A square two-dimensional polymer of cobalt citrate cubanes.

The structure of the title complex, poly[dicaesium(I) hexa-aquacobalt(II) [octaaquatetra-mu-citrato-hexacobalt(II)] dodecahydrate], {Cs-2[Co(H2O)(6)][Co-6(C6H4O7)(4)(H2O)(8)]center dot 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) over bar, 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(H2O)(6)](2+) (symmetry (4) over bar) 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.