Formation of Three New Silver(I) Coordination Polymers Involving 1,2-Phenylenediacetic Acid via the Modulation of Dipyridyl-Containing Ligands

Three new silver(I) metal-organic frameworks (MOFs), namely, [Ag-2(pda)(bipy)(2)](n)center dot 4nH(2)O (1), [Ag-2(pda)-(dpe)(2)(H2O)](n)center dot 4nH(2)O (2), and [Ag(Hpda)(bpp)](n) (3), were prepared by hydrothermal reactions of silver(I) acetate with H(2)pda (H(2)pda = 1,2-phenylenediacetic acid) in the presence of different pyridyl-containing ligands (bipy = 4,4'-bipyridine, dpe = 1,2-di(4-pyridyl)-ethylene, and bpp = 1,2-bis(4-pyridyl)propane) and structurally characterized by single crystal X-ray diffraction. Complex I shows a two-dimensional (2D) four-connected network with it long topological vertex Schlafli symbol (4.6(2).4.6(3).6(4).6). Of particular interest, it new unreported octameric water cluster, (H2O)(8), which is comprised of a cyclic water tetramer and four dangling water monomers, exists in 1. And the pseudorotaxane motifs are formed by these octameric clusters and the [Ag-8(pda)(2)(bipy)(4)] loops. Complex 2 features it one-dimensional (1D) ladder-like chain structure, and the 2D networks, assembling by the combination of the pentameric water cluster, (H2O)(5), and pda dianions, are supported by the 1D polymeric chains to form an infinite three-dimensional (3D) supramolecular framework. Complex 3 is a highly puckered 2D (6,3) sheet and 2 (18) 6 topology Will, a further stacks via hydrogen bonding interlocks notated as R-2(2)(18) to afford a unique 3D 6(6) long topological vertex Schlafli symbol of (6.6(2).6.6(2).6.6(2)) but which is not a typical diamondoid network. The diverse arrangements of the complexes show the remarkable sensitivity of the Ag-1-H(2)pda system to the different dipyridyl ligands; that is to say, the subtle modulation of dipyridyl-containing ligand has a significant effect on the overall MOFs and the coordination modes of H2pda ligands. In addition, the properties of thermogravimetric analysis-differential scanning calorimetry, X-ray powder diffraction, and photoluminescent behaviors of the complexes have been also discussed.