Nanoparticles of a two-dimensional coordination polymer, {[Pb(L)(mu(1.1)-NCS)(H2O)]}(n) (1), (L- = 1H-1,2,4-triazole-3-carboxylate), have been synthesized by a sonochemical process and characterized by scanning electron microscopy. X-ray powder diffraction, IR spectroscopy and elemental analyses. The thermal stability of compound 1 both its bulk and nano-size has been studied by thermal gravimetric (TG) and differential thermal (DTA) analyses and compared each other. Concentration of initial reagents effects and the rote of power ultrasound irradiation on size and morphology of nano-structured compound 1, have been studied. Calcination of the single crystals and nano-sized compound 1 at 400 degrees C under air atmosphere yields mixture of PbS and Pb-2(SO4)O nanoparticles. Results show that the size and morphology of the PbS and Pb-2(SO4)O nanoparticles are dependent upon the particles size of compound 1. A decrease in the particles size of compound 1 leads to a decrease in the particles size of the PbS and Pb-2(SO4)O. (C) 2011 Elsevier B.V. All rights reserved.