Direct Synthesis of PbO Nanoparticles from a Lead(II) Nanoflower Coordination Polymer Precursor: Synthesis, Crystal Structure and DFT Calculations of [Pb(pcih)N3H2O] n with the Terminal Azide Unit

Abstract

The first nanoflower lead(II) coordination compound, [Pb(pcih)N3MeOH] n (1), (“pcih” is the abbreviations of 2-pyridinecarbaldehyde isonicotinoylhy-drazoneate) were synthesized by a sonochemical method. The new nano-structure was characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, elemental analyses and IR spectroscopy. Single crystalline material was obtained using a heat gradient applied to a solution of the reagents. Compound 1 was structurally characterized by single crystal X-ray diffraction. The determination of the structure by single crystal X-ray crystallography showed that the complex taking the form of a zig-zag one dimensional polymer in the solid state and the coordination number of PbII ions is six, (PbN4O2), with three N-donor and one O-donor atoms from two “pcih” and one O-donors from methanol and one N atom from terminal azide anion. It has an asymmetrical coordination sphere. The supramolecular features in these complexes are guided and controlled by weak directional intermolecular interactions. The chains interact with each other through π–π stacking interactions creating a 3D framework. After thermolysis of 1 at 180 °C with oleic acid, pure phase nano-sized lead(II) oxide was produced. The morphology and size of the prepared PbO samples were further observed using SEM.