A square two-dimensional polymer of cobalt citrate cubanes

Abstract

The structure of the title complex, poly[dicaesium(I) hexaaquacobalt(II) [octaaquatetra-μ-citrato-hexacobalt(II)] dodecahydrate], {Cs(2)[Co(H(2)O)(6)][Co(6)(C(6)H(4)O(7))(4)(H(2)O)(8)]·12H(2)O}(n), at 100 (1) K is formed by layers of a square two-dimensional polymer composed of Co(II) citrate cubanes bridged by magnetically active six-coordinate Co(II) cations. The polymer has plane symmetry p4mm in the c-axis projection. The cubanes reside on sites of crystallographic symmetry 4, while the bridging Co(II) centres lie on twofold axes. The basic polymeric unit has a charge of 4-, balanced by two Cs(+) and a [Co(H(2)O)(6)](2+) (symmetry -4) cation, which lie in channels between the polymeric layers. Unligated water molecules, of which there are 12 per cubane, enter into an extended intralayer and layer-bridging hydrogen-bond pattern, which can be described in detail even though not all of the H atoms of the water molecules were located.