Highly Stable Zr(IV)-Based Metal-Organic Frameworks for the Detection and Removal of Antibiotics and Organic Explosives in Water

Microencapsulated sunblock nanoparticles based on zeolitic imidazole frameworks for safe and effective UV protection

Microencapsulation of UV filters into ZIFs could improve UV photoprotection and minimize the deleterious effects of UV filter transdermal absorption.

Structure, color-tunable luminescence, and UV-vis/NIR benzaldehyde detection of lanthanide coordination polymers based on two fluorinated ligands

A series of 1D lanthanide coordination polymers exhibits white-light emission and detects benzaldehyde in the UV-visible and NIR region.

Four new metal–organic frameworks based on diverse secondary building units: sensing and magnetic properties

Four new metal–organic frameworks based on diverse secondary building units were assembled and 1 showed high selectivity in the detection of CrO₄²⁻, Cr₂O₇²⁻, MnO₄⁻ and Fe³⁺.

Highly selective luminescence sensing for the detection of nitrobenzene and Fe3+ by new Cd(ii)-based MOFs

Herein, three Cd(ii)-based MOFs were assembled, and the complex 3 showed a high selectivity in the detection of nitrobenzene and Fe³⁺.

Two azo-functionalized luminescent 3D Cd(ii) MOFs for highly selective detection of Fe3+ and Al3+

Two 3D luminescent Cd(ii) MOFs (Cd-MOF-1 and Cd-MOF-2) exposing azo functional sites displayed selective detection of Fe³⁺ and Al³⁺ metal ions with high sensitivities.

Nanoscale zeolitic imidazole framework-90: selective, sensitive and dual-excitation ratiometric fluorescent detection of hazardous Cr(vi) anions in aqueous media

Toxic Cr(vi) anions sensing in aqueous solution has been achieved by virtue of fluorescent nanoscale ZIF-90 and RhB@ZIF-90.

An unprecedented water stable acylamide-functionalized metal–organic framework for highly efficient CH4/CO2 gas storage/separation and acid–base cooperative catalytic activity

HNUST-8 exhibits water stable, efficient CH₄/CO₂ storage and separation, acid–base cooperative catalytic activity in a tandem deacetalization Knoevenagel densation.

Two interpenetrated metal–organic frameworks with a slim ethynyl-based ligand: designed for selective gas adsorption and structural tuning

Structural tuning and selective gas adsorption of two interpenetrated metal–organic frameworks using a slim ethynyl-based ligand were achieved.

Structural diversity of six metal–organic frameworks from a rigid bisimidazole ligand and their adsorption of organic dyes

Six entangled coordination polymers from a bisimidazole ligand and versatile carboxylate acids have been synthesized and structurally characterized. Their adsorption behaviors to organic dyes have also been evaluated.

An efficient strategy for improving the luminescent sensing performance of a terbium(iii) metal–organic framework towards multiple substances

A new luminescent Ln-MOF-based sensor with hydrolytic stability has been successfully prepared.

Seven luminescent metal–organic frameworks constructed from 5-(triazol-1-yl)nicotinic acid: luminescent sensors for CrVI and MnO4− ions in an aqueous medium

Seven new luminescent metal–organic frameworks were assembled and complex 2 shows high selectivity and sensitivity for CrO₄²⁻, Cr₂O₇²⁻ and MnO₄⁻ ions with low detection limits.

Engineering design toward exploring the functional group substitution in 1D channels of Zn–organic frameworks upon nitro explosives and antibiotics detection

Three MOFs (1, 2, 3) with distinct functional groups were prepared. 2 exhibited moderate sensitivity for the detection of specific explosives/antibiotics at the same concentration, which was lower and higher than that of 3 and 1, respectively.

Covalent switching, involving divinylbenzene ligands within 3D coordination polymers, indicated by changes in fluorescence

Reversible single-crystal-to-single-crystal transformations of two photo-responsive three-dimensional coordination polymers exhibit green/blue and green/blue-green fluorescence switching behaviors.

Fluorescent sensors based on AIEgen-functionalised mesoporous silica nanoparticles for the detection of explosives and antibiotics

AIEgen-functionalised mesoporous silica nanoparticles can be used for the detection of explosives and antibiotics based on a FRET mechanism.

Two MOFs as dual-responsive photoluminescence sensors for metal and inorganic ion detection

Two MOFs were synthesized and explored as dual-responsive photoluminescent sensors: 1 for Fe³⁺ and Cr₂O₇²⁻ ions, and 2 for Hg²⁺ and Cr₂O₇²⁻ ions.

Photonic functional metal–organic frameworks

The recent progress in photonic MOFs for luminescence sensing, white-light emission, photocatalysis, nonlinear optics, lasing devices, and biomedicine is summarized.

Improving the capability of UiO-66 for Cr(vi) adsorption from aqueous solutions by introducing isonicotinate N-oxide as the functional group

In this study, we showed that a conceptual design can be helpful in synthesizing environmentally safe and stable adsorbents along with suitable adsorption parameters.

Improved ATR-FTIR detection of hydrocarbons in water with semi-crystalline polyolefin coatings on ATR elements

In situ detection of hydrocarbons in water using ATR-FTIR with LLDPE film.

A 2D porous pentiptycene-based MOF for efficient detection of Ba2+ and selective adsorption of dyes from water

The 2D MOF (UPC-28) as the water monitor can exhibit efficient detection of Ba²⁺ and perform selective adsorption of dyes from water.

Construction of metal–organic frameworks (MOFs) and highly luminescent Eu(iii)-MOF for the detection of inorganic ions and antibiotics in aqueous medium

A series of Ln(iii) complexes were synthesized. The highly luminescent chemically stable Eu-MOF shows multi-responsive luminescence sensing functions.

A bi-metallic MOF catalyst via sensitive detection & adsorption of Fe3+ ions for size-selective reaction prompting

Novel MOF adsorbed Fe³⁺ presents the first example of a bi-metallic Lewis-acid catalyst for the cyanosilylation reaction in a size-selective fashion.

Fluorescent zinc(ii)-based metal–organic frameworks for nitroaromatics sensing

A new structural metal–organic framework with fluorescence properties was synthesized and applied for sensitive and selective sensing of nitroaromatics.

A water-stable Tb(iii)-based metal–organic gel (MOG) for detection of antibiotics and explosives

A luminescent Tb-based metal organic gel was prepared by in situ metal node metathesis and it exhibited sensitive detection ability effectively towards antibiotics and explosives in water.

Highly selective and sensitive detection of Hg2+, Cr2O72−, and nitrobenzene/2,4-dinitrophenol in water via two fluorescent Cd-CPs

Taking advantage of fluorescent Cd-CPs with 3,3′-thiodipropionic acid and imidazole ligands, herein, we demonstrate the synthesis of functional CPs, and develop two Cd-CP fluorescence sensing materials with highly selective and sensitive detection of Hg²⁺, Cr₂O₇²⁻, NB,/2,4-DNP in water.

Fast and scalable synthesis of uniform zirconium-, hafnium-based metal-organic framework nanocrystals

Metal-organic frameworks based on zirconium or hafnium possess tantalizing commercial prospects due to their high stability but require a long reaction time to form crystals. The fast synthesis of uniform Zr-, Hf-MOF nanocrystals at scale is of key importance in the potential commercial application of MOFs. In this work, we have developed a versatile strategy through controlling the hydrolysis and nucleation of metal salts in the presence of acetic acid and water; up to 24 grams of UiO-66-NH₂ nanocrystals with a uniform octahedron could be synthesized within 15 minutes using a one step method. The current synthetic strategy could be extended to other Zr-, Hf-MOF nanocrystals [UiO-66-Fast, UiO-66-(OH)₂-Fast, UiO-66-2,6-NDC-Fast, UiO-67-Fast, BUT-12-Fast, PCN-222-Ni-Fast, PCN-222-Co-Fast, Hf-UiO-66-Fast, Hf-UiO-66-NH₂-Fast, Hf-UiO-66-(OH)₂-Fast, Hf-UiO-66-2,6-NDC-Fast and Hf-BUT-12-Fast]. Significantly, when noble metal nanoparticles (NPs) are introduced into MOF precursors, NPs encapsulated in MOFs with excellent dispersion have also been obtained and show outstanding performance in catalysis. This facile procedure is expected to pave the way to expand the commercial applications of MOFs.

Efficient Ultraviolet Light Detector Based on a Crystalline Viologen-Based Metal-Organic Framework with Rapid Visible Color Change under Irradiation

A convenient colorimetric molecular system constructed by the zinc viologen-carboxylate framework is developed for naked eye detection of instantaneous UV exposure levels. Only narrow-band absorption in UV regions and a unique interpenetrated structure of its colorless crystal enable the system to give a fast response toward UV irradiance with intensity as low as 0.001 mw/cm².

Carbon dioxide capture and conversion by an acid-base resistant metal-organic framework

Considering the rapid increase of CO₂ emission, especially from power plants, there is a constant need for materials which can effectively eliminate post-combustion CO₂ (the main component: CO₂/N₂ = 15/85). Here, we show the design and synthesis of a Cu(II) metal-organic framework (FJI-H14) with a high density of active sites, which displays unusual acid and base stability and high volumetric uptake (171 cm³ cm⁻³) of CO₂ under ambient conditions (298 K, 1 atm), making it a potential adsorbing agent for post-combustion CO₂. Moreover, CO₂ from simulated post-combustion flue gas can be smoothly converted into corresponding cyclic carbonates by the FJI-H14 catalyst. Such high CO₂ adsorption capacity and moderate catalytic activity may result from the synergistic effect of multiple active sites.

Increasing CO₂ emissions pose serious environmental issues. Here, the authors report the synthesis of a robust metal-organic framework which displays high volumetric uptake of post-combustion CO₂ under ambient conditions and can catalyze CO₂ fixation into cyclic carbonates.

A new two-dimensional CdII coordination polymer based on 2-(1H-imidazol-1-ylmethyl)-6-methyl-1H-benzimidazole and benzene-1,2-dicarboxylate: synthesis, crystal structure and characterization

In the construction of coordination polymers, many factors can influence the formation of the final architectures, such as the nature of the metal centres, the organic ligands and the counter-anions. In the coordination polymer poly[aqua(μ-benzene-1,2-dicarboxylato-κ⁴O¹,O^1':O²,O^2')[μ-2-(1H-imidazol-1-ylmethyl)-6-methyl-1H-benzimidazole-κ²N²:N³]cadmium(II)], [Cd(C₁₂H₁₂N₄)(C₈H₄O₄)(H₂O)]_n or [Cd(immb)(1,2-bdic)(H₂O)]_n, each Cd^II ion is seven-coordinated by two N atoms from two symmetry-related 2-(1H-imidazol-1-ylmethyl)-6-methyl-1H-benzimidazole (immb) ligands, by four O atoms from two symmetry-related benzene-1,2-dicarboxylate (1,2-bdic^2-) ligands and by one water molecule, leading to a CdN₂O₅ distorted pentagonal bipyramidal coordination environment. The immb and 1,2-bdic^2- ligands bridge Cd^II ions and form a two-dimensional network structure. O-H...O and N-H...O hydrogen bonds stabilize the structure. In addition, the IR spectroscopic properties, PXRD patterns, thermogravimetric behaviour and fluorescence properties of the title polymer have been investigated.

Explosives in the Cage: Metal-Organic Frameworks for High-Energy Materials Sensing and Desensitization

An overview of the current status of coordination polymers and metal-organic frameworks (MOFs) pertaining to the field of energetic materials is provided. The explosive applications of MOFs are discussed from two aspects: one for detection of explosives, and the other for explosive desensitization. By virtue of their adjustable pore/cage sizes, high surface area, tunable functional sites, and rich host-guest chemistry, MOFs have emerged as promising candidates for both explosive sensing and desensitization. The challenges and perspectives in these two areas are thoroughly discussed, and the processing methods for practical applications are also discussed briefly.

A Copper(II)-Paddlewheel Metal-Organic Framework with Exceptional Hydrolytic Stability and Selective Adsorption and Detection Ability of Aniline in Water

Copper(II)-paddlewheel-based metal-organic frameworks (CP-MOFs) represent a unique subclass of MOFs with highly predictable porous structures, facile syntheses, and functional open metal sites. However, the lack of high hydrolytic stability is an obstacle for CP-MOFs in many practical applications. In this work, we report a new CP-MOF, [Cu₄(tdhb)] (BUT-155), which is constructed from a judiciously designed carboxylate ligand with high coordination connectivity (octatopic), abundant hydrophobic substituents (six methyl groups), and substituent constrained geometry (tetrahedral backbone), tdhb^8- [H₈tdhb = 3,3',5,5'-tetrakis(3,5-dicarboxyphenyl)-2,2',4,4',6,6'-hexamethylbiphenyl)]. BUT-155 shows high porosity with a Brunauer-Emmett-Teller surface area of 2070 m²/g. Quite interestingly, this CP-MOF retains its structural integrity after being treated in water for 10 days at room temperature or in boiling water for 24 h. To the best of our knowledge, BUT-155 represents the first CP-MOF that is demonstrated to retain its structural integrity in boiling water. The high hydrolytic stability of BUT-155 allowed us to carry out adsorption studies of water vapor and aqueous organic pollutants on it. Water-vapor adsorption reveals a sigmoidal isotherm and a high uptake (46.7 wt %), which is highly reversible and regenerable. In addition, because of the availability of soft-acid-type open Cu(II) sites, BUT-155 shows a high performance for selective adsorption of soft-base-type aniline over water or phenol, and a naked-eye detectable color change for the MOF sample accompanies this. The adsorption selectivity and high adsorption capacity of aniline in BUT-155 are also well-interpreted by single-crystal structures of the water- and aniline-included phases of BUT-155.

Ultrahigh adsorption and singlet-oxygen mediated degradation for efficient synergetic removal of bisphenol A by a stable zirconium-porphyrin metal-organic framework

Bisphenol A (BPA), one of 23 most important endocrine disrupting chemicals, was efficiently removed and sequentially photodegraded by a zirconium-porphyrin metal–organic framework (MOF) catalyst under visible light for water treatment. Well control of photodegradation allows the kinetic separation of adsorption step and photodegradation step. Ultrahigh adsorption uptake of 487.69 ± 8.37 mg g⁻¹ is observed, while efficient photodegradation could be observed within 20 min at the rate of 0.004 mg min⁻¹. The synergetic effect boosts the photocatalytic efficiency and confirms that the catalysis happens inside the MOF pores other than in the solution phase. Furthermore, the mechanism was elucidated by diverse control experiments, such as in the conditions of ¹O₂ scavenger, in darkness and with the changes of light sensitizing ligands. It confirmed that BPA was oxidized by the ¹O₂ which was generated from porphyrin ligand within MOFs under visible-light. The excellent reusability and wide range of suitable pH range make the Zr-porphyrin MOFs practical for the photocatalytic water treatment processes.

Co-ligand tuned pyrimidine-2-carboxylate Mn(ii) complexes from a 2D 63 layer to an interpenetrated srs-net

A 6³ 2D layer complex [Mn₃Cl₃(L₃)]_n·H₂O (1) (L = pyrimidine-2-carboxylate) was obtained by assembling 2-cyanopyrimidine and manganese chloride, in which the L ligands were generated in situ. In 1 six-membered Mn rings were constructed from Mn^II ions and L ligands, which were connected to each other by double chloride anions affording a 2D layer. When the chloride anions in 1 were substituted partly by formate, [Mn₄Cl₃L₄(HCO₂)]_n (2) was obtained. In 2, the L ligands bridge Mn^II to give a 1D chain, which was further connected by the double chloride anions and Cl/formate bridges to form a two-fold interpenetrated srs-net. Interestingly, 2 exhibits an obvious SHG response of approximately 0.8 times that of KDP. Furthermore, 2 is an antiferromagnet with a field induced spin flop transition.

Ultrafast water sensing and thermal imaging by a metal-organic framework with switchable luminescence

A convenient, fast and selective water analysis method is highly desirable in industrial and detection processes. Here a robust microporous Zn-MOF (metal-organic framework, Zn(hpi2cf)(DMF)(H2O)) is assembled from a dual-emissive H2hpi2cf (5-(2-(5-fluoro-2-hydroxyphenyl)-4,5-bis(4-fluorophenyl)-1H-imidazol-1-yl)isophthalic acid) ligand that exhibits characteristic excited state intramolecular proton transfer (ESIPT). This Zn-MOF contains amphipathic micropores (<3 Å) and undergoes extremely facile single-crystal-to-single-crystal transformation driven by reversible removal/uptake of coordinating water molecules simply stimulated by dry gas blowing or gentle heating at 70 °C, manifesting an excellent example of dynamic reversible coordination behaviour. The interconversion between the hydrated and dehydrated phases can turn the ligand ESIPT process on or off, resulting in sensitive two-colour photoluminescence switching over cycles. Therefore, this Zn-MOF represents an excellent PL water-sensing material, showing a fast (on the order of seconds) and highly selective response to water on a molecular level. Furthermore, paper or in situ grown ZnO-based sensing films have been fabricated and applied in humidity sensing (RH<1%), detection of traces of water (<0.05% v/v) in various organic solvents, thermal imaging and as a thermometer.