Search

Effective and rapid capture of heavy metal oxo-anions from wastewater is a fascinating research topic, but it remains a great challenge. Herein, benzimidazole and -CH

On the basis of an undeveloped asymmetrical pyridylcarboxylate ligand, 2-(2-carboxypyridin-4-yl)terephthalic acid (H3CPTA), an indium pyridylcarboxylate framework, [(Me)2NH2]1.5[In1.5(CPTA)2]·5.5NMF·6H2O (1), is synthesized under solvent thermal conditions. 1 displays a 3D anionic framework with a large void space, which contains open square channels with a cross section of 14.6 A and a pore surface decorated with carboxylic oxygen atoms. Depending on the anionic skeleton and high water stability, 1 exhibits high adsorption selectivity and capacity for cationic dyes in aqueous solution. Furthermore, the luminescence performance illustrates that 1 has selectivity and sensitivity to nitenpyram with good recyclability.

Solvothermal reactions of Co(NO3)2·6H2O, 3-amino-1,2,4-triazole, and 1,2,4,5-benzenetetracarboxylic acid afforded a Co-MOF: {[Co2(Hatz)(bta)]·H2O}n. Furthermore, a unique metal–organic-framework-ba...

Several new isostructural lanthanide metal-organic frameworks (Ln-MOFs), {[Ln

A bifunctional ligand strategy for modification of the functional pores is of great significance in the structural design of metal-organic frameworks (MOFs). Herein, a new 2-fold interpenetrated "pillared-layer" 3D Co-MOF, {[Co(HL)(4,4'-bipy)]·DMF·2H2O}n (1), was successfully synthesized by using two kinds of ligands, imidazolecarboxylic acid and pyridine. The metal-carboxylic layers are pillared by the 4,4'-bipy ligand, displaying a 3D framework with rectangular 3D channels (high BET surface of 190.9 m2 g-1 and maximum aperture of 3.9 A) that are decorated with abundant uncoordinated N and O atoms. 1 shows good water stability and thermal stability (320 °C). The proper pores and active sites endowed 1 with a selective adsorption of Congo red in aqueous solution. In addition, a high CO2 adsorption capacity and an excellent CO2 chemical conversion were observed.

Utilizing 5,5′-oxidiisophthalic acid (H4odip) ligand, one 3D framework {[Ni2(odip)(H2O)4(DMF)]·DMF·2H2O}n (1) with a rare 3-nodal (3,3,4)-connected topological net based on two types of Ni12(odip)1...

With the aid of a pyridyl tetracarboxylate ligand, 2,5-bis(2',5'-dicarboxylphenyl)pyridine (H4L), two indium-organic frameworks, [In2(L)(OH)2]·2DMF·2H2O (1) and [Me2NH2][In(L)]·2.5NMF·4H2O (2), with (6,8)- and (4,4)-connected nets have been constructed in different solvent systems. Both 1 and 2 exhibit high thermal and chemical stability. Gas sorption behavior of 1 and 2 for N2, C2H2, C2H4, CO2, and CH4 indicate excellent separation selectivities of C2Hx/CH4 and CO2/CH4. Furthermore, 1 possesses a high density of Bronsted sites and shows efficient catalytic conversion for CO2 cycloaddition with epoxides. Meanwhile, luminescence investigations reveal that 2 can detect nitrofurazone efficiently.

Metal-organic frameworks (MOFs) with zeolitic structure process fantastic structural metrics and display excellent applications in many aspects; however, they are difficult to assemble. Herein, on the basis of a tetrahedral Zn

Based on the mixed carboxylate ligands synthesis strategy, an indium-organic framework, (Me2NH2)1.5[In1.5(FBDC)(BDC)]·2.5NMF·CH3CN (1) has been constructed by using the mixed (2,5-di(2',5'-dicarboxylphenyl)-difluorobenzene (H4FBDC) and terephthalic acid (H2BDC). Compound 1 contains a 3D intersecting pore system which surface is modified by F atoms, and it has excellent stability in pH = 2-12 aqueous solutions. The activated 1 shows high separation for C2H2/CO2 and C2H2/CH4. Moreover, 1 not only has strong luminescence but also has the high selectivity and sensibility of fluorescence detection to nitrofurazone (NZF) in antibiotic sensing experiments, which can be used as a luminescence sensor for NZF detection.

Three new pairs of 2-fold interpenetrated and self-entangled three-dimensional isostructural porous metal-organic frameworks (MOFs), [Zn(L1)(x)0.5]·0.5H2O (x = bipy for 1, bpa for 2, and bpe for 3) and [Zn(L2)(x)0.5]·0.5H2O (x = bipy for 4, bpa for 5, and bpe for 6) [bipy = 4,4'-bipyridine, bpa = 1,2-bis(4-pyridyl)ethylene, and bpe = 1,2-bis(4-pyridyl)ethylene], have been created and fine-tuned via similar skeleton ligands 2-(imidazol-1-yl)terephthalic acid (H2L1) and 2-(1H-1,2,4-triazol-1-yl)terephthalic acid (H2L2) and N-auxiliary coligands with different linking groups. Interestingly, the porosities of the MOFs can be effectively increased via the insertion of -CH2CH2- or -CH═CH- spacers into the N-auxiliary bipy ligand. As a result, complexes 5 and 6 displayed highly enhanced CO2 uptake capacities. Furthermore, complex 5 also had a higher C2/C1 selectivity as well as great CO2 cycloaddition efficiency.

The new indium-based organic framework {(Me2NH2)[In(BDPO)]·DMF·2H2O}n (1) was successfully constructed by using the oxalamide group modified ligand N,N'-bis(isophthalic acid)oxalamide (H4BDPO). This framework presents a 2-fold interpenetrating structural characteristic, and the unique polar pore environment leads to a high capture ability for CO2, C2Hn and CH3OH and good separation ability for CO2 and C2Hn over CH4 as well as for CH3OH over C2H5OH, which was further verified by an ideal adsorbed solution theory (IAST) calculation. Theoretical simulations pointed out the possible adsorption sites of different adsorbed gases in 1. In addition, the excellent chemical stability and strong luminescence of 1 give it an effective selective detection ability for 2,6-dichloro-4-nitroaniline (DCN) in water with a low detection limit of 3.85 ppm, and the detection mechanism is discussed in detail.

To construct desired metal–organic framework (MOF) sensors, the predesigned functionalized ligands 2,5-bis(2′,5′-dicarboxylphenyl)pyridine (L-N) and 2,5-bis(2′,5′-dicarboxylphenyl)difluorobenzene (...

An interpenetrated indium pyridylcarboxylate framework, [NH2(CH3)2][In(L)2]·2.5DMF·5H2O (1), has been synthesized by employing a pyridylcarboxylate ligand, 4-(3-carboxylphenyl)picolinic acid (H2L), and an In3+ ion, with both chemical stability and framework flexibility. The desolvated 1 exhibits an uncommon breathing sorption behavior and shows highly selective adsorption for C2H2, C2H4, and CO2 over CH4. Furthermore, 1 shows rapid and higher adsorption efficiency for methylene blue and neutral red in aqueous solution.

Owing to the rapid increase of Hg(II) ions in water resources, the design and development of new adsorbents for Hg(II) removal are becoming a significant challenge in environmental protection. Herein, a thiol-functionalized metal-organic framework (SH-MiL-68(In)) was successfully prepared through a post-synthesis modification procedure, and the framework intactness and porosity were well maintained after this process. SH-MiL-68(In) exhibited selective adsorption performance for Hg(II) ions in water. Meanwhile, SH-MiL-68(In) also shows a high adsorption capacity (450 mg g-1), large adsorption rate (rate constant k2 = 1.25 g mg-1 min-1), and good recycling of adsorption capacity toward Hg(II) ions. The excellent adsorption performance resulted from the strong binding interactions between -SH soft basic groups and Hg(II) soft acidic ions.

By employing a pyridyl-decorated dicarboxylic acid ligand, 3-(2′,5′-dicarboxylphenyl)pyridine acid (H2dcpy), a three-dimensional In3+-based metal–organic framework, H3O[In3(dcpy)4(OH)2]·3DMF·4H2O (1), with a good chemical stability toward acid and base has been synthesized. The compound 1 shows an uncommon (3,8)-connected tfz-d; UO3 topological net based on linear In3(COO)4(OH)2 clusters and also contains one-dimensional open channels. Particularly, 1 contains two types of dcpy2– linkers, in which the pyridyl group in one participates in coordination with the In3+ ion, whereas that in the other is uncoordinated but hangs in the inner sides of the channels as functionalized sites. Gas adsorption experiments demonstrate that 1 is able to selectively adsorb C2H2, C2H4, and CO2 over CH4. Simultaneously, 1 shows a highly selective and sensitive fluorescence detection toward Fe3+ ion in water with good recyclability.

To comparably analyze the influence of a porous environment on the gas adsorption in MOFs, based on an imidazole-decorated MOF, {[Zn(imtp)]·DMA·1.5H2O}n (1-im, H2imtp = 2-(imidazol-1-yl) terephthalic acid), an analogue MOF, {[Zn(tztp)]·DMA}n (1-tz, H2tztp = 2-(1H-1,2,4-triazol-1-yl) terephthalic acid) has been synthesized by replacing imidazole with triazole motifs. The two MOFs are isostructural frameworks containing 1D channels; however, they possess different porous wall environments. The open nitrogen-decorated channels in 1-tz lead to significantly enhanced C2H6 (76.5 cm3 g–1) and C2H4 (73.1 cm3 g–1) uptakes at 298 K and 1 atm, which are 5 times of the adsorption amounts of C2H6 and C2H4 in 1-im that is the absence of exposed N atoms in the channels. Furthermore, the activated 1-tz also reveals higher adsorption selectivities for C2H6 and C2H4 over CH4. The different sorption properties were further uncovered by theoretical simulations.

A bifunctional ligand strategy for modification of the functional pores is of great significance in the structural design of metal-organic frameworks (MOFs). Herein, a new 2-fold interpenetrated "pillared-layer" 3D Co-MOF, {[Co(HL)(4,4'-bipy)]·DMF·2H

Based on the mixed carboxylate ligands synthesis strategy, an indium-organic framework, (Me

Three new pairs of 2-fold interpenetrated and self-entangled three-dimensional isostructural porous metal-organic frameworks (MOFs), [Zn(L1)(x)

Utilizing the oxygen-bridged 5,5′-oxidiisophthalic acid (H4L) linker, one Co(II)-based 3D porous MOF {[Co5(L)2(OH)2(OH2)2(H2O)4]·2DMF·H2O}n (1) with pentanuclear [Co5(μ3-OH)2(μ2-OH2)2]8+ cluster was prepared. The glassy carbon electrode was modified by 1, and the obtained electrode revealed electrocatalytic performance for glucose oxidation. The porous MOF matrix is beneficial for dispersing Ag nanoparticles evenly in the interior cages or channels, so Ag@1 composite composed of both Ag nanoparticles and MOF was further prepared through deposition-reduction method to enhance electrocatalytic activity. The result demonstrates that the glucose oxidation by Ag@1 was greatly increased with low detection limit (1.32 μM) and good selectivity and sensitivity (0.135 μA μM–1), which promote the application of MOF-template porous composites as advanced electrochemical sensor materials. Furthermore, 1 shows an interesting magnetic spin-glass slow dynamics for the existing of peculiar pentanuclear Co(II) clusters.