title: Poly[hexa-aqua-bis(μ(3)-naphthalene-2,6-dicarboxyl-ato)(μ(2)-naphthalene-2,6-dicarboxyl-ato)diholmium(III)].
abstract: The crystal structure of the title compound, [Ho(2)(C(12)H(6)O(4))(3)(H(2)O)(6)](n), contains binuclear centrosymmetric {Ho(2)O(2)(CO(2))(4)(H(2)O)(6)} cores inter-connected via the naphthalene-2,6-dicarboxyl-ate (NDC(2-)) bridging ligands into a two-dimensional neutral plane net, ∞(2)[Ho(2)(NDC)(3)(H(2)O)(6)], exhibiting a typical (4,4)-topology. Inter-actions between adjacent layers are assured by a series of C-H⋯π contacts and a number of strong and highly directional O-H⋯O hydrogen bonds involving the coordinated water mol-ecules and neighbouring coordinated carboxyl-ate groups. One NDC(2-) bridging ligand has its centroid located at a crystallographic centre of inversion.
authors.forename: Filipe A
authors.initials: FA
authors.lastname: Almeida Paz
authors.forename: Jacek
authors.initials: J
authors.lastname: Klinowski