3D Porous Metal-organic Framework Research Articles

A Copper-Organic Framework with Carboxylate Groups for Efficient C2-C3 Hydrocarbons Capture

Increasing the ligand size could enlarge the pore volume of MOFs, which could further increase the gas adsorption capacity. Inspired by this, we synthesized a porous 3D metalorganic framework [Cu2(L1)·(H2O)2] ·2H2O·3DMF·(CH3)2NH2] (NEM-5) with a high density of carboxylate groups and CuII sites, which exhibited large uptakes for C2H2 (65 cm3 g-1), C2H4 (48 cm3 g-1), C2H6 (64.7 cm3 g-1), C3H6 (68 cm3 g-1), and C3H8 (63.4 cm3 g-1) at room temperature. Compared with MOF 1, NEM-5 has a similar topology and larger pore volume, but the gas adsorption capacities are significantly reduced, which might be attributed to the large pore size and low framework density of NEM-5.

Porous Metal Organic Framework for the Chemical Fixation of CO2 and Operation Nursing Application Values on Postoperative Infection

A porous 3D metal–organic framework (MOF) with NbO topology was prepared at ambient temperature by utilizing the paddle wheel dinuclear secondary building units of Co2(COO)4 and tertiary amine groups as an active center. Its chemical formula is {[Co2(L)(H2O)2]·(3DMF)(4H2O)}n (1, H4L is 5, 5′-(piperazine-1,4-diyl)diisophthalic acid). The activated MOF 1 possesses a rich porous structure, high Langmuir and BET surface areas, and abundant Lewis acid (CoII) catalytic sites and tertiary amino groups. This catalyst is suitable for the synthesis of cyclic carbonates from epoxides and CO2 with TBAB catalyst under a no solvent or mild reaction. Its treatment activity on postoperative bacterial infection was also determined, and bacterial survival was calculated. Relative ftsZ expression in bacteria was measured by real time RT-PCR.

Realization of an Ultrasensitive and Highly Selective OFET NO2 Sensor: The Synergistic Combination of PDVT-10 Polymer and Porphyrin-MOF.

Organic field-effect transistors (OFETs) are emerging as competitive candidates for gas sensing applications due to the ease of their fabrication process combined with the ability to readily fine-tune the properties of organic semiconductors. Nevertheless, some key challenges remain to be addressed, such as material degradation, low sensitivity, and poor selectivity toward toxic gases. Appropriately, a heterojunction combination of different sensing layers with multifunctional capabilities offers great potential to overcome these problems. Here, a novel and highly sensitive receptor layer is proposed encompassing a porous 3D metal-organic framework (MOF) based on isostructural-fluorinated MOFs acting as an NO2 specific preconcentrator, on the surface of a stable and ultrathin PDVT-10 organic semiconductor on an OFET platform. Here, with this proposed combination we have unveiled an unprecedented 700% increase in sensitivity toward NO2 analyte in contrast to the pristine PDVT-10. The resultant combination for this OFET device exhibits a remarkable lowest detection limit of 8.25 ppb, a sensitivity of 680 nA/ppb, and good stability over a period of 6 months under normal laboratory conditions. Further, a negligible response (4.232 nA/%RH) toward humidity in the range of 5%-90% relative humidity was demonstrated using this combination. Markedly, the obtained results support the use of the proposed novel strategy to achieve an excellent sensing performance with an OFET platform.

Switchable electrical conductivity in a three-dimensional metal-organic framework via reversible ligand n-doping.

Redox-active metal–organic frameworks (MOFs) are promising materials for a number of next-generation technologies, and recent work has shown that redox manipulation can dramatically enhance electrical conductivity in MOFs. However, ligand-based strategies for controlling conductivity remain under-developed, particularly those that make use of reversible redox processes. Here we report the first use of ligand n-doping to engender electrical conductivity in a porous 3D MOF, leading to tunable conductivity values that span over six orders of magnitude. Moreover, this work represents the first example of redox switching leading to reversible conductivity changes in a 3D MOF.

Highly Connected Metal-Organic Framework Constructed from Heptanuclear SBUs: Structure, Topology, and Fluorescence

The novel porous 3D metal-organic framework, [Cd9(BTA)6(H2O)5]·5H2O (1) (BTA = benzene-1,3,5-tri-β-acrylate), has been synthesized under hydrothermal condition. The X-ray crystallography revealed that the compound 1 pertains to an orthorhombic crystal system with space group Ibca. The MOF constructed from a centro-symmetric hexagonal wheel-like anionic cluster [Cd7(O2C)18]4‒ and linked by semi-rigid BTA ligands, leading to an exceptionally complicated topology with point symbol of (42⋅6)6 (436⋅6105⋅812). Furthermore, it shows excellent thermo-stability in aqueous surroundings. Fluorescence of the compound was evaluated under ultraviolet light irradiation at room temperature. The compound can perform as a highly selective and sensitive luminescence sensor toward metal ions Al3+ and Fe3+ based on the luminous enhancing or quenching phenomenon in aqueous solutions. Thus the new crystalline solid material can be expected to have broad practical applications in detecting, sensing or other related fields.

Desulfurization by liquid phase adsorption: Role of exposed metal sites in metal-organic frameworks

A highly porous 3D metal-organic framework {H3[(Cd4Cl)3(ttpa)8(H2O)12]⋅nH2O}∞ (1) with a 3,8-connected framework (H3ttpa = tris-[4-tetrazolylphenyl]amine) was prepared by in situ chemical synthesis using solvothermal method. With the open metal sites, the complex 1 can act as an efficient adsorbent for the removal of benzothiophene (BT) and dibenzothiophene (DBT) from isooctane.

Enantioselective Separation over a Chiral Biphenol-Based Metal-Organic Framework.

A chiral porous 3D metal-organic framework (MOF) is constructed from an enantiopure carboxylate ligand of 1,1'-biphenol, which can be utilized as adsorbent for the separation of aromatic alcohols and sulfoxides with enantioselectivity of up to 99.4%. Single-crystal X-ray diffraction analysis reveals the binding sites and host-guest interactions clearly, providing microscopic insight into the origin of the enantiosorption in the framework.

3D porous metal-organic framework for selective adsorption of methane over dinitrogen under ambient pressure.

We report a highly porous 3D metal-organic framework (MOF) that shows potential for coal mine methane (CMM) capture.

Evidence of New Fluorinated Coordination Compounds in the Composition Space Diagram of FeF3/ZnF2–Hamtetraz-HFaq System

The exploration of the composition space diagram of the FeF3/ZnF2–Hamtetraz-HFaq system (Hamtetraz = 5-aminotetrazole) by solvothermal synthesis at 160 °C for 72 h in dimethylformamide (DMF) has evidenced five new hybrid fluorides (1–5); the structures are characterized from single crystal X-ray diffraction data. [Hdma]·(ZnFeIII(H2O)4F6) (1) and [Hdma]·[Hgua]2·(FeIIIF6) (2) contain anionic inorganic chains (1) or isolated octahedra (2) weakly hydrogen bonded (Class I hybrids) to dimethylammonium (Hdma) and/or guanidinium (Hgua) cations which are produced from the tetrazole ligand and solvent decomposition. [Hdma]2·[Hgua]·[NH4]·[ZnFeIIIF5(amtetraz)2]2 (3), [Hdma]2·[Zn1.6FeII0.4FeIIIF6(amtetraz)3] (4), and [Hdma]·[Zn4F5(amtetraz)4] (5) are considered as Class II hybrids in which the (amtetraz)− anions are strongly linked to divalent metal cations via N–M bonds. In 3, ∞{[NH4]·[ZnFeIIIF5(amtetraz)2]2} layers are separated by [Hdma]+ and [Hgua]+ cations. 4 and 5 exhibit three-dimensional (3D) hybrid networks that contain small cavities where [Hdma]+ cations are inserted. A porous 3D metal–organic framework intermediate is evidenced from the thermogravimetric analysis and X-ray thermodiffraction of 5.

An unprecedented chiral porous 3D metal–organic framework self-assembled with 1D helical and double chain

A novel chiral metal–organic framework based on copper(II) and mixed ligands [Cu(tsgluO)(4,4-bipy)1.5]n·2.7nH2O (1) (H2tsgluO=N-tosyl-l-glutamic acid, 4,4-bipy=4,4-bipyridine) has been synthesized and structurally characterized by single-crystal X-ray diffraction. The X-ray diffraction revealed that complex 1 is formed via self-assembly of 1D right-handed helical chain and 1D ladder-like double chain, and the two different 1D chains are further interpenetrated to give rise to a 3D porous framework which consists of 1D channel along the a axes. Interestingly, the host framework encapsulates unique octameric water clusters.

A 3D MOF showing unprecedented solvent-induced single-crystal-to-single-crystal transformation and excellent CO2 adsorption selectivity at room temperature.

A water stable porous 3D metal-organic framework, [Cu3L2(μ3-OH)2(μ2-H2O)]·2DMA (1, mother crystal, H2L = 2,2'-dinitrobiphenyl-4,4'-dicarboxylic acid, DMA = N,N-dimethylacetamide), shows unprecedented irreversible solvent-induced substitutions of bridging aqua ligands and guest-exchanges in single-crystal-to-single-crystal (SCSC) transformations at room temperature (RT), producing quantitatively three daughter crystals, [Cu3L2(μ3-OH)2]·2S (2: 2A, S = acetone; 2B, S = 2-propanol; 2C, S = 2-butanol), which exhibit reversible interconversion by guest-exchanges at RT in SCSC transformations. MOF 1 shows excellent separation selectivity (128) of CO2/N2 at RT and is a better sorbent of micro-solid-phase extraction (μ-SPE) than currently known benchmark ZIF-8.

Novel Functionalized Metal−Organic Framework Based on Unique Hexagonal Prismatic Clusters

The novel porous 3D metal-organic framework synthesized from fluorenone-2,7-dicarboxylate contains zinc-glycolate-carboxylate layers in which the unique hexagonal prismatic [Zn(6)(OCH(2)CH(2)O)(6)] clusters are connected by planar [Zn(3)(OCH(2)CH(2)O)(COO)(2)] motifs; the pore surface is furnished with carbonyl groups and open metal sites.

Design and construction of a microporous metal–organic framework based on the pillared-layer motif

A unique porous 3D metal–organic framework has been synthesized based on the insertion of heterogeneous pillars between 2D layers, the permanent porosity of which is confirmed by N2 adsorption isotherm measurement.

A chiral porous 3D metal–organic framework with an unprecedented 4-connected network topology

A novel homochiral 3D metal-organic framework [CdL2(H2O)2][ClO4]2.2DMF.3EtOH.5/3H2O, 1, (L =(R)-6,6-dichloro-2,2-diethoxy-1,1-binaphthyl-4,4-bipyridine) exhibits an unprecedented 4-connected network topology owing to the cis- configuration of the Cd coordination and possesses permanent porosity as demonstrated by TGA, XRPD, and CO2 adsorption isotherm studies.