A unique open inorganic-organic framework with alternate hexa-and penta-coordinate cobalt(II) sites. Synthesis, crystal structure and magnetic properties of [Co_3(C_4H_4O_4)_2.5(OH)]_n·0.5nH_2O

摘要

A three-dimensional open-framework with unprecedented alternate hexa-and penta-coordinate cobalt(II) siets was obtained from the hydrothermal reaction of cobalt nitrae and succinate in a basic solution. Of the four crystallographically independent Co(II) atoms in the crystal structure of this compound, three are hexa-coordinated and one penta-coordinated. The cobalt(II) atoms are linked by edge-sharing CoO_n (n = 5 or 6) polyhedrons. The temperature dependence of the magnetic susceptibility of this compound shows strong antiferromagnetic interaction between the metal atoms.