Effects of Halogen Bonding in Chemical Activity of Lead(II) Electron Pair: Sonochemical Synthesis, Structural Studies, and Thermal Analysis of Novel Lead(II) Nano Coordination Polymer

The nanoflower lead(II) coordination compound {[Pb(phen)(mu-CH3COO)][PF6]}(n) (1) (phen = 1,10-phenanthroline) was synthesized by a sonochemical method. The nanostructure was characterized by using scanning electron microscopy (SEM), X-ray powder diffraction, elemental analysis, and thermal analysis. The single-crystal X-ray structure shows that the overall structure of 1 is a 1D coordination polymer. Complex 1 has a bridging acetate pathway. Three halogen bonds observed in the structure and the strong halogen bonding of F-Pb causes chemical activity of the lead electron pair. This is further extended into a 3D supramolecular structure by weak mu-mu intermolecular interactions. The coordination number of the lead(II) ions is six, resulting in PbN2O4. PbO nanoparticles were obtained by the thermolysis of 1 at 180 degrees C with oleic acid as a surfactant. The morphology and size of the prepared PbO nanoparticles were further observed using scanning electron (SEM) and transmission electron microscopy (TEM), and were analyzed by X-ray photoelectron spectroscopy (XPS).