Ultrasonic-assisted synthesis of nano-structured lead(II) coordination polymers as precursors for preparation of lead(II) oxide nanoparticles

Crystalline and nano-structures of two novel Pb(II) coordination polymers, [Pb2(2-pyr)4(MeOH)]n (1), {2-Hpyr = 2-pyrazinecarboxylic acid} and [Pb(2-quc)2]n (2), {2-Hquc = 2-quinolinecarboxylic acid} are synthesized via thermal gradient and sonochemical methods, respectively. X-ray diffraction is used to clarify the structure of the single crystals of the newly synthesized 1 and 2 polymers. The nano-structured polymers are also characterized via X-ray powder diffraction (XRD), scanning electron microscopy (SEM), IR spectroscopy and elemental analysis. The thermal stability of both crystalline and nanostructured 1 and 2 coordination polymers is closely investigated via thermal gravimetric (TGA) and differential thermal analyses (DTA), and the results are compared to show the effect of particle size on thermal stability of complexes. The compounds are then heated to 600 °C to produce PbO nano-particles. The resulting PbO is characterized through XRD and SEM analyses. Interestingly, PbO nanoparticles with different morphology and size are produced from calcination of the two coordination polymers.