Ultrasound-Promoted Synthesis and Characterization of Nanoparticles of Coordination Polymer [Co2(pydc)2(H2O)6]n.2nH2O

Abstract

Nanoparticles of coordination polymer [Co2(pydc)2(H2O)6]n.2n H2O [H2pydc = pyridine-2,5-dicarboxylic acid] have been synthesized by sonochemical method and characterized by elemental analysis, infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, DLS particle size analysis and TGA/DTA. The structure of single crystalline coordination polymer developed from nanosized coordination polymer was determined by X-ray crystallography. The XRPD studies reveal that nanoparticles of coordination polymer [Co2(pydc)2(H2O)6]n.2nH2O have same structure as that of bulk single crystalline polymer. The coordination polymer posses a 1-D chain like extended structure with binuclear cobalt(II) nodal unit. The coordination geometry around two cobalt atom Co(1) and Co(2) can be described as slightly distorted octahedron. The average particle size of nanoparticles calculated by using least square method of Modified Scherrer formula was found ~27 nm. The nanoparticles are composed of polyhedral blocks with definite edges. Dynamic Light Scattering (DLS) measurements show a narrow size distribution. The nanoparticles are thermally stable up to 352 K and thereafter decompose in well defined steps.