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Two porous metal–organic frameworks (1 and 2) with a fsc topology based on mixed ligands have been assembled and characterized. The different pillared ligands (pyrazine for 1 and 4,4′-bipyridine for 2) significantly influence the pore size of the frameworks. Gas uptake measurements reveal that complex 1 possesses higher H2, CO2, and CH4 uptake capacities than 2, although the surface area of 1 is lower than that of complex 2. These results further experimentally prove that the pore size plays an important role in gas uptake in porous MOFs, and the slit pore with a size of ∼6 Å exhibits stronger interactions with gas molecules. [ABSTRACT FROM AUTHOR]

Abstract: A novel metal-organic framework, [Zn2(OH)(Hcht)(4,4′-bpy)] n ·4nH2O (1) (H4cht=cyclohexane-1,2,4,5-tetracarboxylic acid and 4,4′-bpy=4,4′-bipyridine), was synthesized by the hydrothermal reaction of Zn(NO3)2·6H2O, 4,4′-bipyridine, and cyclohexane-1,2,4,5-tetracarboxylic acid in the presence of sodium carbonate. The complex was obtained by controlling the ratio of the starting materials and a reaction temperature at 120°C and was characterized by IR, X-ray powder diffraction, thermogravimetric analysis, fluorescent spectrum, and single crystal X-ray diffraction. Single-crystal X-ray investigation reveals that the structure features a two-dimensional framework with novel coordination mode of Hcht ligand and all Hcht ligands exclusively convert to a sole conformation in the complex. IR spectrum reveals the characteristic absorption peaks of asymmetric stretching vibrations that result from the protonated and deprotonated carboxyl groups. Thermogravimetric analysis shows four clear courses of weight loss, which corresponds to the decomposition of different ligands. Fluorescent spectrum displays that complex 1 is a potential blue-luminescent material. [Copyright &y& Elsevier]

Graphical abstract In this work, the surface wettability of a zeolitic imidazolate framework (ZIF-8) mesh is successfully switched from hydrophilicity to hydrophobicity by surface ligand exchange for efficient separation of oil-water mixtures. Abstract The surface wettability of a zeolitic imidazolate framework (ZIF-8) mesh was successfully switched from hydrophilicity to hydrophobicity via surface ligand exchange aiming for oil-water separation for the first time. The ZIF-8 mesh after ligand exchange (ZIF-8-SLE mesh) exhibits superhydrophobicity that selectively allows the oil permeation, contrary to ZIF-8 mesh that only allows water to pass through. The high separation performance and recyclability of ZIF-8-SLE mesh show the great potential of this method in fabricating new MOF meshes, films or membranes for future practical oil-water related separations. [ABSTRACT FROM AUTHOR]

This work presents the construction of a porous lead-organic framework (UPC-10) with large channels of ∼24 Å. UPC-10 shows efficient adsorption of I2 and selective adsorption of some dyes containing the SO3− group. After the adsorption of dyes, UPC-10 exhibits a CO2 gas uptake ability. Furthermore, UPC-10 could be transformed into PbS in a H2S atmosphere, and the derived PbS manifests N2 and CO2 uptake abilities. [ABSTRACT FROM AUTHOR]

Three new mixed-ligand coordination networks, [Cd2(ADDA)(bipy)(H2O)2]·2H2O (1), [Zn(ADDA)(bipy)0.5]·NMP·2H2O (2), and [Co(ADDA)(bip)(H2O)2]·H2O (3) (bipy = 4,4′-bipyridine, bip = 1,4-di(1H-imidazol-1-yl)benzene, H2ADDA = 3,3′-(anthracene-9,10-diyl)diacrylic acid), have been synthesized based on 3,3′-(anthracene-9,10-diyl)diacrylate acid and different N-donor ligands under solvothermal conditions, and structurally characterized by single-crystal X-ray diffraction analyses, infrared spectroscopy (IR), elemental analyses, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). Topological analysis reveals that 1 features a rare 8-connected 3D ilc network with the point symbol of {4∧24.5.6∧3}; complex 2 possesses a 3D open framework based on the infinite Zn–(CO2) chain with the point symbol of {6∧2.8∧4}; while complex 3 shows a normal 2D 3-connected coordination network with hcb topology and the point symbol of {6∧3}. Besides, the luminescence properties of complexes 1 and 2 were also investigated. The results show that complex 2 bears rapid and selective sensing of Fe3+ in methanol suspension at room temperature. [ABSTRACT FROM AUTHOR]

Three metal organic coordination compounds, namely, {[Cd2(L1)4]2 ·9H2O} n ( 1), {[Zn(L1)2 ·2H2O]2 ·H2O} n ( 2), and [Cu(L2)2] n ( 3), [L1 = 3-chloro-2-(5 H-tetrazol-5-yl)pyridine; L2 = 3-chloropicolinic acid], were hydrothermally synthesized, in which L1 and L2 were synthesized by in situ reactions. X-ray diffraction analyses revealed that the 2D layer of complex 1 is built from a dinuclear CdII second building blocks, whereas complex 2 shows 0D structure, which is built based on two L1 ligands, one zinc ion, and two water molecules. 3 shows a 1D infinite rod-shaped chain. Additionally, the solid-state fluorescence properties for compound 1 and 2 are also presented. [ABSTRACT FROM AUTHOR]

Through a pillar-ligand extension strategy, a rare breathing behavior in polycatenated 2D→3D nets has been achieved. Three variants exhibit interesting sorption properties that range from non-breathing to breathing behaviors, which is influenced by the angles between the pillars and the single honeycomb layers. The increase in pillar length does not lead to an increase in polycatenation multiplicity, which is controlled by the length of intralayer tripodal carboxylate. It also does not induce obviously expanded interlayer separations but occupies much more the free voids, and as a consequence, a smaller pore volume is obtained. This suggests that in 2D→3D polycatenated bilayer metal-organic frameworks, the porosity is not always enhanced by increasing the length of the interlayer pillars with the intralayer linker remaining unchanged. [ABSTRACT FROM AUTHOR]

Twoisomorphous lanthanide–organic frameworks, Ln(BDC)1.5(DMF)(H2O) (Ln = Er (1), Tm (2)) have been synthesized based on 1,4-benzenedicarboxylicacid (H2BDC). Because of the 2-fold interpenetration, thepores are partly blocked and there are no significant gas adsorptionsfor these two interpenetrating nets. Through control over interpenetrationby applying an organic ligand with hindrance groups or replacing coordinatedsolvent molecules with a chelating ligand, three non-interpenetratinglanthanide–organic frameworks, Er2(BDC)3(phen)2·3H2O (3), Tm(TBDC)1.5(DMF)(H2O)·2H2O (4), Er2(TBDC)3(phen)2·4DMF·2H2O (5), possessing the same topology with 1and 2, have been synthesized and characterized.Further changing reaction conditions, three other porous lanthanide–organicframeworks with different structures with 1–5, Tm(BDC)1.5(H2O)·0.5DMF·C2H5OH·2H2O (6), Tm4(BDC)6(H2O)2(DMF)(C2H5OH)·2DMF·2H2O (7),and Sm(TBDC)1.5(phen)(H2O)·DMF·H2O (8), have been constructed. Gas sorption measurementsfor 5, 6, 7, and 8have been carried out and revealed that these materials possesspermanent porosity. The catalytic property for complex 6has also been studied. [ABSTRACT FROM AUTHOR]