Three novel metal−organic frameworks (MOFs), |(C3H7NO)2(H2O)|[Zn3(C10H5N3O4)3(C3H7NO)2] (1), |(H2O)5(H3O)(NO3)|[Nd2(C10H5N3O4)3(H2O)4] (2), and |(H2O)2|[Nd3(C10H5N3O4)3(C10H4N3O4)] (3), based on the T-shaped tripodal ligands 2-(pyridine-4-yl)-1H-4,5-imidazoledicarboxylic acid and 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid (H3PyImDC), have been constructed under solvo-/hydrothermal conditions. The diverse coordination modes of H3PyImDC ligands have afforded the assembly of three novel compounds. In compound 1, two oxygen atoms and three nitrogen atoms of the H3PyImDC ligand, a T-shaped linker, coordinate to two zinc centers to form a novel bbm net with two distinct channels along the [100] and [001] directions. In compound 2, H3PyImDC ligands coordinate to neodymium centers to form a ladder-like chain which then interacts with a water molecules chain via hydrogen-bondings to construct a 3D supermolecular structure. In compound 3, H3PyImDC ligands, a T-shaped linker, coordinate to neodymium centers to form a (3,6)-connected net with an ant topology. In compounds 1−3, the two H3PyImDC ligands exhibit different coordination modes with zinc and neodymium centers, which afforded the expected structural diversity. Additionally, all three compounds exhibit strong fluorescence emissions in the solid state at room temperature.

The assembly of Cu(CH 3 COO) 2 3 H 2 O and pyridine-4,5-imidazoledicarboxylic acid (H 3 PyImDC) under solvothermal conditions in the presence of different organic templates yielded two three-dimensional chiral frameworks, |(C 3 H 10 N 2 )(C 3 H 7 NO) 0.5 -(H 2 O) 2 |[Cu II C 10 H 5 O 4 N 3 ] (1) and |(C 4 H 9 NO) 0.5 (H 2 O) 8 |[Cu II 2 Cu I (C 10 H 5 O 4 N 3 ) 2 (C 10 H 6 O 4 N 3 )] ( 2). Both of the compounds crystallized in the cubic, P4 3 32 space group and possessed open helical channels in the frameworks. To the best of our knowledge, compounds 1 and 2 present the first synthesized MOFs with a bmn and lcy-a net. Further characterization of the two compounds has been performed, including X-ray powder diffraction, inductively coupled plasma analysis, CHN, IR spectra, fluorescence spectra, X-ray photoelectron spectroscopy spectrum and thermogravimetric-differential thermal analysis.

No abstract

Three metal-organic frameworks, [Mn(bpydc)]DMA (JLU-Liu11), [Co(bpydc)DMSO](DMSO)(H2O) (JLU-Liu12) and [Co(bpydc)H2O]H2O (JLU-Liu13), have been solvothermally synthesized by reacting a T-shaped linker, 2,2′-bipyridyl-5,5′-dicarboxylic acid (H2bpydc) ligand with transition metals. These compounds exhibit three different types of structures. In JLU-Liu11, two oxygen atoms and two nitrogen atoms of the H2bpydc ligand coordinate to five manganese centers to form an ant net, and JLU-Liu11 displays two types of helical chains with opposite helical directions, which are composed of vertex-sharing 4-rings propagating along [100] direction. In JLU-Liu12, H2bpydc ligands coordinate to cobalt centers to form a new (3, 3)-connected net with two different tiles (6.12 4 ) and (6 2 .12 6 ). In JLU-Liu13, H2bpydc ligands coordinate to cobalt centers to form a two-dimensional layer which then interact with terminal water molecules via hydrogen bonds to construct a three-dimensional supramolecular structure, JLU-Liu13 shows exceptional stability in water. Additionally, the magnetic properties of all compounds have been studied.

Four three-dimensional (3D) Cd-based metal–organic frameworks (MOFs), [Cd(pyip)­(dmf)] (1), [Cd(pyip)(doa)] (2), [Cd(pyip)­(pz)] (3) and [Cd(pyip)­(bipy)(H2O)0.5] (4) (dmf = N,N′-dimethylformamide, doa = 1,4-dioxane, pz = pyrazine, bipy = 4,4′-bipyridine) have been rationally designed and systematically synthesized by using 5-(pyridine-4-yl)isophthalic acid (H2pyip) and Cd(NO3)2·4H2O under solvothermal conditions. Compound 1 possesses a mineral-like 3,6-connected rtl network, and compounds 2–4 exhibit a 3,5-connected interpenetrating hms network constructed with 2-fold layers and bridging coligands pillars (doa, pz, and bipy), respectively. In compounds 2–4, doa, pz, and bipy act as pillars to extend the distance between the two layers from 7.34 to 11.36 Å, and the different conformations and lengths of the coligands have influenced the angles between the bridging ligands and the layers. Additionally, the four compounds exhibit strong luminescent emissions in the solid state at room temperature, and the latter three compounds exhibit robust architectures as evidenced by their permanent porosity and high thermal stability.