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As alternatives to the expensive and increasing shortage of 3He for ultralow-temperature refrigeration, molecule-based magnetorefrigerant materials have attracted much attention in past decades. Among these, Gd(III)-based inorganic polymers, metal–organic frameworks, and coordination polymers with large magnetic densities and weak magnetic interactions have become a research focus. In this review, the synthesis, structures, and magnetism of Gd(III)-based inorganic polymers, metal–organic frameworks, and coordination polymers based on various inorganic and organic ligands are summarized and discussed, with an emphasis on the synthetic strategy towards molecular magnetorefrigerants with good stability and a large magnetocaloric effect. In addition, the conclusions and perspectives for Gd(III)-based magnetorefrigerants are presented and new insights for the further development of this promising area. Therefore, this review should serve as a tutorial for newcomers as well as a summary of the research progress in the field of magnetic refrigeration. [ABSTRACT FROM AUTHOR]

A lanthanide-based metal–organic framework (MOF) named SION-2 displays strong and tuneable uniaxial negative thermal expansion (NTE). The coefficient of thermal expansion α1 reaches −153(6) MK−1 between 100 and 340 K, which is the highest value reported to date for Ln-based MOFs. After heating to 380 K and subsequent cooling, the directionality and the magnitude of the effect change dramatically: the strong NTE effect is no longer observed along X1, while a much weaker NTE effect emerges in a perpendicular direction. Loss of non-coordinated N,N-dimethylformamide molecules together with the reduction of the size of structural voids stands as a rationale behind this switch-over. [ABSTRACT FROM AUTHOR]

Temperature-induced sorption in porous materials is a well-known process. What is more challenging is to determine how the rate at which temperature is varied affects these processes. To address this question, we introduce a methodology called ‘‘cyclic thermo-ellipsometry’’ to explore the thermo-kinetics of vapor physisorption in metal–organic framework films. [ABSTRACT FROM AUTHOR]

Thermodynamic analysis of gate-opening carbon dioxide (CO2) adsorption behavior of metal–organic frameworks (MOFs) was investigated using differential scanning calorimetry (DSC). Unlike measurements under nitrogen atmosphere, obvious exothermic and endothermic peaks were observed in DSC curves under CO2 flow. In situ heating X-ray diffraction and thermogravimetric analyses under CO2 revealed that reversible crystal structure and weight changes occurred upon CO2 adsorption/desorption. The thermodynamic parameters of the CO2 adsorption process by MOFs were determined by DSC analysis at various CO2 partial pressures. [ABSTRACT FROM AUTHOR]

Novel heterometallic formate [(CH3)2NH2][FeIIIMgII(HCOO)6] (DMFeMg) was prepared and characterized by single crystal X-ray diffraction, DSC, dielectric, magnetic susceptibility, Raman and IR methods. We also report thermal, Raman and IR studies of the known compound [(CH3)2NH2][FeIIIFeII(HCOO)6] (DMFeFe). DMFeMg crystallizes in the niccolite structure (P3̅1c space group). In contrast to the known DMFeFe, [(CH3)2NH2][FeIIIMnII(HCOO)6] (DMFeMn) and [(CH3)2NH2][FeIIICoII(HCOO)6] (DMFeCo) formates, the metal ions in DMFeMg are distributed statistically over the two available octahedral sites. Temperature-dependent studies show that whereas DMFeFe exhibits an order–disorder phase transition at 151.8 K upon cooling, freezing-in of re-orientational motions of DMA+ cations does not lead to any structural phase transition in DMFeMg. We discuss the origin of this difference. The low-temperature studies also show that DMFeMg orders magnetically at TC = 13.5(5) K and the shape of M(T) measured in the field-cooling regime suggests ferromagnetic character of the ordering. [ABSTRACT FROM AUTHOR]

Single-crystal-to-single-crystal post-synthetic modifications (PSMs) of Lanthanide Organic Frameworks (LOFs) {[Ln2(H2L)3(DMF)4]·2DMF}n (Ln = Gd, 1 and Eu, 2; H4L = 2,5-dihydroxyterephthalic acid; DMF = dimethylformamide), carried out by treatment with (a) chloroform or (b) an imidazole solution in chloroform, yielded respectively isostructural {[Ln2(H2L)3(DMF)4]·CHCl3}n (Ln = Gd, 3; Eu, 4) or {[Ln2(H2L)3(Im)4][Ln2(H2L)3(Im)2(H2O)2]·6Im·2CHCl3}n (Ln = Gd, 5; Eu, 6). Single crystal X-ray diffraction studies of 5 showed two different regularly alternating dimeric units in the LOF and two regularly alternating cavities with different guest molecules. All compounds revert to the parent LOF, 1 or 2, when treated with DMF at 90 °C for 8 h. Europium-LOFs (2, 4 and 6) showed a faint red emission that progressively gained intensity upon cooling from RT to liquid nitrogen temperature. This behaviour was exploited to develop a family of luminescent thermometers whose characteristics were affected by the structural and coordinative modifications induced by PSMs. [ABSTRACT FROM AUTHOR]

Two new neodymium-based metal–organic frameworks, JMS-10 and JMS-11, were synthesised using a 2,2′-bipypridine-5,5′-dicarboxylic acid (bpdc) linker. Both MOFs were solvothermally synthesised in DMF under different conditions. JMS-10 was synthesised at 120 °C while JMS-11 was synthesised at 100 °C in the presence of a modulator. Both the MOFs possessed very similar crystallographic parameters but were found to be structurally diverse. Their structures were built by secondary building units (SBUs) made up of carboxylates binding in sets of four and two to the straight rod, thus forming two types of alternating nodes that are 6- and 4-connected. Both JMS-10 and JMS-11 were functionalized using the ruthenium p-cymene complex. The functionalized MOFs were applied in the photocatalytic reduction of carbon dioxide to syngas where they produced both hydrogen and carbon monoxide (CO : H2) in the ratio of 1 : 2. The amount of CO to H2 produced varied depending on the additives used in the reaction medium, highlighting the importance of water, triethanolamine and acetonitrile in tuning the syngas ratio for different industrial applications. [ABSTRACT FROM AUTHOR]

Treatment of heavy metal pollution in complexed states within water bodies presents significant challenges in the current water treatment field. Adsorption as a means for the removal of heavy metals is characterized by its simplicity of operation, stable effluent, and minimal equipment requirements. Metal–organic frameworks (MOFs) as adsorbents hold significant interest for applications in water treatment. In this study, we investigated a green synthesis approach for the ball-milling pretreated synthesis of UiO-66(Zr) at room temperature, abbreviated as UiO-66(Zr)-rm. Besides having the same thermal stability and crystal structure as the product from microwave-assisted synthesis (UiO-66(Zr)-mw), the resulting UiO-66(Zr)-rm features smaller particle size and superior mesoporous structure. The adsorption efficiency and mechanism for removing EDTA-chelated copper (EDTA–CuII), a complexed heavy metal in water, were extensively analyzed. UiO-66(Zr)-rm presented a maximum adsorption capacity over EDTA–CuII of 43 mg g−1 and a much higher adsorption rate (0.16 g (mg h)−1) than UiO-66(Zr)-mw (0.06 g (mg h)−1). Hierarchically mesostructured defects allow the sorbate to have more effective diffusion in a shorter time to achieve faster adsorption kinetics. Benefiting from the mild synthesis conditions and nontoxic solvents, UiO-66(Zr) has the potential to be produced at a scaled-up level, thereby exhibiting excellent adsorption performance for the removal of complexed heavy metals in the future. [ABSTRACT FROM AUTHOR]

A novel MOF named [Zn2(L)(DMF)] was synthesized using solvothermal methods from the reaction of the new linker (4,4′,4′′-(4,4′,4′′-(benzene-1,3,5-triyltris(methylene))tris(3,5-dimethyl-1H-pyrazole-4,1-diyl))tribenzoic acid) and Zn(NO3)2·6H2O. This new MOF was characterized by means of different techniques: powder X-ray diffraction, N2 adsorption and desorption isotherms, thermogravimetric analysis, and scanning electron microscopy. Furthermore, suitable crystals were obtained, which allowed us to perform the X-Ray structure determination of this MOF. The capability of these new MOF to adsorb CO2 at different temperatures was measured and its isosteric enthalpy of adsorption was calculated. The novel MOF shows an uncommon node composed of a Zn3(–COO)6(DMF)2, and the asymmetric unit contains one crystallographically independent linker, one DMF molecule, and two Zn atoms. The [Zn2(L)(DMF)] MOF is a microporous material with high crystallinity and stability up to 250 °C. The multiple nitrogenated pyrazole linkers in its framework enhance its CO2 adsorption capabilities. This material exhibits a low CO2 isosteric enthalpy of adsorption (Hads), comparable to previously reported values for similar nitrogenated materials. All the observed CO2 adsorption capacities were further supported by DFT calculations. [ABSTRACT FROM AUTHOR]

The interaction between light and materials produces a range of phenomena within molecular systems, leading to advanced applications in the field of materials science. In this regard, metal–organic framework (MOF) materials have become superior candidates to others because of their easy tailor-made synthetic methods via incorporation of photoactive moieties into their structural assembly. Photoresponsive MOFs exhibit a massive variety of exciting properties, including photochromism, photomagnetism, photoluminescence, photon up or down conversion, photoconductivity, nonlinear optical properties, photosalient effects and photoinduced switching of conformations. These photoresponsive properties of MOFs regulate different potential applications, such as on-demand gas sorption and separation, optical sensing, fabrication of photoactuators and photosensing electronic devices, dye degradation, catalysis, cargo delivery, ink-free erasable printing, bio-imaging and drug delivery in biological systems. Therefore, judicious crystal engineering along with an understanding of their structure–property relationship will lead to the fabrication of desired photosensitive MOFs. Herein, we attempted to incorporate categorical descriptions based on advanced applications of photoresponsive MOFs considering a wide range of recent publications. [ABSTRACT FROM AUTHOR]

Single-phase white phosphors could overcome many drawbacks of traditional phosphors, and warm white light phosphors have been considered suitable for indoor illumination applications. Thus, synthesizing new single-phase warm white phosphors is significant for the production of LEDs. Based on the above considerations, a novel single component warm white light phosphor SmxTbyDy0.2−x−y-metal organic frameworks (MOFs) has been prepared successfully in this study. The compound Sm0.1Tb0.04Dy0.06-MOF shows ideal warm white light emission with CIE coordinates (0.333, 0.3522), a color rendering index (CRI) value of 86.7, a low correlated color temperature (CCT) value of 4444 K, and good heating/cooling circulation. In addition, the LED devices fabricated with this novel warm white light phosphor have excellent warm white light quality even at high temperatures, which is necessary for its practical application. [ABSTRACT FROM AUTHOR]

A novel hydrogen-bonded metal-organic framework (H-MOF) [Co(HL)2](DMF)1.2(H2O)2.4 (1·solv), in which L = 2,2′:6′,2′′-terpyridine-5,5"-diyl biscarboxylate, was prepared. An intermolecular single H-bond between carboxy and carboxylate sites was present in this compound. The crystal structure of 1·solv showed a 4-fold interpenetrating H-bonded diamond framework. After the desorption of the crystal solvents, 1·desolv exhibited normal and reverse spin-crossover (SCO) behaviours, providing an asymmetric thermal hysteresis loop. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. It includes a cover image by Gonzalo Campillo-Alvarado and an inside cover image by Shuai Wang and Xiaoyang Dai. The highlighted articles in this issue include one on multiple synthesis routes for atomically precise noble metal nanoclusters by Lizhong He and Tingting Dong, and another on co-crystal formation versus boron coordination in azopyridines by Jesus Daniel Loya, Sidhaesh A. Agarwal, Nicholas Lutz, Eric W. Reinheimer, and Gonzalo Campillo-Alvarado. The document also mentions professional development opportunities and provides a list of papers featured in the journal. [Extracted from the article]

Among the recent developments in metal–organic frameworks (MOFs), porous two-dimensional (2D) MOFs have garnered attention due to providing key technical supports, important energy-saving measures and precise chemical sensors for the green and sustainable society. Herein, two rare porous 2D Dy3+ MOFs, namely [Dy4L6(DMA)2(H2O)3]·7DMA (1, DMA = N,N-dimethylacetamide) and [Dy2L3(DMF)2]·DMF (2, DMF = N,N-dimethylformamide), have been successfully synthesized from reaction with 4,4′-(1,2-diphenylethene-1,2-diyl) dibenzoic acid (H2L) under different solvent systems. The main distinctions between the crystal structures of 1 and 2 arise from the differing solvent molecules residing within the pores which interact with the surrounding frameworks. These effects lead to different sizes of 1D channels. Importantly, different solvents of coordinated/free DMA molecules in 1 and DMF molecules in 2 induce the conversion of magnetic dynamics. Compound 1 exhibits obvious slow magnetic relaxation behavior under 0 Oe dc field, while zero-field out-of-phase signals of 2 exhibit no peaks in the whole temperature range. Compound 1 was magnetically characterized as a new example that the slow magnetic relaxation process can be observed in a 2D Dy3+ layer with 1D channels. Theoretical analysis based on ab initio calculation provides interpretations of magnetic observation. Additionally, compounds 1 and 2 have been tested as efficient fluorescent sensors for Fe3+ ions with high selectivity and sensitivity. The fluorescence quenching of 1 and 2 was demonstrated by an approximately 90% reduction in the emission intensity upon binding to Fe3+ ions. The emission intensities of 1 and 2 at 464 nm and 443 nm have shown linear responses to Fe3+ ion concentration with detection limits of 4.51 × 106 ppb and 6.90 × 106 ppb. [ABSTRACT FROM AUTHOR]

The shift from traditional bulky electronics to smart wearable devices represents a crucial trend in technological advancement. In recent years, the focus has intensified on harnessing thermal and mechanical energy from human activities to power small wearable electronics. This vision has attracted considerable attention from researchers, with an emphasis on the development of suitable materials that can efficiently convert human body energy into usable electrical form. Metal–organic frameworks (MOFs), with their unique tunable structures, large surface areas, and high porosity, emerge as a promising material category for human body energy harvesting due to their ability to be precisely engineered at the molecular level, which allows for the optimization of their properties to suit specific energy harvesting needs. This article explores the progressive development of MOF materials, highlighting their potential in the realm of self-power devices for wearable applications. It first introduces the typical energy harvesting routes that are particularly suitable for harvesting human body energy, including thermoelectric, triboelectric, and piezoelectric techniques. Then, it delves into various research advances that have demonstrated the efficacy of MOFs in capturing and converting body-generated energy into electrical energy, emphasizing on the conceptual design, device fabrication, and applications in medical health monitoring, human–computer interaction, and motion monitoring. Furthermore, it discusses potential future directions for research in MOF-based self-powered devices and outlines perspectives that could drive breakthroughs in the efficiency and practicality of these devices. [ABSTRACT FROM AUTHOR]

Two novel Ce(III) metal organic frameworks (MOFs) with formulas [Ce(5Meip)(H-5Meip)]nGR-MOF-17 and [CeCl(5Meip)(DMF)]nGR-MOF-18 (5Meip = 5-methylisophthalate, DMF = N,N-dimethylformamide) have been synthesized, forming 3-dimensional frameworks. Magnetic measurements show that both compounds present field-induced slow magnetic relaxation under a small applied dc field. For GR-MOF-17, the temperature dependence of relaxation times is best described by a Raman mechanism, whereas for GR-MOF-18, relaxation occurs through a combination of Raman and local-mode pathways. Moreover, when avoiding short Ce⋯Ce interactions by magnetic dilution in GR-MOF-17@La and GR-MOF-18@La, only the local-mode mechanism is responsible for magnetic relaxation. Photophysical studies show the occurrence of ligand-centred luminescence in both compounds and phosphorescence emission at low temperature for GR-MOF-17. [ABSTRACT FROM AUTHOR]

We report the synthesis, structures and gas sorption studies of two three-dimensional (3D) metal–organic frameworks (MOFs) namely {[Zn2(OBZ)2L1]·4DMF}n (1) and {[Co3(TER)3(L2)(DMF)]·5DMF}n (2), where OBZ2− is deprotonated 4,4′-oxybis(benzoic acid), TER2− is deprotonated terephthalic acid, DMF is N,N-dimethylformamide, L1 is 2,2′-bis(pyridin-3-ylmethyl)-[5,5′-biisoindoline]-1,1′,3,3′-tetraone and L2 is 5,5′-carbonylbis(2-(pyridin-3-ylmethyl)isoindoline-1,3-dione). 1 and 2 are 3D MOFs containing 2D channels. The desolvated phases of 1 and 2 (1-d and 2-d) adsorb modest amounts of carbon dioxide (CO2) at 195 K and 273 K; however, 1-d displays stepwise adsorption of CO2 at 195 K and hysteretic desorption. Notably, a gate-opening effect is triggered after 1-d adsorbs 63 cm3 (STP) g−1, allowing the structure to open and adsorb an additional 54 cm3 (STP) g−1. In contrast, 1-d adsorbs relatively small amounts of hydrogen (H2) and nitrogen (N2) gases, 3 cm3 (STP) g−1 and 12 cm3 (STP) g−1, respectively, suggesting selectivity of CO2 over H2 and N2. [ABSTRACT FROM AUTHOR]

The increasing CO2 emissions and their direct impact on climate change due to the greenhouse effect are environmental issues that must be solved as soon as possible. Metal–organic frameworks (MOFs) are one class of crystalline adsorbent materials that are thought to have enormous potential in CO2 capture applications. In this research, the effect of changing the metal center between Zr(IV), Ce(IV), and Hf(IV), and the linker between BDC and PDC has been fully studied. Thus, the six UiO-66 isoreticular derivatives have been synthesized and characterized by FTIR, PXRD, TGA, and N2 adsorption. We also report the BET surface area, CO2 adsorption capacities, kinetics, and the adsorption isosteric heat (Qst) of the UiO-66 derivatives mentioned family. The CO2 adsorption kinetics were evaluated using pseudo-first order, pseudo-second order, Avrami's kinetic models, and the rate-limiting step with Boyd's film diffusion, interparticle diffusion, and intraparticle diffusion models. The isosteric heats of CO2 adsorption using various MOFs are in the range 20–65 kJ mol−1 observing differences in adsorption capacities between 1.15 and 4.72 mmol g−1 at different temperatures due to the electrostatic interactions between CO2 and extra-framework metal ions. The isosteric heat of adsorption calculation in this report, which accounts for the unexpectedly high heat released from Zr-UiO-66-PDC, is finally represented as an increase in the interaction of CO2 with the PDC linker and an increase in Qst with defects. [ABSTRACT FROM AUTHOR]

Here we describe the synthesis of a compositional series of metal–organic framework crystalline-inorganic glass composites (MOF-CIGCs) containing ZIF-8 and an inorganic phosphate glass, 20Na2O–10NaCl–70P2O5, to expand the library of host matrices for metal–organic frameworks. By careful selection of the inorganic glass component, a relatively high loading of ZIF-8 (70 wt%) was achieved, which is the active component of the composite. A Zn⋯O–P interfacial bond, previously identified in similar composites/hybrid blends, was suggested by analysis of the total scattering pair distribution function data. Additionally, CO2 and N2 sorption and variable-temperature PXRD experiments were performed to assess the composites' properties. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have potential as drug carriers on the basis of their surface areas and pore volumes that allow for high drug loading and fast release. The present study investigated solvothermal synthesis and comprehensive characterization (BET, FTIR, PXRD and SEM) of two closely related series of microporous copper MOFs, Cu-MOF(s) (s = single linker) based on BPDC (biphenyl-4,4-dicarboxylate) linker and Cu-MOF(m) (m = mixed linker) comprising both BPDC and BPY (4,4-bipyridine) as linkers, for easy encapsulation and sustained delivery of two drugs, ibuprofen and montelukast sodium. Finally, one-way analysis of variance was applied for comparative evaluation between various concentration ratios (MOF : drug) to conclude statistically significant difference of encapsulation power and sustained release trend between the two Cu-MOFs using a UV-visible spectrophotometer by obtaining the absorbance value at λmax for each drug. Due to porous crystalline properties of our synthetized Cu-MOFs, we ensured excellent encapsulation and sustainability of both drugs to conceive a novel sustained release system for ibuprofen and montelukast sodium, which is more effective in comparison with conventional dosages of 2 to 3 times a day. [ABSTRACT FROM AUTHOR]

The construction of Z-scheme heterojunctions is still a challenge. Structure tailoring and energy band engineering of metal–organic frameworks (MOFs) permit the rational design and fabrication of Z-scheme MOF/graphene oxide (GO) heterojunctions to enhance photocatalytic performance. Herein, a novel Z-scheme Zn-MOF/GO heterojunction as an environmentally friendly, reusable, and highly efficient visible-light-induced photocatalyst for methylene blue (Mb) decoloration and/or Cr(VI) reduction was synthesized. The Zn-MOF/GO composite displayed much higher photodegradation performance than pure Zn-MOF. Besides, the photocatalytic performance of composites is related to the amounts of GO, and Zn-MOF/GO(15%) showed the best activity. Specifically, Zn-MOF/GO(15%) presented 92.6% Mb decoloration, 98.8% Cr(VI) reduction, and the simultaneous removal of Mb (87.9%) and Cr(VI) (99.8%) with good stability. The improved performance for Zn-MOF/GO(15%) can be due to the formation of the Z-scheme heterojunction and built-in electric field, which can not only promote the photogenerated electron–hole separation and transfer, but also broaden the spectrum of light absorption. Furthermore, the improved plausible photodegradation mechanism of Zn-MOF/GO(15%) was provided, and e−, h+ and ·OH were the primary reactive species during the photodegradation reactions. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have been widely explored and applied in many fields. However, the poor electrical conductivity of many traditional MOFs greatly limits their application in electrochemistry, especially in energy storage. In this study, a typical cMOF (Ni-HHTP, HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) was compounded with MXene nanosheets and a series of composites, namely MXene@Ni-HHTP-x (x = 1–8), were obtained. As a result, when MXene@Ni-HHTP-2 was assembled as a positive electrode material in an asymmetric supercapacitor, it achieved a specific capacitance of 416.6 F g−1 at 0.5 A g−1, manifesting a good performance in energy storage. [ABSTRACT FROM AUTHOR]

We present the synthesis and magneto-thermal properties of carborane-based lanthanide metal-organic frameworks (MOFs) with the formula {[(Ln)3(mCB-L)4(NO3)(DMF)n]·Solv}, where Ln = Dy or Tb, characterized by dc and ac susceptibility, X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD) and heat capacity measurements. The MOF structure is formed by polymeric 1D chains of Ln ions with three different coordination environments (Ln1, Ln2, Ln3) running along the b-axis, linked by carborane-based linkers thus to provide a 3D structure. Static magnetic measurements reveal that these MOFs behave at low temperature as a system of S* = 1/2 Ising spins, weakly interacting ferromagnetically along the 1D polymeric chain (J*/kB = +0.45 K (+0.5 K) interaction constant estimated for Dy-MOF (Tb-MOF)) and coupled to Ln ions in adjacent chains through dipolar antiferromagnetic interactions. The Dy MOF exhibits slow relaxation of magnetization through a thermally activated process, transitioning to quantum tunneling of the magnetization at low temperatures, while both compounds exhibit field-induced relaxation through a very slow, direct process. The maximum magnetic entropy changes (-ΔSmaxm) for an applied magnetic field change of 2-0 T are 5.71 J kg-1 K-1 and 4.78 J kg-1 K-1, for Dy and Tb MOFs, respectively, while the magnetocaloric effect (MCE) peak for both occurs at T ~ 1.6 K, approximately double that for the Gd counterpart. [ABSTRACT FROM AUTHOR]

In this work, a chiral core-shell microspheres composite, L-his-MIL-53-NH2@SiO2, was prepared through in situ growth and chiral post-modification strategies. The core-shell microspheres were applied as a novel chiral stationary phase for HPLC enantiomeric separation. Various racemates were separated on the L-his-MIL-53-NH2@SiO2 packed column using n-hexane/isopropanol as the mobile phase. The chiral column showed excellent separation efficiency for fourteen chiral compounds, including alcohols, alkanes, esters, phenols, ketones, and organic acids. The influence of injection mass and temperature on the separation performance of the chiral column were investigated. The relative standard deviations (n = 5) of the retention time and peak area by repeated separation of benzoin are 0.28% and 0.63%, respectively. The results show that the L-his-MIL-53-NH2@SiO2 packed column exhibited good reproducibility and stability. In addition, the chiral resolution ability of the L-his-MIL-53-NH2@SiO2 packed column was compared with that of a commercial chiral column (Chiralpak AD-H). The L-his-MIL-53-NH2@SiO2 packed column exhibits unique advantages in chiral separations that can be complementary to the commercial chiral column. It was demonstrated that the chiral core-shell microspheres composite L-his-MIL-53-NH2@SiO2 prepared based on in situ growth and chiral postmodification strategies has great potential for enantiomeric separation by HPLC. [ABSTRACT FROM AUTHOR]

A stable two-dimensional radical hydrogen-bonded metal–organic framework, constructed using a modified tetrathiafulvalene-tetrabenzoate ((2-Me)-H4TTFTB) linker and Cd2+ ions, exhibits a high electrical conductivity of 4.1 × 10−4 S m−1 and excellent photothermal conversion with a temperature increase of 137 °C in 15 s under the irradiation of a 0.7 W cm−2 808 nm laser. [ABSTRACT FROM AUTHOR]

Post-synthetic modification is gaining prominence as a highly effective strategy for enhancing the functionality of porous materials without significant structural changes. Recently, there is growing interest in research focusing on elevating proton conductivity through the post-synthetically incorporation of ionic liquids (ILs) into metal–organic frameworks (MOFs). This approach is pivotal as it not only addresses the viscosity challenges associated with ILs but also simultaneously resolves the issue of low proton conductivity observed in MOFs under anhydrous conditions. This review aims to provide initial insights into the field of IL-functionalized MOFs designed for enhanced proton conductivity and their composite of mixed matrix membranes (MMMs) for practical usability. [ABSTRACT FROM AUTHOR]

Herein, we present the synthesis and crystal structure of a series of heteronuclear metal–organic frameworks consisting of cobalt(II) and lanthanide(III) ions or yttrium(III) ions that are connected by oxydiacetato (oda2−) as a ligand. Our investigation led to the discovery of 16 new compounds that were categorized into two distinct structural types. Bigger lanthanide ions (La to Ho) and Y favor the formation of a neutral, highly porous hexagonal structure (space group P6/mcc). This assembly gives rise to nano-sized channels accommodating a significant number of crystallization water molecules (12–14 per formula unit). Conversely, smaller lanthanide ions (Sm to Lu) and Y favor the formation of an extended anionic cubic network neutralized by Co(II) hexaaqua ions (space group Fd3¯c). Both structures are assembled from the same building blocks, [Ln(oda)3]3− and Co(II), connected by either a syn–anti or an anti–anti carboxylate bridge. Both the hexagonal and cubic compounds show the same general formula [Ln2Co3(oda)6(H2O)6]·nH2O with different numbers of crystallization water molecules. Although the formation of different frameworks from the same combination of ligands and metal ions has already been reported, an exceptionally extended phenomenon is observed in this case, encompassing a total of seven isomers from Sm to Ho and Y. The synthesis of these compounds can be achieved either through a direct reaction at room temperature or by a hydrothermal reaction, and this has a marked influence on the obtained crystal structure. Our findings offer valuable data to discuss the rationale concerning the main chemical aspects of the synthetic strategies that can lead to the isolation of a unique pure phase, especially in systems where two structures are feasible. [ABSTRACT FROM AUTHOR]

Metal nanoparticles (MNPs) composited on metal–organic frameworks (MOFs) can generate valuable materials (MNP/MOF) possessing good physical, chemical, and biological properties. The preparation of novel MNP/MOF followed by exploration of their applications has inspired great investigational enthusiasm. In this paper, Ni, Co and Ni–Co bimetallic MNP/MOF catalysts derived from MOFs were prepared by controlled pyrolysis, and then characterized by TGA, FTIR, XRD, BET, SEM, XPS and H2-TPD, which showed that pyrolysis under H2 (reported typically under an inert atmosphere) and the addition of Co to Ni–MOF could form Ni–Co alloy MOFs with not only a relatively complete MOFs structure but good dispersion of metal nanoparticles. In order to disclose their potential for utilization, specifically, the activity tests of the prepared novel MNP/MOF materials were conducted on the hydrogenation of toluene towards methylcyclohexane. The results confirmed that the Ni1Co2/MOF-325 catalyst obtained by pyrolysis of Ni1Co2–MOF under H2 at 325 °C had high activity and good stability for the hydrogenation of toluene, showing excellent prospect as a hydrogenation catalyst. [ABSTRACT FROM AUTHOR]

Using the mixed-ligand strategy, three metal–organic frameworks were constructed by virtue of the solvothermal reaction. These compounds exhibit similar two-dimensional layered structures and serve as an efficient and economical porous heterogeneous catalyst for Knoevenagel condensation under mild conditions. The yields of Knoevenagel condensation can be reached between 96% and 99% in the presence of catalysts 1–3. Notably, the catalytic performance of 1 through reusability was explored, and it was observed that 1 could be reused up to six cycles with almost consistent catalytic efficiency. [ABSTRACT FROM AUTHOR]

Highly connected molecular building blocks (MBBs) have been demonstrated to play a crucial role in reticular chemistry, particularly in predicting the topologies of metal–organic frameworks. Metal phosphonate clusters exhibit considerable advantages in constructing high-connectivity MBBs, owing to the multiple coordination modes offered by phosphonic ligands. Herein, four metal (M = CoII, MnII) phosphonocarboxylate frameworks (CoPCF-1,2 and MnPCF-1,2) were successfully prepared under solvothermal conditions by utilizing the phosphonocarboxylic ligand, 4′-phosphonobiphenyl-3,5-dicarboxylic acid (H4pbpdc), and their structural characterization was performed using single-crystal X-ray diffraction (SCXRD). The structures feature a duodenary nuclear M12(µ3-OH)2(CO2)12(PO3)6(DMF)6/(CH3COO)4.5 cluster, bearing resemblance to the well-known Wells–Dawson ion from polyoxometallate chemistry. It is the first time a Wells–Dawson type cage has served as an 18-connected molecular building block, forming two kinds of porous metal phosphonocarboxylate frameworks with novel (3,18)-connected gez and gea topologies. Their permanent porosities were confirmed through N2 adsorption studies. Notably, the MBB Co12 cluster-based CoPCF-1 shows a loss and recovery process of µ3-OH through single-crystal-to-single-crystal (SCSC) transformation. The magnetic properties of the four compounds exhibit antiferromagnetic behavior. [ABSTRACT FROM AUTHOR]

While metal–organic framework (MOF) photocatalysts have demonstrated a unique Cr(VI) photoreduction capability in recent decades, their performance is still insufficient for practical applications because of their low Cr(VI) uptake and poor visible light response. To cope with these drawbacks, a new OH-modified Zr-based MOF, termed HCMUE-1, was successfully prepared via a solvothermal method in this work. The complete characterization of HCMUE-1 was performed through various techniques, including powder X-ray diffraction (PXRD), Raman spectroscopy, Fourier transform infrared (FT-IR), thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), scanning electron microscopy combined with energy-dispersive X-ray (SEM-EDX), and X-ray photoelectron spectroscopy (XPS). The obtained data exhibited the excellent Cr(VI) photoreduction efficiency of HCMUE-1, reaching up to 98% after 90 min and almost 100% after 120 min under visible light illumination in a low acidic medium. Noteworthily, HCMUE-1 retained the same Cr(VI) removal rate for at least seven cycles without considerable loss. Further experimental investigations demonstrated that the structural stability and surface morphology of HCMUE-1 were retained after photoreduction. Moreover, the photocatalytic reduction mechanism of Cr(VI) to Cr(III) was interpreted through a series of systematic experimental measurements. These results indicate that HCMUE-1 possesses potential as an efficient photocatalyst for reducing toxic Cr(VI) species from wastewater in real-life conditions. [ABSTRACT FROM AUTHOR]

In this study, we successfully synthesize cationic/neutral/anionic inverse-Hofmann-type spin crossover (SCO) frameworks with 1,1,2,2-tetrakis(4-(pyridine-4-yl)phenyl)-ethene ligand by means of cyanometallic charge engineering strategy. The cationic and neutral frameworks exhibit single-step thermally induced spin transition behaviors, while the SCO capability of anionic framework can be aroused by partial desolvation. This strategy provides a new idea to construct ionic SCO frameworks and extends the toolkit for SCO materials. [ABSTRACT FROM AUTHOR]

The construction of multifunctional metal-organic frameworks (MOFs) has attracted considerable attention. Two novel Dy-MOFs namely [Dy2(TPTC-2OMe)1.5(H2O)4·H2O]n (1) and {[Dy2(TPTC-2OMe)(H2TPTC-2OMe) (H2O)2]·2H2O}n (2) were obtained by a solvothermal method using 2′,5′-dimethoxy-[1,1′:4′,1″-terphenyl]- 4,4″-dicarboxylic acid (H4TPTC-2OMe) as the ligand. Structure analysis demonstrates that both MOFs 1 and 2 displayed three-dimensional framework structures, in which MOF 1 was with Dy(III) metal chains as nodes, while MOF 2 was with Dy2 binuclear metal clusters as nodes. Interestingly, MOFs 1 and 2 exhibited high thermal and chemistry stabilities and presented relatively high proton conductivity (σ) values of 1.69 × 10-4 S cm-1 and 3.52 × 10-6 S cm-1 at 50 °C and 98% RH. Although there exist a large number of coordinated or free H2O molecules in both structures, it is easier to form an ordered hydrogen-bonding network between the coordinated H2O molecules in the structure of MOFs, resulting in a more excellent proton conductivity of MOF 1. Moreover, MOF 1 exhibited field-induced single-molecule magnet (SMM) behavior with energy barriers (Ueff) of 37.22 K (τ0 = 9.27 × 10-8 s). Furthermore, MOF 1 exhibits obvious second-order nonlinear optical properties. This research provides guidance for the design of novelty multifunctional MOF materials. [ABSTRACT FROM AUTHOR]

The effective integration of nanomaterials with underlying current collectors is a key factor affecting the performance of nonenzymatic glucose sensors, where an inappropriate integration structure often leads to poor electron transport and instability. In this work, a seamless integrated electrode was constructed by the in situ immobilizing of a nickel-based metal-organic framework (Ni-MOF) on a three-dimensional (3D) conductive nickel foam (NF) for highly sensitive and durable glucose sensing. Facilitated by a rapid microwave-assisted reaction, a robust interfacial interaction between the Ni-MOF and the substrate was established through in situ conversion from nickel oxide (NiO). The fabricated Ni-MOF/NF electrode exhibits an excellent limit of detection (LOD) of 2.65 μM and an impressive sensitivity (14.31 mA cm-2 mM-1) within the linear range (4-576 μM), which is significantly boosted compared with that of an electrode prepared by a typical drop-casting method (3.56 mA cm-2 mM-1 in 4-1836 μM). Characterization and electrochemical tests reveal that this integrated structure on the one hand contributes to fast electron transport and thus has enhanced sensitivity and on the other hand leads to exceptional durability with its structural integrity maintained under bending, shaking, and ultrasonication. Moreover, this seamless integration method was also employed to immobilize the Ni-MOF converted from the pre-chemically deposited NiO layer on another type of substrate, 3D carbon paper (CP), demonstrating the versatility of this facile strategy in creating diverse electrochemical electrodes for applications beyond glucose sensing. [ABSTRACT FROM AUTHOR]

The selective photocatalytic oxidation of benzene to phenol under mild conditions is of great significance for the next-generation phenol industry. In this study, a cerium-nitrogen co-doped ironbased metal-organic framework heterogeneous catalyst (Ce/N-MOF(Fe)@P-C3N4) has been synthesized by a one-step solvothermal method. Under optimized experimental conditions, the synthesized Ce/N-MOF(Fe)@P-C3N4-b photocatalyst showed up to 16.4% yield and 96% selectivity in the direct photocatalytic hydroxylation of benzene to phenol, and the photocatalytic performance did not decrease sharply after five cycles, indicating good stability and reusability. The improved strategy for this catalyst will provide some new insights for the development of more efficient photocatalysts for the direct hydroxylation of benzene to phenol. [ABSTRACT FROM AUTHOR]

The pore structure of metal-organic frameworks (MOFs) is crucial to their adsorption performance, and it is still a challenge to precisely control the pore size to realize superior removal of uranium. The pore size of MOF-A, MOF-B and MOF-C was fine-tuned by using three organic chains with different lengths (fumaric acid, terephthalic acid and naphthalene dicarboxylic acid, respectively). The synthesized MOF-A, MOF-B and MOF-C had ordered increase in pore sizes with 3.8 Å, 5.7 Å and 7.6 Å, respectively. Pore size of 7.6 Å in MOF-C was a little larger than the geometric dimension of the UO22+ ion (maximum length 6.04-6.84 Å), which facilitated diffusion of UO22+ ions and achieved highly efficient adsorption. The maximum adsorption capacity (584 mg g-1) and removal rate (99.75%) of uranium for MOF-C were higher than those for MOF-A and MOF-B. The excellent adsorption performance of MOF-C was attributed to the specific pore structure of MOF-C and effective complexation of oxygen-containing groups with U(VI). Our work proposes a new strategy for the outstanding removal of uranium by using different organic chains to precisely regulate the pore size of MOF. [ABSTRACT FROM AUTHOR]

The structural knowledge of metal-organic frameworks is crucial to the understanding and development of new efficient materials for industrial implementation. This review classifies and discusses recent advanced literature reports on phase transitions that occur during thermal treatments on metal-organic frameworks and their characterisation. Thermally activated phase transitions and procceses are classified according to the temperaturatures at which they occur: high temperature (reversible and non-reversible) and low temperature. In addition, theoretical calculations and modelling approaches employed to better understand these structural phase transitions are also reviewed. [ABSTRACT FROM AUTHOR]

The sensing of organic solvents and the determination of their water content are necessary conditions for ensuring environmental safety and organic solvent use. Herein, we selected a water-stable Cd-MOF, possessing 2D layers and amine groups, and optimized the synthesis conditions. The intensity of emission peaks gradually weakens with the increase in excitation wavelength in the range of 290–350 nm. The luminescent emission peaks exhibits a significant red shift with an increase in excitation wavelength at 355–400 nm. Tetrahydrofuran (THF) can significantly enhance the luminescent intensity of Cd-MOF compared to the others. Even in the presence of 5% volume fraction of other solvents, THF still shows a strong enhancement effect. These results confirm that this Cd-MOF can quickly and selectively detect THF through luminescent "turn on". Furthermore, the emission intensity of the Cd-MOF in THF gradually recedes with the increase in water, indicating its potential for the determination of water content of THF. The corresponding limit of detection is 0.14%, lower than that of some reported compounds. The interaction of THF and the amine groups of the ligand may lead to this specific enhancement of luminescence. In addition, the mixed matrix membrane with the functionality of MOF materials and the processability of polymers was synthesized, which can detect Fe3+, CrO42−, and Cr2O72− in water. [ABSTRACT FROM AUTHOR]

The design and synthesis of a Gd(III) metal–organic framework with the formula [Gd4(BTDI)3(DMF)4]n (JXUST-40, H4BTDI = 5,5′-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid) are reported hererin. Interestingly, a reversible single-crystal-to-single-crystal transition between JXUST-40 and {[Gd4(BTDI)3(H2O)4]·6H2O}n (JXUST-40a) was achieved under the stimulation of heat and solvents. Both JXUST-40 and JXUST-40a exhibited good stability when soaked in common solvents and aqueous solutions with pH values of 1–12. Magnetic studies showed that JXUST-40a has a larger magnetocaloric effect with –ΔS maxm = 26.65 J kg−1 K−1 at 2 K and 7 T than JXUST-40 due to its larger magnetic density. Structural analyses indicated that the coordinated solvent molecules play a crucial role in the coordination environment around the Gd(III) ions and the change in the framework, ultimately leading to the changes in the pore size and magnetism between JXUST-40 and JXUST-40a. In addition, both isomorphic [Dy4(BTDI)3(DMF)4]n (JXUST-41) and {[Dy4(BTDI)3(H2O)4]·6H2O}n (JXUST-41a) displayed slow magnetic relaxation behaviour. [ABSTRACT FROM AUTHOR]

Noble metal-based catalysts such as RuO2 and IrO2 are widely used in the catalysis of the OER. However, because of their high price and poor stability, it is urgent to develop transition metal-based electrocatalysts with low precious metal doping as an alternative. Layered double hydroxides (LDHs) grown on 3D metal–organic frameworks (MOFs) are ideal for doping precious metals owing to abundant defects at the heterointerface, large surface area, and intrinsic oxygen evolution activity. In this study, a novel FeNi LDH/MOF heterostructure was prepared via a two-step solvothermal method using Fe-soc-MOFs as the substrate. Subsequently, Ru was introduced through a hydrothermal process. The as-synthesized Ru@FeNi LDH/MOF has an overpotential of only 242 mV at a current density of 10 mA cm−2 and can be used in continuous electrolysis for 48 h. Its unique nanocubic core–shell structure and flower-like LDHs on its surface provide a large number of active sites, which become the key to ensuring high activity and stability. With the doping of Ru, the electronic structure was adjusted and electron transfer was accelerated, further improving electrochemical activity. This study provides a new idea for developing transition metal-based catalysts with low noble metal loading. [ABSTRACT FROM AUTHOR]

Conventional small-scale adsorption chillers generally employ silica-gel/water or zeolite/water working pairs given the relatively high level of mesoporosity and water affinity in these adsorbent materials. However, the coefficient of performance (COP) and specific cooling power (SCP) evaluated for the adsorption chiller using these adsorbent/adsorbate pairs cannot be still considered practically feasible in the context of a commercial system. Metal organic frameworks (MOFs) are not only characterized by much higher water adsorption capacities than these materials, but also can be mass-produced using much simpler methods than the template-assisted synthesis routes of most zeolites. However, the low intrinsic thermal conductivity of these materials limits their use as adsorbents in commercial-scale adsorption chillers. In this study, a novel composite composed of multi-walled carbon nanotubes (MWCNTs) incorporated in a MIL-100(Fe) framework has been synthesized using a molecular-level mixing process. The resulting composite, with varying volume fraction of MWCNTs, has been characterized for microstructure, degree of crystallinity, thermal stability, water sorption kinetics and hydrothermal cyclic stability for potential use as an adsorbent in commercial adsorption chillers. [ABSTRACT FROM AUTHOR]

A novel porous metal–organic framework Co(btc)(bpy) (Co-MOF-3a) was synthesized by employing a bipyridyl ligand, benzene tricarboxylic acid, and Co(NO3)2·6H2O and was completely characterized. The mesoporous nature of the MOF catalyst was confirmed using BET measurements. The confirmation of the proposed structure of Co-MOF-3a was also supported through a computational study. This MOF could serve as a highly efficient heterogeneous catalyst for the oxidation of a variety of alcohols with tert-butyl hydroperoxide (t-BuOOH) as an oxidant. Furthermore, the current catalytic approach facilitated the oxidative coupling reaction in one pot to obtain a wide range of biologically important molecules, such as benzimidazole, benzothiazole, quinozolones, and arylidene malononitrile. The high performance of the MOF could be due to the presence of both the metal and carboxylate group of the ligand. The recyclability and scalability of the catalyst was found to be efficient and suitable for commercial applications. [ABSTRACT FROM AUTHOR]

Specific and rapid detection of live Staphylococcus aureus (S.A) in environmental and food samples is critically important for protecting human health. In order to fulfill this purpose, two kinds of novel egg yolk antibody (IgY) immobilized immunomagnetic beads (IMBs; mSiO2-IgY and mMOF-IgY), with core–shell mSiO2 and mMOF as substrate, were prepared for selectively enriching S.A from samples. Furthermore, the IMBs with captured S.A were collected and re-dissolved in 0.5 mL PBS. After that, a cotton swab coated with sodium dodecylsulfate (SDS) was put in the solution to lyse S.A cells and emit ATP bioluminescence of the luciferin/luciferase system. Finally, a portable bioluminescence detector was used for quantification of ATP corresponding to S.A concentration. The results demonstrated that mMOF-IgY can enrich more S.A than mSiO2-IgY and emit a stronger signal. The reasons may be due to the higher immobilization amount of IgY on the IMBs. Under optimal conditions, the calibration line of S.A concentration was 10–105 CFU mL−1 by mMOF-IgY within 30 min. The low detection limit of S.A was 3 CFU mL−1. The results demonstrated that the assay takes much shorter time than plate counting. Its portability and excellent detection capability are suitable for rapid monitoring of specific pathogens in foods. [ABSTRACT FROM AUTHOR]

Metal-linker bonds serve as the "glue" that binds metal ions to multitopic organic ligands in the porous materials known as metal–organic frameworks (MOFs). Despite ample evidence of bond lability in molecular and polymeric coordination compounds, the metal-linker bonds of MOFs were long assumed to be rigid and static. Given the importance of ligand fields in determining the behaviour of metal species, labile bonding in MOFs would help explain outstanding questions about MOF behaviour, while providing a design tool for controlling dynamic and stimuli-responsive optoelectronic, magnetic, catalytic, and mechanical phenomena. Here, we present emerging evidence that MOF metal-linker bonds exist in dynamic equilibria between weakly and tightly bond conformations, and that these equilibria respond to guest–host chemistry, drive phase change behavior, and exhibit size-dependence in MOF nanoparticles. [ABSTRACT FROM AUTHOR]

The use of an appropriate preparation route is the key to immobilize active molecules into a host matrix with high loadings and stability. Herein, we demonstrate a simple and general strategy to immobilize ferrocene and its derivatives into ZIF-8 with high loadings of up to 4.3% Fe content. The unique host pore structure allows for the stabilization of guest molecules and effectively prevents their leaching. As a result, the obtained electrocatalysts exhibit competitive oxygen evolution reaction (OER) catalytic performance. Optimized Fc-CHO/ZIF-8 requires only a low overpotential of 238 mV to achieve 10 mA cm−2, along with a relatively small Tafel slope of 44.4 mV dec−1. This performance is superior to that of commercial IrO2, suggesting its potential application in electrochemical energy conversion. [ABSTRACT FROM AUTHOR]

Two organic ligands, one rigid and one flexible, were designed and used to construct two cobalt-based metal–organic frameworks (MOFs) with coligands to obtain 3D and 2D structures, respectively. Both the Co-based MOFs were pyrolyzed at different temperatures to obtain the derived materials, and their electrocatalytic hydrogen evolution properties were studied. The results show that the electrocatalytic hydrogen evolution performance of MOF derivatives based on the rigid ligand was better than that of MOF derivatives based on the flexible organic ligand. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique renowned for its ultra-high sensitivity. Extensive research in SERS has led to the development of a wide range of SERS substrates, including plasmonic metals, semiconductors, metal organic frameworks, and their assemblies. Some of these materials are also excellent photocatalysts, and by taking advantage of their bifunctional characteristics, the photocatalytic processes that occur on their surface can be monitored in situ via SERS. This provides us with unique opportunities to gain valuable insights into the intricate details of the photocatalytic processes that are challenging to access using other techniques. In this review, we highlight key development in in situ and/or real-time SERS-tracking of photocatalytic reactions. We begin by providing a brief account of recent developments in SERS substrates, followed by discussions on how SERS can be used to elucidate crucial aspects of photocatalytic processes, including: (1) the influence of the surrounding media on charge carrier extraction; (2) the direction of charge carrier transfer; (3) the pathway of photocatalytic activation; and (4) differentiation between the effects of photo-thermal and energetic electrons. Additionally, we discuss the benefits of tip-enhanced Raman spectroscopy (TERS) due to the ability to achieve high-spatial-resolution measurements. Finally, we address major challenges and propose potential directions for the future of SERS monitoring of photocatalytic reactions. By leveraging the capabilities of SERS, we can uncover new insights into photocatalytic processes, paving the way for advancements in sustainable energy and environmental remediation. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are widely used in the biomedical industry. In this study, we developed a new method for obtaining a metal–organic structure of strontium and terephthalic acid, Sr(BDC), and an alternative activation method for removing DMF from the pores. Sr(BDC) MOFs were successfully prepared and characterized by XRD, FTIR, TGA, and SEM. The importance of the activation steps was confirmed by TGA, which showed that the Sr(BDC)(DMF) sample can contain up to a quarter of the solvent (DMF) before activation. In our study, IR spectroscopy confirmed the possibility of removing DMF by ethanol treatment from the Sr-BDC crystals. A comparative analysis of the effect of the activation method on the specific surface and pore size of Sr-BDC and its sorption properties using the model drug doxorubicin showed that due to the undeveloped surface of the Sr-(BDC)(DMF) sample, it is not possible to obtain an adsorption isotherm and determine the pore size distribution, thus showing the importance of the activation step. Cytotoxicity and apoptosis assays were carried out to study the biological activity of MOFs, and we observed relatively low toxicity in the tested concentration range after 48 h, with over 92% cell survival for Sr(BDC)(DMF) and Sr(BDC)(260 °C), with a decrease only in the highest concentration (800 mg L−1). Similar results were observed in our apoptosis assays, as they revealed low apoptotic population generation of 2.52%, 3.23%, and 2.77% for Sr(BDC)(DMF), Sr(BDC) and Sr(BDC)(260 °C), respectively. Overall, the findings indicate that ethanol-activated Sr(BDC) shows potential as a safe and effective material for drug delivery. [ABSTRACT FROM AUTHOR]

Nanozymes, which possess similar catalytic activities to natural enzymes, are considered promising alternatives to natural enzymes. In the present study, a new bimetallic Fe/Mn metal–organic framework (MOF) nanomaterial was synthesized by doping Mn in MIL-101(Fe). Despite the low doping amount of Mn, the Fe/Mn MOF displayed remarkably enhanced peroxidase-like activity, catalyzing the conversion of chromogenic substrate ABTS to blue-green ABTS˙+. Subsequently, the addition of environmental pollutant aminophenol isomers induced different color changes in a solution, which provided a simple and feasible approach to differentiate them by the naked eyes. Based on the effect of aminophenol isomers on the absorption spectrum of ABTS˙+, colorimetric methods were developed to quantitatively determine m-AP and p-AP with detection limits of 0.13 μM and 0.20 μM, respectively. Furthermore, taking advantage of a smart phone software-color recognizer to analyze the RGB value, a rapid detection method for m-AP was proposed, offering a solution to detect m-AP in the absence of any analytical instruments. This work verified the essential role of doping Mn in enhancing the enzyme-like activity of nanozymes. Simultaneously, the proposed simple, rapid, and accurate sensing method provided a new option to differentiate and determine aminophenol isomers, which has great potential for environmental application. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) with uniform pore size and rich functionality are promising candidates for membrane materials. However, the relatively weak stability of MOFs inhibits their applications in liquid separation. Herein, we proposed a simple and efficient strategy for the preparation of a well-intergrown and stable Ni-MOF-74 tubular membrane by the self-conversion of a nickel-based nanosheet layer (Ni-NSL). In this method, the Ni-NSL not only serves as a metal source for promoting heterogeneous nucleation to achieve high-quality Ni-MOF-74 membranes, but also acts as an inorganic linker between the support and membrane for enhancing membrane stability. Owing to the existence of the Ni-NSL, a thin Ni-MOF-74 membrane with a thickness of ca. 2.5 μm was obtained. The membrane exhibited excellent pervaporation performance with a separation factor of 1094 and a flux of 1.75 kg m−2 h−1 for n-butanol dehydration. Furthermore, the as-prepared Ni-MOF-74 membrane has good stability for 120 h of the separation of n-butanol/water. Therefore, the Ni-MOF-74 membrane by the self-conversion strategy is very promising for pervaporation separation of n-butanol. [ABSTRACT FROM AUTHOR]