Poly[[hexa­aqua­tris­[μ(2)-2,5-dihy­droxy-1,4-benzoquinona­to(2−)]diholmium(III)] octa­deca­hydrate]

In the polymeric title compound, {[Ho(2)(C(6)H(2)O(4))(3)(H(2)O)(6)]·18H(2)O}(n), the Ho(III) ion is nine-coordinated by six O atoms derived from three bidentate 2,5-dihy­droxy-1,4-benzoquinonate (DHBQ(2−)) ligands and three O atoms from three water mol­ecules. The Ho(III) ions are connected via three ligands, resulting in the formation of a two-dimensional honeycomb layer parallel to the ab plane. The layer is racemic in which Δ- and Λ-coordination geometries around Ho(III) ions are alternately arranged. The asymmetric unit comprises a third of a Ho(III) ion, located on a threefold axis, one-half of a DHBQ(2−) ion, located on a centre of inversion, one coordinated water mol­ecule and three uncoordinated water mol­ecules.