The development of MOFs-based nanomaterials in heterogeneous organocatalysis

Nitrogen Vacancy Modulation of Tungsten Nitride Peroxidase-Mimetic Activity for Bacterial Infection Therapy

Bacterial infections claim millions of lives every year, with the escalating menace of microbial antibiotic resistance compounding this global crisis. Nanozymes, poised as prospective substitutes for antibiotics, present a significant frontier in antibacterial therapy, yet their precise enzymatic origins remain elusive. With the continuous development of nanozymes, the applications of elemental N-modulated nanozymes have spanned multiple fields, including sensing and detection, infection therapy, cancer treatment, and pollutant degradation. The introduction of nitrogen into nanozymes not only broadens their application range but also holds significant importance for the design of catalysts in biomedical research. The synergistic interplay between W and N induces pivotal alterations in electronic configurations, endowing tungsten nitride (WN) with a peroxidase-like functionality. Furthermore, the introduction of N vacancies augments the nanozyme activity, thus amplifying the catalytic potential of WN nanostructures. Rigorous theoretical modeling and empirical validation corroborate the genesis of the enzyme activity. The meticulously engineered WN nanoflower architecture exhibits an exceptional ability in traversing bacterial surfaces, exerting potent bactericidal effects through direct physical interactions. Additionally, the topological intricacies of these nanostructures facilitate precise targeting of generated radicals on bacterial surfaces, culminating in exceptional bactericidal efficacy against both Gram-negative and Gram-positive bacterial strains along with notable inhibition of bacterial biofilm formation. Importantly, assessments using a skin infection model underscore the proficiency of WN nanoflowers in effectively clearing bacterial infections and fostering wound healing. This pioneering research illuminates the realm of pseudoenzyme activity and bacterial capture-killing strategies, promising a fertile ground for the development of innovative, high-performance artificial peroxidases.

Factors influencing the performance of organocatalysts immobilised on solid supports: A review

Organocatalysis has become a powerful tool in synthetic chemistry, providing a cost-effective alternative to traditional catalytic methods. The immobilisation of organocatalysts offers the potential to increase catalyst reusability and efficiency in organic reactions. This article reviews the key parameters that influence the effectiveness of immobilised organocatalysts, including the type of support, immobilisation techniques and the resulting interactions. In addition, the influence of these factors on catalytic activity, selectivity and recyclability is discussed, providing an insight into optimising the performance of immobilised organocatalysts for practical applications in organic chemistry.

Hierarchical MOFs with Good Catalytic Properties and Structural Stability in Oxygen-Rich and High-Temperature Environments

Metal-organic framework materials are ideal materials characterized by open frameworks, adjustable components, and high catalytic activity. They are extensively utilized for catalysis. Due to decomposition and structural collapse under high temperatures and an oxygen-rich environment, the potential of thermal catalysis is greatly limited. In this research, Co-rich hollow spheres (Co-HSs) with a gradient composition are designed and synthesized to investigate their thermal catalytic properties in the ammonium perchlorate（AP）system. The results demonstrate that Co-HSs@AP exhibits good thermal catalytic activity and a high-temperature decomposition of 292.5 °C, which is 121.6 °C lower than pure AP. The hierarchical structure confers structural stability during the thermal decomposition process. Thermogravimetry-infrared indicates that the inclusion of Co-HSs successfully boosts the level of reactive oxygen species and achieves thorough oxidation of NH3. Based on the above phenomenon, macro dynamics calculations are carried out. The results show that Co-HSs can promote the circulation of lattice oxygen and reactive oxygen species and the multidimensional diffusion of NH3 in an oxygen-rich environment. This material has significant potential for application in the fields of thermal catalysis and ammonia oxidation.

Nanozyme-Enhanced Electrochemical Biosensors: Mechanisms and Applications

Nanozymes, as innovative materials, have demonstrated remarkable potential in the field of electrochemical biosensors. This article provides an overview of the mechanisms and extensive practical applications of nanozymes in electrochemical biosensors. First, the definition and characteristics of nanozymes are introduced, emphasizing their significant role in constructing efficient sensors. Subsequently, several common categories of nanozyme materials are delved into, including metal-based, carbon-based, metal-organic framework, and layered double hydroxide nanostructures, discussing their applications in electrochemical biosensors. Regarding their mechanisms, two key roles of nanozymes are particularly focused in electrochemical biosensors: selective enhancement and signal amplification, which crucially support the enhancement of sensor performance. In terms of practical applications, the widespread use of nanozyme-based electrochemical biosensors are showcased in various domains. From detecting biomolecules, pollutants, nucleic acids, proteins, to cells, providing robust means for high-sensitivity detection. Furthermore, insights into the future development of nanozyme-based electrochemical biosensors is provided, encompassing improvements and optimizations of nanozyme materials, innovative sensor design and integration, and the expansion of application fields through interdisciplinary collaboration. In conclusion, this article systematically presents the mechanisms and applications of nanozymes in electrochemical biosensors, offering valuable references and prospects for research and development in this field.

Eu-MOF based fluorescence probe for ratiometric and visualization detection of Cu2

Water contamination caused by heavy metals represents an urgent global issue. Cu2+, a potential trace heavy metal pollutant, can accumulate in the human body through the food chain, leading to excessive levels that give rise to diverse health complications. Hence, in this investigation, a novel and efficacious fluorescent probe named Eu-BTB was developed for the detection of Cu2+, employing 1,3,5-triphenyl(4-carboxyphenyl) (H3BTB) as the ligand and Eu3+ as the metallic framework. The probe demonstrates exceptional fluorescence characteristics. The interaction between the probe ligand BTB and Eu3+ triggers an antenna effect, heightening the emission efficiency of Eu3+ while preserving its intrinsic emission. The introduction of Cu2+ competes with BTB for binding, thus quelling the antenna effect and inducing a fluorescence alteration. Within the concentration range of 0.05-10 μM, the fluorescence intensity-to-Cu2+ concentration ratio exhibits a robust linear correlation, with a remarkably low detection limit of 10 nM and a rapid response time of 3 min. The fluorescent probe has been effectively deployed for the detection of copper ions in water across diverse environmental conditions, with the obtained outcomes being validated via the conventional approach of inductively coupled plasma mass spectrometry (ICP-MS). The Eu-BTB probe showcases the advantages of simplicity, swiftness, and broad applicability, thus affirming its potential for the prompt and accurate detection of Cu2+ in diverse environmental water samples.

Recent development of organic-inorganic hybrid photocatalysts for biomass conversion into hydrogen production

Over the last few years, photocatalysis using solar radiation has been explored extensively to investigate the possibilities of producing fuels. The production and systematic usage of solar fuels can reduce the use of fossil-based fuels, which are currently the primary source for the energy. It is time for us to exploit renewable sources for our energy needs to progress towards a low-carbon society. This can be achieved by utilizing green hydrogen as the future energy source. Solar light-assisted hydrogen evolution through photocatalytic water splitting is one of the most advanced approaches, but it is a non-spontaneous chemical process and restricted by a kinetically demanding oxidation evolution reaction. Sunlight is one of the essential sources for the photoreforming (PR) of biomass waste into solar fuels, or/and lucrative fine chemicals. Hydrogen production through photoreforming of biomass can be considered energy neutral as it requires only low energy to overcome the activation barrier and an alternate method for the water splitting reaction. Towards the perspective of sustainability and zero emission norms, hydrogen production from biomass-derived feedstocks is an affordable and efficient process. Widely used photocatalyst materials, such as metal oxides, sulphides and polymeric semiconductors, still possess challenges in terms of their performance and stability. Recently, a new class of materials has emerged as organic-inorganic hybrid (OIH) photocatalysts, which have the benefits of both components, with peculiar properties and outstanding energy conversion capability. This work examines the most recent progress in the photoreforming of biomass and its derivatives using OIHs as excellent catalysts for hydrogen evolution. The fundamental aspects of the PR mechanism and different methods of hydrogen production from biomass are discussed. Additionally, an interaction between both composite materials at the atomic level has been discussed in detail in the recent literature. Finally, the opportunities and future perspective for the synthesis and development of OIH catalysts are discussed briefly with regards to biomass photo-reforming.

Combinational application of metal-organic frameworks-based nanozyme and nucleic acid delivery in cancer therapy

The rapid development of nanotechnology has generated numerous ideas for cancer treatment, and a wide variety of relevant nanoparticle platforms have been reported. Metal-organic frameworks (MOFs) have been widely investigated as an anti-cancer drug delivery vehicle owing to their unique porous hybrid structure, biocompatibility, structural tunability, and multi-functionality. MOF materials with catalytic activity, known as nanozymes, have applications in photodynamic and chemodynamic therapy. Nucleic acids have also attracted increasing research attention owing to their programmability, ease of synthesis, and versatility. A variety of functional DNAs and RNAs have been applied both therapeutically (gene-targeting drugs for cancer treatment) and nontherapeutically (used as modified materials to enhance the therapeutic effects of other nanomedicines). The combined use of MOFs and functional nucleic acids have been extensively investigated and has been associated with excellent tumor-suppressor activity in various treatment methods. In this review, we summarize the progress in the research and development of tumor therapy based on MOFs and nucleic acid delivery over recent years, focusing on the combinational use of different delivery and design strategies for MOF/therapeutic nucleic acid platforms. We further summarize the strategies for combining MOFs (universal carrier, functional carrier) and nucleic acids (therapeutic nucleic acids, nontherapeutic nucleic acids) and discuss the corresponding therapeutic effects in cancer treatment. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Zr-based metal organic framework nanoparticles coated with a molecularly imprinted polymer for trace diazinon surface enhanced Raman scattering analysis

In this study, a new surface imprinted polymer of type MOFs-MIPs was synthesized with diazinon as template and Zr-based metal organic framework (UiO-67) as matrix for trace diazinon surface enhanced...

Gas–solid two-phase flow method for preparing trimesic acid series MOFs for catalytic thermal decomposition of ammonium perchlorate

The Zn–BTC, Co–BTC and Zn–Co–BTC series MOFs were prepared by using the GSF device and applied in the catalytic thermal decomposition of AP to change the high-temperature thermal decomposition peak of AP.

Interface assembly of specific recognition gripper wrapping on activated collagen fiber for synergistic capture effect of iodine

Efficient capture of radioactive iodine (¹²⁹I, ¹³¹I) is of great significance in spent fuel treatment. In this paper, a new adsorbent named Catechin@ACF was successfully prepared through interface assembly of specific recognition gripper with plant polyphenols (catechin) on activated collagen fiber (ACF), and the catechin membrane with specific grip on iodine was successfully constructed on the surface of ACF. The results showed that the adsorbent assembled catechin membrane was rich in aromatic rings, hydroxyl groups and imine adsorption sites, and possessed specific recognition and capture characteristics of iodine. Moreover, the as-prepared Catechin@ACF showed excellent capture capacity for iodine vapor and iodine in organic solution with the maximum capture capacity of 2122.68 mg/g and 258.29 mg/g, respectively. In iodine-cyclohexane solution, the adsorption process was in according with the Pseudo first order kinetic and Langmuir isothermal model. In addition, the specific recognition and capture mechanism analysis indicated that the aromatic rings, phenolic hydroxyl groups and imine groups in the catechin membrane were the specific and effective grippers for iodine, and finally iodine formed a stable conjugated system with the adsorbent in the form of I^- and I₃^-. Therefore, the as-prepared specific iodine capturer Catechin@ACF was expected to play a vital role in the capture of radioactive iodine in spent fuel off-gas because of its specific recognition, high capture capacity, large-scale preparation, and environment-friendly.

Study on Selected Metal-Organic Framework-Based Catalysts for Cycloaddition Reaction of CO2 with Epoxides: A Highly Economic Solution for Carbon Capture and Utilization

The level of carbon dioxide in the atmosphere is growing rapidly due to fossil fuel combustion processes, heavy oil, coal, oil shelter, and exhausts from automobiles for energy generation, which lead to depletion of the ozone layer and consequently result in global warming. The realization of a carbon-neutral environment is the main focus of science and academic researchers of today. Several processes were employed to minimize carbon dioxide in the air, some of which include the utilization of non-fossil sources of energy like solar, nuclear, and biomass-based fuels. Consequently, these sources were reported to have a relatively high cost of production and maintenance. The applications of both homogeneous and heterogeneous processes in carbon capture and storage were investigated in recent years and the focus now is on the conversion of CO2 into useful chemicals and compounds. It was established that CO2 can undergo cycloaddition reaction with epoxides under the influence of special catalysts to give cyclic carbonates, which can be used as value-added chemicals at a different level of pharmaceutical and industrial applications. Among the various catalysts studied for this reaction, metal-organic frameworks are now on the frontline as a potential catalyst due to their special features and easy synthesis. Several metal-organic framework (MOF)-based catalysts were studied for their application in transforming CO2 to organic carbonates using epoxides. Here, we report some recent studies of porous MOF materials and an in-depth discussion of two repeatedly used metal-organic frameworks as a catalyst in the conversion of CO2 to organic carbonates.

Asymmetric organocatalysis: an enabling technology for medicinal chemistry

The efficacy and synthetic versatility of asymmetric organocatalysis have contributed enormously to the field of organic synthesis since the early 2000s. As asymmetric organocatalytic methods mature, they have extended beyond the academia and undergone scale-up for the production of chiral drugs, natural products, and enantiomerically enriched bioactive molecules. This review provides a comprehensive overview of the applications of asymmetric organocatalysis in medicinal chemistry. A general picture of asymmetric organocatalytic strategies in medicinal chemistry is firstly presented, and the specific applications of these strategies in pharmaceutical synthesis are systematically described, with a focus on the preparation of antiviral, anticancer, neuroprotective, cardiovascular, antibacterial, and antiparasitic agents, as well as several miscellaneous bioactive agents. The review concludes with a discussion of the challenges, limitations and future prospects for organocatalytic asymmetric synthesis of medicinally valuable compounds.

Metal-organic frameworks as catalytic selectivity regulators for organic transformations

Selective organic transformations using metal-organic frameworks (MOFs) and MOF-based heterogeneous catalysts have been an intriguing but challenging research topic in both the chemistry and materials communities. Analogous to the reaction specificity achieved in enzyme pockets, MOFs are also powerful platforms for regulating the catalytic selectivity via engineering their catalytic microenvironments, such as metal node alternation, ligand functionalization, pore decoration, topology variation and others. In this review, we provide a comprehensive introduction and discussion about the role of MOFs played in regulating and even boosting the size-, shape-, chemo-, regio- and more appealing stereo-selectivity in organic transformations. We hope that it will be instructive for researchers in this field to rationally design, conveniently prepare and elaborately functionalize MOFs or MOF-based composites for the synthesis of high value-added organic chemicals with significantly improved selectivity.

Preparation and application of peptide molecularly imprinted material based on mesoporous metal-organic framework

In this study, a new molecularly imprinted material, MIP@UiO-66-NH₂, was synthesized with glutathione (GSH) as template and mesoporous metal organic framework (UiO-66-NH₂) as matrix. The molecularly imprinted polymer was modified on the surface and into the pores of the UiO-66-NH₂ by surface molecular imprinting method with thin polymer layer. Based on high specific surface area (1091.93 m² g^-1) and appropriate pore size (35 nm) of the ordered mesoporous UiO-66-NH₂, the adsorption capacity for GSH reached 94.43 mg g^-1, and the adsorption equilibrium could be achieved within 30 min. The adsorption isotherm data of MIP@UiO-66-NH₂ could be described well by Freundlich model and the kinetic data complied well with pseudo-second-order model. In addition, the MIP@UiO-66-NH₂ showed low adsorption capacity to GSH structural analogs (Q_L-cys = 6.51 mg g^-1), suggesting great selectivity for GSH recognition. Finally, the MIP@UiO-66-NH₂ was successfully applied for selective separation of GSH from BSA, skim milk and egg white tryptic digest.

Platinum-Supported Cerium-Doped Indium Oxide for Highly Sensitive Triethylamine Gas Sensing with Good Antihumidity

Triethylamine is extremely harmful to human health, and chronic inhalation can lead to respiratory and hematological diseases and eye lesions. Hence, it is essential to develop a triethylamine gas-sensing technology with high response, selectivity, and stability for use in healthcare and environmental monitoring. In this work, a simple and low-cost sensor based on the Pt- and Ce-modified In₂O₃ hollow structure to selectively detect triethylamine is developed. The experimental results reveal that the sensor based on 1% Pt/Ce₁₂In exhibits excellent triethylamine-sensing performance, including its insusceptibility to water, reduced operating temperature, enhanced response, and superior long-term stability. This work suggests that the enhancement of sensing performance toward triethylamine can be attributed to the high relative contents of O_V and O_C, large specific surface area, catalytic effect, the electronic sensitization of Pt, and the reversible redox cycle properties of Ce. This sensor represents a unique and highly sensitive means to detect triethylamine, which shows great promise for potential applications in food safety inspection and environmental monitoring.

Striking dual functionality of a novel Pd@Eu-MOF nanocatalyst in C(sp2)-C(sp2) bond-forming and CO2 fixation reactions

Pd nanoparticles were immobilized on a highly porous, hydrothermally stable Eu-MOF via solution impregnation and H2 reduction to yield a novel Pd@Eu-MOF nanocatalyst. This composite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), inductively coupled plasma optical emission spectroscopy (ICP-OES), powder X-ray diffraction (PXRD) and X-ray photoelectron spectroscopy (XPS). Unprecedentedly, the Pd@Eu-MOF nanocatalyst could be applied with excellent results in two strikingly different, mechanistically distinct, reactions i.e., Suzuki-Miyaura cross-coupling and cycloaddition of CO2 to a range of epoxides. Under the best reaction conditions, 98-99% yields have been attained in both catalytic processes. Moreover, in either case the heterogeneous catalyst was easily recovered and efficiently reused for more than four cycles, indicating its high stability and reproducibility. PXRD, TEM and XPS measurements on the recycled catalyst confirmed that it maintained its original structure and morphology; no Pd NP agglomeration was observed.

Hollow Fe3O4/carbon with surface mesopores derived from MOFs for enhanced lithium storage performance

Hollow metal-organic frameworks (MOFs) and their derivatives have attracted more and more attention due to their high specific surface area and perfect morphological structure, which determine their large potential application in energy storage and catalysis fields. However, few researchers have carried out further modification on the outer shell of hollow MOFs, such as the perforation modification, which will endow hollow nanomaterials derived from MOFs with multifunctionality. In this paper, hollow MOFs of MIL-53(Fe) with perforated outer surface are successfully synthesized by using SiO₂ nanospheres as the template via a self-assembly process induced by the coordination polymerization. The tightly packed mesopore structure makes the carbon outer shell of MOFs thinner, thus realizing the in-situ transformation from MOFs to hollow Fe₃O₄/carbon, which exhibits perfect capacity approaching 1270 mA h g^-1 even after 200 cycles at 0.1 A g^-1, as an anode material in lithium ion batteries (LIBs) application. This research provides a new strategy for the design and preparation of MOFs and their derivatives with multifunctionality for the energy applications.

Influence of pH and DO on the ofloxacin degradation in water by UVA-LED/TiO2 nanotube arrays photocatalytic fuel cell: mechanism, ROSs contribution and power generation

The influence of pH and dissolved oxygen (DO) on the degradation of ofloxacin (OFX) in water by UVA-LED/TiO₂ nanotube arrays photocatalytic fuel cell (UVA-LED/TNA PFC) was investigated. The degradation pathway depended on the location of OFX frontier orbital with different ionization states and the role of reactive oxidative species (ROSs) played with varied pH and DO values. In presence of DO, the quencher tests revealed that O₂^- played a key role at pH 3.0, 7.0 and 11.0, while OH made its greatest contribution at pH 3.0 and the effect of h⁺ was largely inhibited at pH 11.0. Hydroxylation for cationic OFX was more significant, while demethylation and piperazinyl ring oxidation for anionic OFX occurred more quickly compared to other forms. Besides, zwitterionic OFX underwent decarboxylation and combination of demethylation & hydroxylation more easily. Much higher power generation was observed in presence of DO at pH 7.0, probably due to the enhanced adsorption of OFX on the TNA, and DO could amplify the electric potential between the two electrodes. The degradation efficiencies were almost the same in presence or absence of DO, but the pathways were different and e-_aq may replace O₂- as the leading ROSs in absence of DO.

Metal organic frameworks for biomass conversion

This review narrates the recent developments on the catalytic applications of pristine metal–organic frameworks (MOFs), functionalized MOFs, guests embedded over MOFs and MOFs derived carbon composites for biomass conversion into platform chemicals.

Silver nanoparticles stabilized by a metal–organic framework (MIL-101(Cr)) as an efficient catalyst for imine production from the dehydrogenative coupling of alcohols and amines

In this paper, we present silver nanoparticles supported on a metal–organic framework (Ag@MIL-101) as a catalyst for the one-pot tandem synthesis of imines from alcohols and amines.

The synergistic role of the support surface and Au–Cu alloys in a plasmonic Au–Cu@LDH photocatalyst for the oxidative esterification of benzyl alcohol with methanol

The acid–base pairs of the support synergistic with Au–Cu alloy NPs could drive the oxidative esterification of benzyl alcohol with methanol.

Improving the photocatalytic hydrogen evolution of UiO-67 by incorporating Ce4+-coordinated bipyridinedicarboxylate ligands

UiO-67 is a Zr-based metal-organic framework (MOF) containing an organic linker namely, the dianion of biphenyl-4,4'-dicarboxylic acid (bpdc). Ce⁴⁺ metal ions (0.02 Ce to Zr atom ratio) were incorporated into UiO-67 via partially replacing bpdc with the dianion of 2,2'-bipyridine-5,5'-dicarboxylic acid (bpydc); thus, the latter forms a bpydc-Ce complex. The resulting product (i.e., UiO-67-Ce) demonstrated a photocatalytic hydrogen evolution rate that was over 10 times higher than that of UiO-67. Through this modification, a new energy transfer channel is opened up. The energy transfer between the bpdc and bpydc-Ce ligands (i.e., from excited bpdc to bpydc-Ce) weakened the recombination of the charge carriers, which was confirmed by photoluminescence, emission lifetime, and transient absorption measurements. This study presents a new way to construct highly efficient MOF photocatalysts.

Breaking Trade-Off between Selectivity and Activity of Nickel-Based Hydrogenation Catalysts by Tuning Both Steric Effect and d-Band Center

For selective hydrogenation of chemicals the high selectivity is always at the expense of activity and improving both selectivity and activity is challenging. Here, by chelating with p-fluorothiophenol (SPhF)-arrays, both steric and electronic effects are created to boost the performance of cheap nickel-based catalysts. Compared with dinickel phosphide, the SPhF-chelated one exhibits nearly 12 times higher activity and especially its selectivity is increased from 38.1% and 21.3% to nearly 100% in hydrogenations of 3-nitrostyrene and cinnamaldehyde. Commercial catalysts like Raney Ni chelating with SPhF-array also exhibits an enhanced selectivity from 20.5% and 23.4% to ≈100% along with doubled activity. Both experimental and density functional theory (DFT) calculation prove that the superior performance is attributed to the confined flat adsorption by ordered SPhF-arrays and downshifted d-band center of catalysts, leading to prohibited hydrogenation of the vinyl group and accelerative H2 activation. Such a surface modification can provide an easily-realized and low-cost way to design catalysts for the selective hydrogenation.

Partially Fluorinated Cu(I) Triazolate Frameworks with High Hydrophobicity, Porosity, and Luminescence Sensitivity

Solvothermal reactions of 3-methyl-5-trifluoromethyl-1,2,4-triazole (Hfmtz) with Cu(CH₃COO)₂ at 120 °C in the presence of Cl^- generate two partially fluorinated coordination polymers: i.e., [Cu₄Cl(fmtz)₃] (1 or MAF-51) and [Cu₇Cl(fmtz)₆] (2 or MAF-52). Single-crystal X-ray diffraction revealed 1 to have a three-dimensional (3D) nonporous structure with pcu topology consisting of 6-connected Cu₄(μ₄-Cl) clusters and 2 to possess a highly porous (void ratio 48%) 3D bnn network consisting of 5-connected Cu₅(μ₅-Cl) clusters. Benefiting from the hydrophobic pendant groups, complete coordination of the ligand N atoms, and strong M-N coordination bonds, 1 and 2 possess high water stability (exposed to water for at least 1 year) and hydrophobicity (water contact angles of 141° and 148°, respectively). The N₂ sorption isotherm of activated 2 gave Langmuir/BET surface areas of 1023/848 m² g^-1 and a pore volume of 0.365 cm³ g^-1. Moreover, 2 can adsorb large amounts of benzene and methanol but barely adsorb water. Both 1 and 2 show phosphorescence of Cu(I) complexes, but only that of porous 2 is sensitive to O₂, showing a linear Stern-Volmer response below 1 mbar with an ultrahigh K_sv value of 5234 bar^-1 and ultralow limit of detection of 1.9 ppm.

A flexible metal–organic framework with adaptive pores for high column-capacity gas chromatographic separation

A new zinc pyrazolyl-carboxylate framework with multi-mode and adaptive flexibility has been synthesized for efficient gas chromatographic separations.