Ultrasonic-assisted synthesis, characterizing the structure and DFT calculation of a new Pb(II)-chloride metal-ligand coordination polymer as a precursor for preparation of α-PbO nanoparticles

The nanorods of a new Pb(II)-chloride metal-organic coordination polymer, [Pb2Cl2Q2]n(1)(HQ= 8-hydroxyquinoline) was synthesized using the sonochemical synthesis. The characteristics of the compound were determined via the elemental analysis, single-crystal X-ray analysis, scanning electron microscopy (SEM), IR spectroscopy, and powder X-ray diffraction (PXRD). The X-ray structure indicated that the compound included a 2-dimensional polymer in the solid-state with two different centers of Pb(II). Two coordination numbers (6 and 7) with two coordination spheres (symmetrical and unsymmetrical) were observed for the lead (II) centers. The structure showed a self-assembly capability with several weak interactions, such as H-bonds and π–π interactions. Sonochemical results showed the uniform, rod-like morphology of the title compound. The computational DFT results demonstrated that the HOMO (highest occupied molecular orbital) was confined primarily between one Cl– anion and Pb centers, whereas the LUMO (lowest unoccupied molecular orbital) was roughly delocalized on the Q− ligand N and O atoms comprising the other Cl– anions. The estimated gap of HOMO–LUMO was 3.708 eV and the composite was highly shock-sensitive. The α-PbO nanostructures were produced by thermolysis of 1 at 180 °C via oleic acid as a surfactant.