Synthesis, characterization and magnetic properties of disk-shaped particles of a cobalt alkoxide:: CoII(C2H4O2)

A cobalt alkoxide, Co(OCH2CH2O), has been prepared from the reaction of cobalt acetate with ethanediol. This compound crystallizes as disk-shaped particles with diameter and thickness in the 0.4-1 mum and 100-250 nm ranges, respectively. Structural characterization (X-ray and electron diffraction) shows a layered arrangement with a brucite-like structure presenting a turbostratic disorder. The interlayer spacing and the Co...Co distance within the layer are c = 8.27 Angstrom and a = 3.09 Angstrom, respectively. UV-visible spectroscopy studies established that the Co(II) ions are located on octahedral sites. IR spectroscopy showed that the ethylene glycolate anions (OCH2CH2O)(2-) chelate the Co(II) cations. The magnetic properties of the compound were measured in the range of 2-300 K. Below 20 K, the compound exhibits 3D ferromagnetic order and the hysteresis loop shows a very high remanence-to-saturation ratio typical of a uniaxial magnetocrystalline anisotropy.