Poly[hexaaquabis(mu(3)-naphthalene-2,6-dicarboxylato)(mu(2)-naphthalene-2,6-dicarboxylato)diholmium(III)]

The crystal structure of the title compound, [Ho-2(C12H6O4)(3)(-)( H2O)(6)](n), contains binuclear centrosymmetric {Ho2O2(CO2)(4)(-)( H2O)(6)} cores interconnected via the naphthalene-2,6-dicarboxylate (NDC2-) bridging ligands into a two-dimensional neutral plane net, infinity(2)[Ho-2(NDC)(3)(H2O)(6)], exhibiting a typical (4,4)-topology. Interactions between adjacent layers are assured by a series of C-H center dot center dot center dot pi contacts and a number of strong and highly directional O-H center dot center dot center dot O hydrogen bonds involving the coordinated water molecules and neighbouring coordinated carboxylate groups. One NDC2-bridging ligand has its centroid located at a crystallographic centre of inversion.