Novel zinc phosphate topologies defined by organic ligands

Six new zinc phosphates [C18H20N4][Zn-4(HPO4)(4)(H2PO4)(2)(C18H18N4)(3)]center dot 2H(2)O (1), [Zn-4(HPO4)(4)(C18H18N4)(3)]center dot 4H(2)O (2), [Zn-3(HPO4)(3)(H2PO4)(C22H22N8)(0.5)(C22H24N8)(0.5)] (3), [Zn-2(HP04)(2)(C18H16N4)] (4), [Zn(HPO4)(C18H14N2)] (5), and [Zn-2(HPO4)(2)(C12H10N4)] (6) have been synthesized under mild hydrothermal conditions in the presence of 1,4-bis(N-benzimidazolyl)butane (L1), 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene (L2), 1,4-bis(imidazol-1-ylmethyl)naphthalene (L3), 9-(imidazol-1-ylmethyl)anthracene (L4), and 1,4-bis(1-imidazolyl)benzene (L5), respectively, and their structures were determined by X-ray crystallography. Compound 1 exhibits a unique inorganic motif of isolated 8-rings interconnected by L1. Compound 2, also formed from L1, contains a previously unobserved chain structure composed of edge-sharing 4-rings and 8-rings. Compound 3, prepared from L2, possesses an unusual one-dimensional framework, which is composed of vertex-sharing 4-rings and triple fused 4-rings. The inorganic portions of 4, 5, and 6 each adopt a layer structure. The sheets in 4 and 5 have a 4.8(2) topology, and in 6, a 63 topology is observed. The zinc atoms in compounds 1-6 are all tetrahedrally coordinated by a combination of phosphate groups and organic ligands. Potential relationships between the inorganic motifs reported in the present study are identified. These are indicative of a possible pattern of self-assembly of zinc and phosphorus tetrahedra and indicative of the role of the organic ligands in the formation of hybrid structures.