From 4'-Hydroxy-2,2':6',2''-Terpyridine Complex of Chromium(III) towards Cr2O3 Nanoparticles: Effects of the Calcination Temperature on the Particle Size and Morphology

A new chromium (iii) complex containing 4ʹ-hydroxy-2,2ʹ:6ʹ,2ʺ- terpyridine (tpyoh) has been prepared by the reaction of crcl3. 6h2o with tpyoh in the presence of metallic zinc to afford the new complex [crcl3(tpyoh)] (1). the complex 1 was used as a suitable precursor for the preparation of cr2o3 nanoparticles by the simple calcination method at three different annealed temperatures of 400, 600, and 800 ˚c. the structures of the products have been fully characterized by ir, powder x-ray diffraction (xrd), field emission scanning electron microscopy (fesem) and energy-dispersive x-ray spectroscopy (edx). the average particle size using scherrer’s equation is calculated to be about 27-36 nm. the results suggest that temperature is an effective way to tailor the morphology and crystallinity of the prepared nanoparticles. the photophysical properties and thermal gravimetric analysis (tga) of the complex 1 have also been investigated. the emission of 1 exhibits the high-energy intense π→π* intraligand and low-energy mlct transitions in dmso solution. the tga results show the stability of the complex up to 400 ˚c after stepwise decomposition of the coordinated ligands.