A series of d10 coordination polymers constructed with a rigid tripodal imidazole ligand and varied polycarboxylates: syntheses, structures and luminescence properties

Five novel Zn(II)/Cd(II) coordination polymers,[Zn-2(tib)(L-1)(mu(2)-OH)(HCOO)center dot 2H(2)O](n) (1), [Cd-2(tib)(2)(L-1)(NO3)(2)center dot 2H(2)O center dot 4DMF](n) (2), [Cd-2(tib)(2)(L-2)(NO3)center dot 2H(2)O center dot 4DMF](n) (3), [Cd(tib)(L-3)center dot H2O center dot 2DMF](n) (4) and [Cd-3(tib)(4)(L-4)center dot 5/2NO(3)center dot 1/2OH center dot 3DMF](n) (5) (tib = 1,3,5-tris(1-imidazolyl)benzene, H2L1 = terephthalic acid, H2L2 = isophthalic acid, H2L3 = 1,4-naphthalenedicarboxylic acid, H3L4 = (1 alpha, 3 alpha, 5 alpha)-1,3,5-cyclohexanetricarboxylic acid, DMF = N,N-dimethylformamide), have been synthesized under solvothermal conditions. In compound 1, two-dimensional (2D) Zn-tib layers are pillared by L1 to afford a (3,5)connected three-dimensional (3D) framework with topology (6(3))(6(9).8). Compound 2 displays a 2D + 2D -> 2D interpenetrated bi-layer array based on a 2D (3,4) network. Compound 3 is characterized as an infinite one-dimensional (1D) chain structure, which is further extended into a 3D supramolecular architecture via weak pi center dot center dot center dot pi stacking interactions. Compound 4 possesses a 3D 2-fold interpenetrated architecture with the Schlafli symbol (4(2).6(5).8(3))(4(2).6). Compound 5 features a fascinating petal shaped (3,5)-connected network with a (4(2).6.8(4).10(3))(3)(4(2).6)(3)(8(3))(2) topology which until now has never been documented. In this series of compounds, the diversity of the structures is tuned by the coordination geometries of the metal ions and the nature of the varied co-ligands. Furthermore, the luminescence properties of compounds 1-5 at room temperature have also been studied in detail.