Zn(II) and Cd(II) Coordination Polymers Assembled from a Versatile Tecton 5-Nitro-1,2,3-benzenetricarboxylic Acid and N,N′-Donor Ancillary Coligands

Five novel zinc(II) and cadmium(II) metal-organic coordination polymers with a tricarboxyl tecton and N-donor ancillary ligands, {[Zn(Hnbta)(2,2'-bipy)]center dot H2O}(n) (1), {[Cd-3(nbta)(2)(2,2'-bipy)(2)(H2O)(2)]}(n) (2), {[Cd-3(nbta)(2)(bpa)(2)]}(n) (3), {[Zn-2(nbta)(OH)(bpa)(1.5)]center dot 2H(2)O}(n) (4), and {[Zn-3(nbta)(2)(bpp)(2)(H2O)(2)]}(n) (5) (H(3)nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, 2,2'-bipy = 2,2'-bipyridine, bpa = 1,2-bi(4- pyridyl)ethane, and bpp = 1,3-bi(4-pyridyl)propane), have been prepared and characterized by elemental analysis, IR spectra, and X-ray diffraction. Complex 1 has a two-dimensional (2D) bilayer supramolecular network constructed from one-dimensional (ID) zigzag coordination chains via pi center dot center dot center dot pi interactions, whereas 2 exhibits a three-dimensional (3D) supramolecular network assembled from ID coordination arrays through pi center dot center dot center dot pi interactions and weak C-H center dot center dot center dot O interactions. Complex 3 features a (4,5)-connected self-penetrating 3D coordination net with a (4(3).6(5).8(2))(4(3).6(2).8)(4(4).6(4).8(2))(4(5).6(5)) topology. The 3D framework of 4 can be described as a trinodal (4,5)-connected (3.4.5(3).6)(3.5(2).6(2).8(4).9)(3.4.5.8(3)) topology, which consists of 2D [Zn(nbta)] helical arrays and bpa pillars. Complex 5 has a 3D trinodal 4-connected (4.6(4).8)(4(4).6(2))(4(3).6(3)) topology. Moreover, thermal stabilities and luminescent properties of complexes 1-5 have also been investigated.