Zn(II) and Cd(II) Coordination Polymers Assembled from a Versatile Tecton 5-Nitro-1,2,3-benzenetricarboxylic Acid and <i>N</i>,<i>N</i>′-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)]·H2O}n (1), {[Cd3(nbta)2(2,2′-bipy)2(H2O)2]}n (2), {[Cd3(nbta)2(bpa)2]}n (3), {[Zn2(nbta)(OH)(bpa)1.5]·2H2O}n (4), and {[Zn3(nbta)2(bpp)2(H2O)2]}n (5) (H3nbta = 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 (1D) zigzag coordination chains via π···π interactions, whereas 2 exhibits a three-dimensional (3D) supramolecular network assembled from 1D coordination arrays through π···π interactions and weak C−H···O interactions. Complex 3 features a (4,5)-connected self-penetrating 3D coordination net with a (43·65·82)(43·62·8)(44·64·82)(45·65) topology. The 3D framework of 4 can be described as a trinodal (4,5)-connected (3·4·53·6)(3·52·62·84·9)(3·4·5·83) topology, which consists of 2D [Zn(nbta)] helical arrays and bpa pillars. Complex 5 has a 3D trinodal 4-connected (4·64·8)(44·62)(43·63) topology. Moreover, thermal stabilities and luminescent properties of complexes 1−5 have also been investigated.