A fourfold interpenetrating diamondoid three-dimensional coordination polymer: poly[[[μ2-1,2-bis(pyridin-4-yl)ethene-κ2N:N'](μ2-5-hydroxyisophthalato-κ2O1:O3)zinc(II)] 1,2-bis(pyridin-4-yl)ethene hemisolvate].

In the title compound, {[Zn(C8H4O5)(C12H10N2)]·0.5C12H10N2}n or {[Zn(HO-BDC)(bpe)]·0.5bpe}n [HO-H2BDC is 5-hydroxyisophthalic acid and bpe is 1,2-bis(pyridin-4-yl)ethene], the asymmetric unit contains a Zn(II) atom, one HO-BDC ligand, one coordinated bpe ligand and half a noncoordinating bpe molecule with crystallographic inversion symmetry. Each Zn(II) centre is four-coordinated by two O atoms from two distinct HO-BDC ligands and two N atoms from two different bpe ligands in a ZnO2N2 coordination environment. The three-dimensional topology of the title compound corresponds to a fourfold interpenetrating diamondoid coordination polymer network, with the uncoordinated bpe ligands located in the cavities, hydrogen bonded to the main network via the hydroxy group of the HO-H2BDC ligand.