In this paper, we report a new method for the synthesis of spherical CoO nanoparticles using a new metal-organic framework of Co(II). Nano particles of a coordination polymer compound, [Co(3,5-DNBA)]n (1) (L- = 3,5-dinitro benzoic acid) was synthesized and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and IR spectroscopy. The thermal stability of compound 1 has been studied by thermal gravimetric (TG) and differential thermal analyses (DTA), and UV-vis spectroscopy. In addition, compound 1 was used as a precursor for the synthesis of Cobalt oxide nano-particles. Two pathways, the first sonochemical process, and the second, hydrothermal method were used for preparing the mentioned nano-particles. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and IR spectroscopy were used to characterize the CoO nano-structures. Experimental results showed that the morphology of the CoO nanoparticles is spherical and the size of the nanoparticles is dependent on the particle size of compound 1. تفاصيل المقالة