Indium-organic Framework Research Articles

Defect-engineered indium-organic framework displays the higher CO2 adsorption and more excellent catalytic performance on the cycloaddition of CO2 with epoxides under mild conditions.

In order to achieve the high adsorption and catalytic performance of CO2, the direct self-assembly of robust defect-engineered MOFs is a scarcely reported and challenging proposition. Herein, a highly robust nanoporous indium(III)-organic framework of {[In2(CPPDA)(H2O)3](NO3)·2DMF·3H2O}n (NUC-107) consisting of two kinds of inorganic units of chain-shaped [In(COO)2(H2O)]n and watery binuclear [In2(COO)4(H2O)8] was generated by regulating the growth environment. It is worth mentioning that [In2(COO)4(H2O)8] is very rare in terms of its richer associated water molecules, implying that defect-enriched metal ions in the activated host framework can serve as strong Lewis acid. Compared to reported skeleton of [In4(CPPDA)2(μ3-OH)2(DMF)(H2O)2]n (NUC-66) with tetranuclear clusters of [In4(μ3-OH)2(COO)10(DMF)(H2O)2] as nodes, the void volume of NUC-107 (50.7%) is slightly lower than the one of NUC-66 (52.8%). However, each In3+ ion in NUC-107 has an average of 1.5 coordinated small molecules (H2O), which far exceeds the average of 0.75 in NUC-66 (H2O and DMF). After thermal activation, NUC-107a characterizes the merits of unsaturated In3+ sites, free pyridine moieties, solvent-free nanochannels (10.2 × 15.7 Å2). Adsorption tests prove that the host framework of NUC-107a has a higher CO2 adsorption (113.2 cm3/g at 273K and 64.8 cm3/g at 298K) than NUC-66 (91.2 cm3/g at 273K and 53.0 cm3/g at 298K). Catalytic experiments confirmed that activated NUC-107a with the aid of n-Bu4NBr was capable of efficiently catalyzing the cycloaddition of CO2 with epoxides into corresponding cyclic carbonates under the mild conditions. Under the similar conditions of 0.10mol% MOFs, 0.5mol% n-Bu4NBr, 0.5 MP CO2, 60°C and 3h, compared with NUC-66a, the conversion of SO to SC catalyzed by NUC-107a increased by 21%. Hence, this work offers a valuable perspective that the in situ creation of robust defect-engineered MOFs can be realized by regulating the growth environment.

Assembly of zeolite-like anionic indium-organic frameworks based on flexible tetra-carboxylate ligands for organic dyes separation

Zeolite-like metal-organic frameworks (ZMOFs) have attracted a great attention because of their special performances in adsorption and separation. It is still of significant to synthesize new ZMOFs with attractive structural features. In this work, two new anionic MOFs, namely [(Me2)NH2]·[In(TCM)]·4DMF (JOU-13), and [(Me2)NH2]·[In(TCM)]·DMF (JOU-14), have been successfully synthesized based on [In(COO)4]- units and flexible tetra-carboxylate ligand (H4TCM = Tetrakis(4-carboxyphenoxymethyl)methane). The structures of JOU-13 and JOU-14 were well characterized by single-crystal X-ray diffraction. It is shown that JOU-13 represents a rare example of interpenetrating framework with gis topology, while JOU-14 is a (4,4)-connected dia topological structure. Notably, JOU-13, owning to its porous and anionic skeleton, exhibits outstanding performance in selectively adsorbing and separating cationic dye methylene blue, displaying reversible capabilities in dye adsorption and release. This work provides valuable clues for preparing new anionic zeolite-like MOFs with special properties.

Multifunctional In-MOF and Its S-Scheme Heterojunction toward Pollutant Decontamination via Fluorescence Detection, Physical Adsorption, and Photocatalytic REDOX.

A novel doubly interpenetrated indium-organic framework of 1 has been assembled by In3+ ions and highly conjugated biquinoline carboxylate-based bitopic connectors (H2L). The isolated 1 exhibits an anionic framework possessing channel-type apertures repleted with exposed quinoline N atoms and carboxyl O atoms. Owing to the unique architecture, 1 displays a durable photoluminescence effect and fluorescence quenching sensing toward CrO42-, Cr2O72-, and Cu2+ ions with reliable selectivity and anti-interference properties, fairly high detection sensitivity, and rather low detection limits. Ligand-to-ligand charge transition (LLCT) was identified as the essential cause of luminescence by modeling the ground state and excited states of 1 using DFT and TD-DFT. In addition, the negatively charged framework has the ability to rapidly capture single cationic MB, BR14, or BY24 and their mixture, including the talent to trap MB from the (MB + MO) system with high selectivity. Moreover, intrinsic light absorption capacity and band structure feature endow 1 with effective photocatalytic decomposition ability toward reactive dyes RR2 and RB13 under ultraviolet light. Notably, after further polishing the band structure state of 1 by constructing the S-scheme heterojunction of In2S3/1, highly efficient photocatalytic detoxification of Cr(VI) and degradation of reactive dyes have been fully achieved under visible light. This finding may open a new avenue for designing novel multifunctional MOF-based platforms to address some intractable environmental issues, i.e., detection of heavy metal ions, physical capture of pony-sized dyes, and photochemical decontamination of ultrastubborn reactive dyes and highly toxic Cr(VI) ions from water.

A novel topological indium–organic framework for reversible ammonia uptake under mild conditions and catalysis

An unprecedented trinodal 3,3,4-connected 3D MOF, [In8(μ2-OH)6(μ2-H2O)3L6Cl6]·5DMF·4H2O (L = 2,2′-dimethylbiphenyl-4,4′-dicarboxylate), has been built to show an NH3 uptake of 10.4 mmol g−1 at 273 K with the regeneration temperature of 60 °C.

Erratum to: A robust indium-organic framework with open tubular channels for efficient separation of acetylene

Erratum to: A robust indium-organic framework with open tubular channels for efficient separation of acetylene

A Tb3+ ion encapsulated anionic indium-organic framework as logical probe for distinguishing quenching Fe3+ and Cu2+ ions

We successfully synthesized a stable anionic microporous metal-organic framework (MOF) HDU-1 ([Me2NH2]2In2[(TATAB)4(DMF)4](DMF)4(H2O)4) and constructed a fluorescent probe Tb@HDU-1 by an exchange strategy. Because of its suspension distinct fluorescent response of Tb(III) characteristic transition and ligand emission, the Tb@HDU-1 can be used as fluorescent probe for sensing towards Fe3+ and Cu2+ ions. It is surprising that Tb@HDU-1 is used as a ratiometric fluorescent probe for Cu2+ ions while only single peak detection for Fe3+ ions, which describes a particular rare example of a sensor based on Ln-MOFs to distinguish quenching Fe3+ and Cu2+ ions. Hence we designed a molecular logic gate device for making the distinction of Fe3+ and Cu2+ ions more clearly and appropriately. In addition, the different quenching effect between Fe3+ and Cu2+ ions may be ascribed to the differences of competitive absorption and interaction between frameworks and metal ions.

A robust indium-organic framework with open tubular channels for efficient separation of acetylene

A robust indium-organic framework with open tubular channels for efficient separation of acetylene

An Anionic Porous Indium-Organic Framework with Nitrogen-Rich Linker for Efficient and Selective Removal of Trace Cationic Dyes.

Metal-organic frameworks (MOFs) with porosity and functional adjustability have great potential for the removal of organic dyes in the wastewater. Herein, an anionic porous metal-organic framework (MOFs) [Me2NH2]2In2[(TATAB)4(DMF)4]·(DMF)4(H2O)4 (HDU-1) was synthesized, which is constructed from a [In(OOC)4]- cluster and a nitrogen-rich linker H3TATAB (4,4',4″-s-triazine-1,3,5-triyltri-p-aminobenzoic acid). The negatively charged [In(OOC)4]- cluster and uncoordinated -COOH on the linker result in one unit cell of HDU-1 having 8 negative sites. The zeta potential of -20.8 mV dispersed in pure water also shows that HDU-1 possesses negatively charged surface potential. The high electronegativity, water stability, and porosity of HDU-1 can facilitate the ion-exchange and Coulombic interaction. As expected, the HDU-1 exhibits high selectivity and removal rates towards trace cationic dyes with suitable size, such as methylene blue (MB) (96%), Brilliant green (BG) (99.3%), and Victoria blue B (VB) (93.6%).

Multivariate indium–organic frameworks for highly efficient carbon dioxide capture and electrocatalytic conversion

A series of trinuclear indium–organic frameworks was synthesized and this work demonstrates that bimetallic engineering is a promising strategy for efficient CO2 capture and electrocatalytic CO2 conversion.

Size-Selective Suzuki-Miyaura Coupling Reaction over Ultrafine Pd Nanocatalysts in a Water-Stable Indium-Organic Framework.

Metal nanoparticles stabilized by crystalline metal-organic frameworks (MOFs) are highly promising for green heterogeneous catalysis. In this work, in situ formed ultrafine Pd nanocatalysts with an average size of 3.14 nm have been successfully immobilized into the mesopores or defects of a water-stable indium-based MOF by the double-solvent method and subsequent reduction. Significantly, the obtained Pd@InOF-1 displays an obvious and satisfactory size-selective effect in the Suzuki-Miyaura coupling reaction between arylboronic acids and aryl bromides. On the basis of the synergistic effect, microporous InOF-1 nanorods afford a confined space for improving the selectivity of target products while Pd nanoparticles endow abundant active sites for catalysis. Herein, choosing the smallest size reactant with only one benzene ring gives the highest isolated yield of 90%, and if the size is larger, the yield is obviously reduced or even the target product could not be collected. Looking forward, this demonstrated study not only assembles a well-designed Pd@MOF composite with unique micro-nanostructures but also delivers an impressive option for cross-coupling reaction, which has implications for the further development of MOF hybrids for sustainable applications.

Precise Introduction of Single Vanadium Site into Indium-Organic Framework for CO2 Capture and Photocatalytic Fixation.

The capture and fixation of CO2 under mild conditions is a cost-effective route to reduce greenhouse gases, but it is challenging because of the low conversion and selectivity issues. Metal-organic frameworks (MOFs) are promising in the fields of adsorption and catalysis because of their structural tunability and variability. However, the precise structural design of MOFs is always pursued and elusive. In this work, a metal-mixed MOF (SNNU-97-InV) was designed by precisely introducing single vanadium site into the isostructural In-MOF (SNNU-97-In). The single V sites clearly change the interactions between the MOF framework and CO2 molecules, leading to a 71.3% improvement in the CO2 adsorption capacity. At the same time, the enhanced light absorption enables SNNU-97-InV to efficiently convert CO2 into cyclic carbonates (CCs) with epoxides under illumination. Controlled experiments showed that the promoted performance of SNNU-97-InV may be that the V═O site can more easily combine with CO2 and convert them into an intermediate state under illumination, and the possible mechanism was thus speculated.

Amide-Functionalized In-MOF for Effective Hydrocarbon Separation and CO2 Catalytic Fixation

Energy saving and emission reduction have always been the goal of separation and catalysis pursued in industrial production. Metal-organic frameworks (MOFs) are leading porous crystal materials with unique advantages in these fields. Based on an amide-modified ligand 5-(ethyl oxamate)-isophthalic acid (H2EtL), a new porous indium-organic framework (Me2NH2)1.5[In1.5L2]·2DMF·2H2O (1) was synthesized and structurally characterized. The unique porous environment gives it dual functional advantages in separation and catalysis. At room temperature, 1 possesses excellent adsorption capacities for C2 hydrocarbons and CO2, showing good separation behaviors for C2 hydrocarbons/CO2 on CH4 and C2H2 on CO2, which is conducive to efficient purification of CH4 and C2H2 confirmed by the breakthrough experiment. Meanwhile, catalytic results indicate that 1 can be used as a good catalyst for effective fixation of CO2 under mild conditions to form cyclic carbonates.

Interpenetrating dye-functionalized indium–organic frameworks for photooxidative cyanation and oxidative cyclization

By virtue of light harvesting ability, the O2˙−generation rate and framework stability of indium–organic frameworks can be precisely regulated by the interpenetrated frameworks making them versatile photocatalysts for photooxidative transformation.

Assembly of a rod indium–organic framework with fluorescence properties for selective sensing of Cu2+, Fe3+ and nitroaromatics in water

A chiral fluorescent In-MOF with two types of unique homochiral In–O–In helical chains was synthesized. Then it was developed as a highly sensitive fluorescence sensor for detecting Cu2+, Fe3+ and nitroaromatics in water.

Efficient Cycloaddition of CO2 and Aziridines Activated by a Quadruple-Interpenetrated Indium-Organic Framework as a Recyclable Catalyst.

On the basis of the global warming effect, it is of great significance to convert CO2 into the high value-added products oxazolidinones, but investigations on main-group-based metal-organic frameworks (MOFs) as heterogeneous catalysts still have not been reported so far. In this work, a quadruple-interpenetrated porous indium-based MOF, {[NH2(CH3)2][In(CPT)2]·3CH3CN·3DMA}n (1), is constructed from the organic ligand 3,5-bis(4'-carboxyphenyl)-1,2,4-triazole through solvothermal reactions, and N2 adsorption proves that the framework has a high Brunauer-Emmett-Teller surface areas with 2024 m2/g. The catalytic research on CO2 conversion reveals that compound 1 has high reactivity for the cycloaddition of CO2 with aziridines, and the product 3-ethyl-5-phenyloxazolidin-2-one can be obtained with a yield of 99% under mild conditions. In addition, 1 exhibits excellent activity for different kinds of substrates and can be reused at least five cycles without any significant deactivation, suggesting that 1 is a potential candidate for the chemical conversion of CO2 and aziridines. Mechanistic explorations indicate that the high efficiency of 1 is attributed to the indium center in the framework as a Lewis acid site, and the large porosity can enrich substrates. Importantly, 1 behaved as the first main-group MOF-based catalyst in the reported coupling reaction of CO2 with aziridines.

Efficient Electroconversion of Carbon Dioxide to Formate by a Reconstructed Amino-Functionalized Indium-Organic Framework Electrocatalyst.

We report an amino-functionalized indium-organic framework for efficient CO2 reduction to formate. The immobilized amino groups strengthen the absorption and activation of CO2 and stabilize the active intermediates, which endow an enhanced catalytic conversion to formate despite the inevitable reduction and reconstruction of the functionalized indium-based catalyst during electrocatalysis. The reconstructed amino-functionalized indium-based catalyst demonstrates a high Faradaic efficiency of 94.4 % and a partial current density of 108 mA cm-2 at -1.1 V vs. RHE in a liquid-phase flow cell, and also delivers an enhanced current density of ca. 800 mA cm-2 at 3.4 V for the formate production in a gas-phase flow cell configuration. This work not only provides a molecular functionalization and assembling concept of hybrid electrocatalysts but also offers valuable understandings in electrocatalyst evolution and reactor optimization for CO2 electrocatalysis and beyond.

Efficient Electroconversion of Carbon Dioxide to Formate by a Reconstructed Amino‐Functionalized Indium–Organic Framework Electrocatalyst

AbstractWe report an amino‐functionalized indium‐organic framework for efficient CO2 reduction to formate. The immobilized amino groups strengthen the absorption and activation of CO2 and stabilize the active intermediates, which endow an enhanced catalytic conversion to formate despite the inevitable reduction and reconstruction of the functionalized indium‐based catalyst during electrocatalysis. The reconstructed amino‐functionalized indium‐based catalyst demonstrates a high Faradaic efficiency of 94.4 % and a partial current density of 108 mA cm−2 at −1.1 V vs. RHE in a liquid‐phase flow cell, and also delivers an enhanced current density of ca. 800 mA cm−2 at 3.4 V for the formate production in a gas‐phase flow cell configuration. This work not only provides a molecular functionalization and assembling concept of hybrid electrocatalysts but also offers valuable understandings in electrocatalyst evolution and reactor optimization for CO2 electrocatalysis and beyond.

Efficient Gas and VOC Separation and Pesticide Detection in a Highly Stable Interpenetrated Indium-Organic Framework.

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.

Indium-Organic Framework with soc Topology as a Versatile Catalyst for Highly Efficient One-Pot Strecker Synthesis of α-aminonitriles.

An In(III) based metal-organic framework (MOF), In-pbpta, with soc topology was constructed from the trigonal prismatic [In3(μ3-O)(H2O)3(O2C-)6] secondary building unit (SBU) and a custom-designed tetratopic linker H4pbpta (pbpta = 4,4',4″,4‴-(1,4-phenylenbis(pyridine-4,2,6-triyl))-tetrabenzoic acid)). The obtained MOF shows a Brunauer-Emmett-Teller surface area of 1341 m2/g with a pore volume of 0.64 cm3/g, which is the highest among the scarcely reported In-soc-MOFs. The constructed MOF demonstrates excellent performance as a heterogeneous Lewis acid catalyst for highly efficient conversion in a one-pot multicomponent Strecker reaction for the preparation of α-aminonitriles under solvent-free conditions, which can be easy to separate and recycle without significant loss of activity for up to seven cycles. The computational modeling studies suggest the presence of the three substrates in close vicinity to the In-oxo cluster. The strong interactions of the aldehyde/ketone and the amine with the In-oxo cluster together with the readily available cyanide ion around the In-oxo cluster lead to high catalytic conversion within a short period of time for the MOF catalyst. Our work therefore lays a foundation to develop MOF as a new class of efficient heterogeneous catalyst for one-pot Strecker reaction.

Indium-organic framework CPP-3(In) derived Ag/In2O3 porous hexagonal tubes for H2S detection at low temperature

There is a great demand for high-performance hydrogen sulfide (H2S) sensors with low operating temperatures. Ag/In2O3 hexagonal tubes with different proportions were prepared by the calcination of Ag+-impregnated indium-organic frameworks (CPP-3(In)), and the developed sensors exhibit enhanced gas-sensing performance toward H2S. Gas sensing measurements indicate that the response of Ag/In2O3 (2.5 wt%) sensor to 5 ppm H2S has the highest response (119), operated at 70 °C. The Ag/In2O3 (2.5 wt%) based sensor exhibits short response time (20 s), low detection limit (300 ppb), and good selectivity toward H2S gas, which imply that the CPP-3(In)-derived Ag/In2O3 hexagonal tube is a promising candidate to be constructed a low power-consumption H2S sensor.