A Multifunctional Tb-MOF for Highly Discriminative Sensing of Eu3+ /Dy3+ and as a Catalyst Support of Ag Nanoparticles

Multifunctional and Ultrastable Co-MOF Effectively Separates Various Different Component Gas Mixtures

Developing low-cost and multifunctional adsorbents for adsorption separation to obtain high-purity (>99.9%) gases is intriguing yet challenging. Notably, the ongoing trade-off between adsorption capacity and selectivity in separating multicomponent mixed gases still persists as a pressing scientific challenge requiring urgent attention. Herein, the ultrastable TJT-100 exhibits unique structural characteristics including uncoordinated carboxylate oxygen atoms, coordinated water molecules directed toward the pore surface, and sufficient Me2NH2+ cations in channels. TJT-100 exhibits a high adsorption capacity and exceptional separation performance, particularly notable for its high C2H2 capacity of 127.7 cm3/g and remarkable C2H2 selectivity over CO2 (5.4) and CH4 (19.8), which makes it a standout material for various separation applications. In a breakthrough experiment with a C2H2/CO2 mixture (v/v = 50/50), TJT-100 achieved a record-high C2H2 productivity of 69.33 L/kg with a purity of 99.9%. Additionally, TJT-100 demonstrates its effectiveness in separating CO2 from natural gas and flue gas. Its exceptional selectivity for CO2/CH4 (10.7) and CO2/N2 (11.9) results in a high CO2 productivity of 21.23 and 22.93 L/kg with 99.9% purity from CO2/CH4 (v/v = 50/50) and CO2/N2 (v/v = 15/85) mixtures, respectively.

Recent Advances in Pristine Iron Triad Metal-Organic Framework Cathodes for Alkali Metal-Ion Batteries

Pristine iron triad metal-organic frameworks (MOFs), i.e., Fe-MOFs, Co-MOFs, Ni-MOFs, and heterometallic iron triad MOFs, are utilized as versatile and promising cathodes for alkali metal-ion batteries, owing to their distinctive structure characteristics, including modifiable and designable composition, multi-electron redox-active sites, exceptional porosity, and stable construction facilitating rapid ion diffusion. Notably, pristine iron triad MOFs cathodes have recently achieved significant milestones in electrochemical energy storage due to their exceptional electrochemical properties. Here, the recent advances in pristine iron triad MOFs cathodes for alkali metal-ion batteries are summarized. The redox reaction mechanisms and essential strategies to boost the electrochemical behaviors in associated electrochemical energy storage devices are also explored. Furthermore, insights into the future prospects related to pristine iron triad MOFs cathodes for lithium-ion, sodium-ion, and potassium-ion batteries are also delivered.

Turn-off luminescence sensing, white light emission and magnetic studies of two-dimensional lanthanide MOFs

The lanthanide metal organic framework compounds [Ln(BPTA)1.5(Bpy)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1a-5a) and [Ln(BPTA)1.5(Phen)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1b-5b) were prepared by employing 2,5-bis(prop-2-yn-1-yloxy)terephthalic acid (2,5-BPTA) as the primary ligand and 2,2'-bipyridine (1a-5a) and 1,10-phenanthroline (1b-5b) as the secondary ligands. Single-crystal structural studies on [Gd(BPTA)1.5(Bpy)]·0.5DMF (3a) and [Dy(BPTA)1.5(Phen)]·0.5DMF (5b) indicated that the compounds have a two-dimensional structure. The Y compound exhibits blue emission, and the other compounds exhibit emission in the expected regions (λex = 350 nm). White light emission was achieved by careful mixing of the red (Eu3+) and green (Tb3+) components in the blue emitting Y compound. Thus, Y0.96Tb0.02Eu0.02 (bpy) and Y0.939Tb0.06Eu0.001 (phen) were found to show white emission when excited using a wavelength of 350 nm. The introduction of N-N-containing ancillary ligands (i.e., bpy and phen) increased the overall quantum yield (QY) of white light emission to 31% and 43%, respectively. The high QY observed for the Tb and Eu compounds was found to be sensitive and selective for the fluorometric detection of azinphos-methyl pesticide and trinitrophenol (TNP) in an aqueous medium at the ppb level. The same behaviour was observed when utilising the compounds as onsite paper strip sensors. Their magnetic properties were also studied, revealing for the Tb and Dy derivatives slow relaxation of the magnetisation at low temperature. The present study highlights the usefulness of rigid π-conjugated molecules such as 2,2'-bipyridine and 1,10-phenanthroline in enhancing the many utilities of rare-earth-containing MOFs towards white light emission, the sensing of harmful and dangerous substances and magnetic properties.

Synergistic luminescence effect and high-pressure optical properties of CsPbBr2Cl@EuMOFs nanocomposites

Metal-organic frameworks (MOFs) are a class of highly porous materials that have garnered significant attention in the field of optoelectronics due to their exceptional properties. In this study, CsPbBr₂Cl@EuMOFs nanocomposites were synthesized using a two-step method. The fluorescence evolution of the CsPbBr₂Cl@EuMOFs was investigated under high pressure, revealing a synergistic luminescence effect between CsPbBr₂Cl and Eu³⁺. The study found that the synergistic luminescence of CsPbBr₂Cl@EuMOFs remains stable even under high pressure, and there is no energy transfer among different luminous centers. These findings provide a meaningful case for future research on nanocomposites with multiple luminescent centers. Additionally, CsPbBr₂Cl@EuMOFs exhibit a sensitive color-changing mechanism under high pressure, making them a promising candidate for pressure calibration via the color change of the MOF materials.

Metal-Organic Framework-Based Colloidal Particle Synthesis, Assembly, and Application

Metal-organic frameworks (MOFs) assembled from metal nodes and organic ligands have received significant attention over the past two decades for their fascinating porous properties and broad applications. Colloidal MOFs (CMOFs) not only inherit the intrinsic properties of MOFs, but can also serve as building blocks for self-assembly to make functional materials. Compared to bulk MOFs, the colloidal size of CMOFs facilitates further manipulation of CMOF particles in a single or collective state in a liquid medium. The resulting crystalline order obtained by self-assembly in position and orientation can effectively improve performance. In this review, we summarize the latest developments of CMOFs in synthesis strategies, self-assembly methods, and related applications. Finally, we discuss future challenges and opportunities of CMOFs in synthesis and assembly, by which we hope that CMOFs can be further developed into new areas for a wider range of applications.

Metal-Organic Frameworks as Intelligent Drug Nanocarriers for Cancer Therapy

Metal-organic frameworks (MOFs) are crystalline porous materials with periodic network structures formed by self-assembly of metal ions and organic ligands. Attributed to their tunable composition and pore size, ultrahigh surface area (1000-7000 m2/g) and pore volume (1.04-4.40 cm3/g), easy surface modification, appropriate physiological stability, etc., MOFs have been widely used in biomedical applications in the last two decades, especially for the delivery of bioactive agents. In the initial stage, MOFs were widely used to load small molecule drugs with ultra-high doses. Whereafter, more recent work has focused on the load of biomacromolecules, such as nucleic acids and proteins. Over the past years, we have devoted extensive effort to investigate the function of MOF materials for bioactive agent delivery. MOFs can be used not only as an intelligent nanocarrier to deliver or protect bioactive agents but also as an activator for their release or activation in response to the different microenvironments. Altogether, this review details the current progress of MOF materials for bioactive agent delivery and looks into their future development.

Dy(III)-coordination imprinted self-assembly microspheres based on a silica core for highly sensitive and selective detection of two carbamate pesticides

Carbamate (CB) pesticides possess potential carcinogenic and mutagenic activities towards humans even at very low dosages. Thus, broad-specificity probes with high sensitivity and speed are needed for multiple CB determination. This study is the first to focus on Dy³⁺ ions-coordinated self-assembly on a silica core using a surface imprinting procedure, for the simultaneous fluorometric detection of residues of metolcarb (MC) and pirimicarb (PC) insecticides. A simple and mild solvothermal method was applied for the preparation of fluorescent imprinted microspheres starting from 1,10-phenanthroline (Phen)-ligated Dy³⁺ ions to guide imprinted self-assembly of chitosan (CTS), glutaraldehyde (GA), and two carbamate pesticides (MC and PC) on the silica surface by means of coordinate bonds and hydrogen bonds. The as-prepared microspheres displayed strong fluorescence emissions via the antenna effect derived from the Phen ligand and the Schiff base oligomers for sensitizing the Dy³⁺ ions. An expanded in-depth mechanism study was performed on the fluorescence enhancement involving Förster resonance energy transfer (FRET) from the pesticides (donor) to the acceptor. A linear increase in fluorescence at 483 nm for MC and 574 nm for PC upon the imprinted microspheres was observed under the same 350 nm excitation wavelength. Moreover, the quantitative recognition process could be carried out simultaneously and tolerate strong distractions both from five other similar carbamate insecticides and from complicated matrices (e.g., an extract of Chrysanthemum morifolium Ramat). The detection limit was 4 ng mL^-1 with a range of 10-60 ng mL^-1 for MC and 0.4 ng mL^-1 with a range of 1-30 ng mL^-1 for PC. Further characterization of the material, including TEM, SEM, XPS, and FTIR, Raman, and fluorescence spectra, verified that the Dy³⁺ ions play a decisive role in promoting imprinted self-assembly around the silica core. Hence, a novel polynuclear Ln-organic imprinted probe having high selectivity, stability, and sensitivity for the detection of two carbamate insecticides is presented in this study.

Surface Charge-Directed Efficient and Selective Catalytic Activities of Porous M@UiO-66 Composites (M = Pt or Ag) for Reduction of Organic Pollutants

Precisely constructed porous composites containing catalytically active nanoparticles can stabilize unstable nanoparticles, thus improving catalytic activity and longevity while preventing agglomeration of active nanoparticles. Herein, we report the confined incorporation of highly active metal nanoparticles within a metal-organic framework support and efficient catalytic performances in the reduction of organic pollutants, such as methylene blue (MB) and 4-nitrophenol (4-NP). UiO-66-based porous composites (M@UiO-66, M = Pt or Ag) containing well-dispersed metal nanoparticles are constructed via the one-step thermal treatment of UiO-66 implanted with metal ions (UiO-66/Mⁿ⁺, Mⁿ⁺ = Pt²⁺ or Ag⁺). The comprehensive features of M@UiO-66s, such as well-dispersed nanocatalysts, well-developed pores, and characteristic surface charges, expedite not only efficient but also selective catalytic activities in the reduction of MB or 4-NP, along with impressive recyclability.

Carbazole-Equipped Metal-Organic Framework for Stability, Photocatalysis, and Fluorescence Detection

The useful yet underutilized backfolded design is invoked here for functionalizing porous solids with the versatile carbazole function. Specifically, we attach carbazole groups as backfolded side arms onto the backbone of a linear dicarboxyl linker molecule. The bulky carbazole side arms point away from the carboxyl links and do not disrupt the Zr-carboxyl framework formation; namely, the resultant MOF solid ZrL1 features the same net as that of the unfunctionalized dicarboxyl linker, also known as the PCN-111 net or UiO-66 net. The ZrL1 structure features only half linker occupancy (about 6 out of the 12 linkers around the Zr₆O₈ cluster being missing) and partially collapses upon activation (acetone exchange and evacuation). Notably, the stability improves after heating in diphenyl oxide at 260 °C (POP-260 treatment; to form ZrL1-260), as indicated by the higher crystallinity and surface area of the activated ZrL1-260 sample. The ZrL1-260 samples achieve 72% yield in photocatalyzing reductive dehalogenation of phenacyl bromide; ZrL1 can detect nitro-aromatic compounds via fluorescence quenching, with selectivity and sensitivity toward 4-nitroaniline, featuring a limit of detection of 96 ppb.

Simultaneous Control of Pore-Space Partition and Charge Distribution in Multi-Modular Metal-Organic Frameworks

We report here a strategy for making anionic pacs type porous materials by combining pore space partition with charge reallocation. The method uses the first negatively charged pore partition ligand (2,5,8-tri-(4-pyridyl)-1,3,4,6,7,9-hexaazaphenalene, H-tph) that simultaneously enables pore partition and charge reallocation. Over two dozen anionic pacs materials have been made to demonstrate their excellent chemical stability and a high degree of tunability. Notably, Ni₃ -bdt-tph (bdt=1,4-benzeneditetrazolate) exhibits month-long water stability, while CoV-bdt-tph sets a new benchmark for C₂ H₂ storage capacity under ambient conditions for ionic MOFs. In addition to tunable in-framework modules, we show feasibility to tune the type and concentration of extra-framework counter cations and their influence on both stability and capability to separate industrial C₃ H₈ /C₃ H₆ and C₆ H₆ /C₆ H₁₂ mixtures.

Synthesis of a Lanthanide Metal-Organic Framework and Its Fluorescent Detection for Phosphate Group-Based Molecules Such as Adenosine Triphosphate

Adenosine triphosphate (ATP) is an important kind of metabolized biological molecule that is formed in organisms, especially in mitochondria, is used universally as energy, and is one of the most significant multifunctional biological molecules. Metal-organic frameworks (MOFs) have been widely used in many applications such as gas storage and separation, drug delivery, heterogeneous catalysis, chemical sensors, etc. Remarkably, lanthanide MOFs (Ln-MOFs), which display large pores, multiple dimensions, and unique lanthanide luminescence properties, are widely used as chemical sensors. A novel three-dimensional probe, Eu2(sbdc)3(H2O)3 (Eu-sbdc), was successfully self-assembled with Eu(NO3)3·6H2O and 5,5-dioxo-5H-dibenzo[b,d]thiophene-3,7-dicarboxylic acid (H2sbdc). The Ln-MOF Eu-sbdc can quickly and effectively optically detect ATP via a luminescent quenching mechanism. The Ksv value of Eu-sbdc is 1.02 × 104 M-1, and the lower detection limit of Eu-sbdc for ATP is 20 μM, which is more sensitive to ATP. Its mechanism of monitoring ATP might be a dynamic or static quenching process. Eu-sbdc could effectively and quickly recognize ATP with high sensitivity.

Multiple fluorescence response behaviors towards antibiotics and bacteria based on a highly stable Cd-MOF

The abuse of antibiotics has triggered the rise of drug-resistance bacteria, which has seriously threatened public health globally. As a result, carrying out efficient and accurate antibiotic and bacteria identification are quite significant but challenge. Herein, an unprecedented Cd-MOF-based sensor, [CdL]_n [1, H₂L = 4-(2-methyl-1H-benzo[d]imidazol-1-yl) isophthalic acid] with multiple fluorescence response behaviours towards antibiotics and bacteria was developed. Single-crystal X-ray diffraction revealed that 1 is a mesomeric 2D bilayer, which is comprised of two opposite chiral mono-layers, each assembled by left-handed or right-handed helixes. More interestingly, 1 represented multiplex detection capability towards antibiotics and bacteria through two detection behaviors: toward nitro-antibiotics and chlortetracycline (CTC) via fluorescent quenching, while toward Staphylococcus albus (S. albus) via fluorescent enhancement. Remarkably, 1 showed a low limit of detection (LOD, 47 CFU/mL) accompanied with specificity in the detection of S. albus compared to other bacteria, such as Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumonia, Pseudomonas aeruginosa and Escherichia coli. In addition, the LOD could reach to ppm level for nitro-antibiotics and CTC. Moreover, the practical application of 1 was further reinforced through the detection of nitro-antibiotics and CTC, as well as S. albus in fetal calf serum and river water.

Quasi-HKUST Prepared via Postsynthetic Defect Engineering for Highly Improved Catalytic Conversion of 4-Nitrophenol

HKUST-1 [Cu₃(BTC)₂(H₂O)₃]_n·nH₂OMeOH was submitted to thermolysis under controlled conditions at temperatures between 100 and 300 °C. This treatment resulted in partial ligand decarboxylation, generating coordinatively unsaturated Cu²⁺ sites with extra porosity on the way to the transformation of the initial HKUST-1 framework to CuO. The obtained materials retaining in part the HKUST-1 original crystal structure (quasi-MOFs) were used to promote 4-nitrophenol conversion to 4-aminophenol. Because of the partial linker decomposition, the quasi-MOF treated at 240 °C contains coordinatively unsaturated Cu²⁺ ions distributed throughout the Q-HKUST lattice together with micro- and mesopores. These defects explain the excellent catalytic performance of QH-240 with an apparent rate constant of 1.02 × 10^-2 s^-1 in excess of NaBH₄ and an activity factor and half-life time of 51 s^-1g^-1 and 68 s, respectively, which is much better than that of the HKUST parent. Also, the induction period decreases from the order of minutes to seconds in the presence of the HKUST and QH-240 catalysts, respectively. Kinetic studies fit with the Langmuir-Hinshelwood theory in which both 4-nitrophenol and BH₄^- should be adsorbed onto the catalyst surface. The values of the true rate constant (k), the adsorption constants of 4-nitrophenol and BH₄^- (K_4-NP and K_BH4^-), as well as the activation energy are in agreement with a rate-determining step involving the reduction of 4-nitrophenol by the surface-bound hydrogen species.

Naphthalene-tagged highly stable and reusable luminescent metal-organic probes for selective and fast detection of 4-nitroaniline in water

In this paper we report the synthesis, characterization, properties and application of four new Zn(II) and Cd(II) based luminescent metal-organic probes, {[Zn(mbhna)(bpea)]}n (1), {[Cd(mbhna)(bpea)]}n (2), {[Zn(mbhna)(bpba)].CH3OH.H2O}n (3) and {[Cd(mbhna)(bpba)]}n (4),...

Investigation on the catalytic behavior of a novel thulium-organic framework with a planar tetranuclear {Tm4} cluster as the active center for chemical CO2 fixation

Herein, the exquisite combination of coplanar [Tm₄(CO₂)₁₀(μ₃-OH)₂(μ₂-HCO₂)(OH₂)₂] clusters ({Tm₄}) and structure-oriented functional BDCP^5- leads to the highly robust nanoporous {Tm₄}-organic framework {(Me₂NH₂)[Tm₄(BDCP)₂(μ₃-OH)₂(μ₂-HCO₂)(H₂O)₂]·7DMF·5H₂O}_n (NUC-37, H₅BDCP = 2,6-bis(2,4-dicarboxylphenyl)-4-(4-carboxylphenyl)pyridine). To the best of our knowledge, NUC-37 is the first anionic {Ln₄}-based three-dimensional framework with embedded hierarchical microporous and nanoporous channels, among which each larger one is shaped by six rows of coplanar {Tm₄} clusters and characterized by plentiful coexisting Lewis acid-base sites on the inner wall including open Tm^III sites, N_pyridine atoms, μ₃-OH and μ₂-HCO₂. Catalytic experimental studies exhibit that NUC-37 possesses highly selective catalytic activity on the cycloaddition of epoxides with CO₂ as well as high recyclability under gentle conditions, which should be ascribed to its nanoscale channels, rich bifunctional active sites, and stable physicochemical properties. This work offers an effective means for synthesizing productive cluster-based Ln-MOF catalysts by employing structure-oriented ligands and controlling the solvothermal reaction conditions.

Silver nanomaterials: synthesis and (electro/photo) catalytic applications

In view of their unique characteristics and properties, silver nanomaterials (Ag NMs) have been used not only in the field of nanomedicine but also for diverse advanced catalytic technologies. In this comprehensive review, light is shed on general synthetic approaches encompassing chemical reduction, sonochemical, microwave, and thermal treatment among the preparative methods for the syntheses of Ag-based NMs and their catalytic applications. Additionally, some of the latest innovative approaches such as continuous flow integrated with MW and other benign approaches have been emphasized that ultimately pave the way for sustainability. Moreover, the potential applications of emerging Ag NMs, including sub nanomaterials and single atoms, in the field of liquid-phase catalysis, photocatalysis, and electrocatalysis as well as a positive role of Ag NMs in catalytic reactions are meticulously summarized. The scientific interest in the synthesis and applications of Ag NMs lies in the integrated benefits of their catalytic activity, selectivity, stability, and recovery. Therefore, the rise and journey of Ag NM-based catalysts will inspire a new generation of chemists to tailor and design robust catalysts that can effectively tackle major environmental challenges and help to replace noble metals in advanced catalytic applications. This overview concludes by providing future perspectives on the research into Ag NMs in the arena of electrocatalysis and photocatalysis.

A base-free Chan–Lam reaction catalyzed by an easily assembled Cu(II)-carboxylate metal-organic framework

A new copper(II) metal-organic framework is constructed as a sustainable copper heterogeneous catalyst. Cu-DPTCA, with high catalytic activity, can effectively promote the Chan–Lam coupling reaction of arylboronic acids and amines without adding any base or additive.

Rare-Earth-Based Metal-Organic Frameworks as Multifunctional Platforms for Catalytic Conversion

The development of catalytic conversion is very important for human society. In the catalytic process, metal-organic frameworks (MOFs) can be utilized to obtain effective catalysts for their porous structures and adjustable properties. In addition, the introduction of rare-earth (RE) elements with unique properties for catalysts can realize good catalytic performances. Thus, the RE-MOF related catalysts for catalytic conversion are summarized. Due to the cooperation of RE elements and porous MOF structures, the RE-based MOFs can be used as promising catalysts or precursors/supports for other catalysts in the areas of energy conversion, environmental governance, and organic synthesis. These aggregated studies highlight the RE-MOFs as promising candidates for catalytic conversion.

Novel Multifunctional Samarium-Organic Framework for Fluorescence Sensing of Ag+, MnO4 -, and Cimetidine and Electrochemical Sensing of o-Nitrophenol in Aqueous Solutions

A novel Sm-metal-organic framework (MOF) sensor with the molecular formula Sm8(HDBA)6·H2O has been prepared based on a penta-carboxyl organic ligand (H5DBA = 3,5-di(2',4'-dicarboxylphenyl)benzoic acid) and samarium nitrate under solvothermal conditions. Sm-MOF is characterized by single-crystal X-ray diffraction analysis, elemental analysis, thermogravimetric analysis, and powder X-ray diffraction analysis. Structural analysis shows that the dimer metal units are alternately connected to form a one-dimensional chain, and this chain is connected by the bridging carboxyl oxygen of the ligand H5DBA to form a two-dimensional double-layer plane, which then expands into a three-dimensional microporous framework. Fluorescence detection studies show that Sm-MOF can detect Ag+ ions, MnO4 - anions, and cimetidine tablets with high sensitivity and selectivity and can also be used to electrochemically detect o-nitrophenol in water. High-sensitivity detection capability of the Sm-MOF can enrich the application of samarium complexes in multifunctional sensors.

A novel high sensitive Cd-MOF fluorescent probe for acetone vapor in air and picric acid in water: Synthesis, structure and sensing properties

A novel three-dimensional luminescence Cd-MOF sensor with the molecular formula {[(CH₃)₂NH₂]₂ Cd₃(ptptc)₂} (complex 1) has been synthesized by using terphenyl-3,3',5,5'-tetracarboxylic acid (H₄ptptc) and Cd(NO₃)₂·4H₂O under solvothermal conditions. Single crystal X-ray diffraction analysis shows that complex 1 crystallizes in the monoclinic system C2/c space group and consists of one-dimensional channels. Complex 1 exhibits characteristic fluorescence emission (λ_em = 380 nm) both in solid state and solvents upon excitation at 300 nm. Real-time fluorescence quenching of complex 1 was observed in the fluorescence sensing of acetone vapor and picric acid. Intriguingly, ppm scale detection limit for acetone vapor in air and nano-mole scale detection limit for picric acid in water were observed. Moreover, good reusability and liner/nonlinear relationships were observed in the fluorescent titration.

Synthesis of Three Dimensional Cs-γ-CD-MOFs and the Adsorption of Myricetin

A new Cs-γ-CD-MOF material obtained in colourless large crystals and with a three-dimensional porous structure containing coordinated by cesium ions and γ-cyclodextrin was synthesised by an improved vapour diffusion method. The chemical formula of the Cs-γ-CD-MOF material was C24H34CsO20, with the I4 space group. Compared with the traditional solvent vapour diffusion method (7 days), this method is advantageous for rapid crystal formation (1 day). Simultaneously, the drug adsortion capacity of γ-CD and Cs-γ-CD-MOFs for myricetin was compared and the results indicated that Cs-γ-CD-MOFs (280.05 mg g−1) have a higher drug adsorption capacity than γ-CD (142.92 mg g−1). Finally, the energy and conformation of the Cs-γ-CD-MOF material for adsorbing the drug myricetin were obtained through molecular docking.

Recent progress in lanthanide metal–organic frameworks and their derivatives in catalytic applications

Research progress in lanthanide metal–organic frameworks and their derivatives in the field of catalysis has been presented on the basis of different organic reactions.

A Multifunctional Tb-MOF Detector for H2O2, Fe3+, Cr2O7 2-, and TPA Explosive Featuring Coexistence of Binuclear and Tetranuclear Clusters

A novel three-dimensional microporous terbium(III) metal-organic framework (Tb-MOF) named as [Tb10 (DBA)6(OH)4(H2O)5]·(H3O)4 (1), was successfully obtained by a solvothermal method based on terbium nitrate and 5-di(2',4'-dicarboxylphenyl) benzoic acid (H5DBA). The Tb-MOF has been characterized by single crystal X-ray diffraction, elemental analysis, thermogravimetry, and fluorescence properties, and the purity was further confirmed by powder X-ray diffraction (PXRD) analysis. Structural analysis shows that there are two kinds of metal cluster species: binuclear and tetranuclear, which are linked by H5DBA ligands in two μ7 high coordination fashions into a three-dimensional microporous framework. Fluorescence studies show that the Tb-MOF can detect H2O2, Fe3+, and Cr2O7 2- with high sensitivity and selectivity and can also be used for electrochemical detection of exposed 2,4,6-trinitrophenylamine (TPA) in water. The highly selective and sensitive detection ability of the Tb-MOF might make it a potential multifunctional sensor in the future.