Structural properties and topological diversity of polymeric Ag(I)-hexamethylenetetramine complexes: Self-assembly of three novel two-dimensional coordination networks and their supramolecular interactions

The self-assembly of polymeric open networks from different Ag(I) salts and the potentially tetradentate ligand hexamethylene-tetramine (hmt) has revealed a variety of possible structural motifs, depending on the reagent ratios and the counterions, that are discussed in comparison. Three new Ag(I) coordination polymers are here described, namely [Ag-2(mu(4)-hmt)(Tos)(2)] (Tos = p-toluenesulfonate) (1), [Ag-2(mu(3)-hmt)(2)(CF3SO3)(H2O)](CF3SO3) . H2O (2), and [Ag-3(mu(3)-hmt)(2)(H2O)(4)](PF6)(3) (3), that contain two-dimensional infinite layers of different types. Crystal data: 1 C20H26Ag2N4O6S2, monoclinic, C2/c, Z = 4, a = 9.482(3) Angstrom, b = 8.539(3) Angstrom, c = 28.461(10) Angstrom, beta = 91.75(2)degrees, V = 2303.3(13) Angstrom(3), R = 0.043 (I > 2 sigma(I)); 2 C14H28Ag2F6NO8S2, monoclinic, P2(1)/c, Z = 4, a = 6.429(2) Angstrom, b = 25.247(3) Angstrom, c = 16.162(2) Angstrom, beta = 91.54(2)degrees, V = 2622.4(9) Angstrom(3), R = 0.050 (I > 2 sigma(I)); 3 C12H32Ag3F18N8O4P3, monoclinic, C2/c, Z = 4, a = 16.675(4) Angstrom, b = 11.102(5) Angstrom, c = 18.455(3) Angstrom, beta =111.48(2)degrees, V = 3179.2(17) Angstrom(3), R = 0.040 (I > 2 sigma(I)). Compound 1 is composed of layers of square grids, with the silver ions acting as spacers and interacting with the anions through Ag-O contacts and also via pi bonds with the aromatic rings. Compound 2 consists of layers of hexagons, with alternate triconnected Ag(I) ions and tridentate hmt ligands, while compound 3 contains layers of larger hexagonal meshes, with sis hmt ligands at the vertices and six biconnected silver atoms as spacers. The latter two species give rise, via hydrogen-bond bridges involving coordinated water molecules, to three-dimensional arrays of new topologies. (C) 2000 Academic Press.