catena-Poly[[silver(I)-μ-1,3-bis(4-pyridyl)propane] hemi(naphthalene-1,5-disulfonate) dihydrate]: a three-dimensional metallo-supramolecular sandwich lamellar network.

The title compound, {Ag(C(13)H(14)N(2))(0.5)·2H(2)O}(n), (I), features a three-dimensional supramolecular sandwich architecture that consists of two-dimensional cationic layers composed of polymeric chains of silver(I) ions and 1,3-bis(4-pyridyl)propane (bpp) ligands, linked by Ag···Ag and π-π interactions, alternating with anionic layers in which uncoordinated naphthalene-1,5-disulfonate (nds(2-)) anions and solvent water molecules form a hydrogen-bonded network. The asymmetric unit consists of one Ag(I) cation linearly coordinated by N atoms from two bpp ligands, one bpp ligand, one half of an nds(2-) anion lying on a centre of inversion and two solvent water molecules. The two-dimensional {Ag(bpp)}(n) cationic and {(nds)·2H(2)O}(n) anionic layers are assembled into a three-dimensional supramolecular framework through long secondary coordination Ag···O interactions between the sulfonate O atoms and Ag(I) centres and through nonclassical C-H···O hydrogen bonds.