Thermal decomposition and biological activity of two supramolecular hybrid nitrates templated by piperazine

The combination between piperazine, nitrate anions and nickel/zinc metals provided two new hybrid compounds with the general formula (C4H12N2)(2)[M-II(H2O)(6)](NO3)(6) [M-II: Ni (1) and Zn (2)]. Their characterization is performed through FTIR spectroscopy and single-crystal X-ray diffraction which gives, as a result, isotype crystal structures, according to the triclinic system (space group PA <<), built from: isolated metallic cations coordinated by six water molecules in a distorted octahedral environment [M-II(H2O)(6)](2+), free nitrate anions and protonated piperazine related together through a hydrogen bond network. These bonds together with other attractive forces, being responsible for the crystal formation, were examined using density-functional theory electron density and the non-covalent interaction plot technique. The thermal behavior of the two materials, studied by thermogravimetric analysis and thermal-dependent X-ray diffraction analysis, starts with the dehydration step proceeding differently according to the used metal. The total decomposition leads to the formation of metal oxides: NiO and ZnO. In order to evaluate their biological activity, the two hybrids have been screened against bacteria and fungi and the findings have been reported and explained. [GRAPHICS] .