Synthesis and characterization of Co7(OH)12(C2H4S2O6)(H2O)2 -: a single crystal structural study of a ferrimagnetic layered cobalt hydroxide

A novel layered hydrotalcite-like material, Co-7(H2O)(2)(OH)(12)(C2H4S2O6), has been prepared hydrothermally and the structure determined using single crystal X-ray diffraction (a = 6.2752(19) Angstrom, b = 8.361(3) Angstrom, c = 9.642(3) Angstrom, alpha = 96.613(5)degrees, beta = 98.230(5)degrees, gamma = 100.673(5)degrees, R1 = 0.0551). The structure consists of brucite-like sheets where 1/6 of the octahedral sites are replaced by two tetrahedrally coordinated Co(II) above and below the plane of the layer. Ethanedisulfonate anions occupy the space between layers and provide charge balance for the positively charged layers. The compound is ferrimagnetic, with a Curie temperature of 33 K, Curie-Weiss theta of - 31 K, and a coercive field of 881 Oe at 5 K. (C) 2003 Published by Elsevier Ltd.