 and C4-H4 center dot center dot center dot O2 hydrogen-bonding interactions, respectively. The crystal structure was further stabilized by pi-pi stacking interactions. The thermal stabilities of these compounds were investigated. Furthermore, antimicrobial activities of these compounds were investigated against eight types of bacteria. The copper complex exhibited a significant activity against three types of bacteria with minimal inhibitory concentrations (MICs) under one microgram per milliliter.