Diabetes affects millions of people worldwide and the number of diagnoses continues to climb annually. Though several effective medications and therapeutic methods have been developed to treat type 1 (T1DM) and type 2 (T2DM) diabetes mellitus, direct insulin injection remains the only effective treatment for insulin resistant (IR) diabetes patients. Here, we immobilize insulin in a crystalline mesoporous metal-organic framework (MOF), NU-1000, and obtain a high loading of ∼40 wt % in only 30 min. The acid-stable MOF capsules are found to effectively prevent insulin from degrading in the presence of stomach acid and the digestive enzyme, pepsin. Furthermore, the encapsulated insulin can be released from NU-1000 under simulated physiological conditions.

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Practical applications involving the magnetic bistability of single-molecule magnets (SMMs) for next-generation computer technologies require nanostructuring, organization, and protection of nanoscale materials in two- or three-dimensional networks, to enable read-and-write processes. Owing to their porous nature and structural long-range order, metal–organic frameworks (MOFs) have been proposed as hosts to facilitate these efforts. Although probing the channels of MOF composites using indirect methods is well established, the use of direct methods to elucidate fundamental structural information is still lacking. Herein we report the direct imaging of SMMs encapsulated in a mesoporous MOF matrix using high-resolution transmission electron microscopy. These images deliver, for the first time, direct and unambiguous evidence to support the adsorption of molecular guests within the porous host. Bulk magnetic measurements further support the successful nanostructuring of SMMs. The preparation of the first magnetic composite thin films of this kind furthers the development of molecular spintronics.

At the Hanford Site in southeastern Washington state, the U.S. Department of Energy intends to treat 56 million gallons of legacy nuclear waste by encasing it in borosilicate glass via vitrification. This process ineffectively captures radioactive pertechnetate (TcO4 –) because of the ion’s volatility, thereby requiring a different remediation method for this long-lived (t 1/2 = 2.1 × 105 years), environmentally mobile species. Currently available sorbents lack the desired combination of high uptake capacity, fast kinetics, and selectivity. Here, we evaluate the ability of the chemically and thermally robust Zr6-based metal–organic framework (MOF), NU-1000, to capture perrhenate (ReO4 –), a pertechnetate simulant, and pertechnetate. Our material exhibits an excellent perrhenate uptake capacity of 210 mg/g, reaches saturation within 5 min, and maintains perrhenate uptake in the presence of competing anions. Additionally, experiments with pertechnetate confirm perrhenate is a suitable surrogate. Single-crystal X-ray diffraction indicates both chelating and nonchelating perrhenate binding motifs are present in both the small pore and the mesopore of NU-1000. Postadsorption diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) further elucidates the uptake mechanism and powder X-ray diffraction (PXRD) and Brunauer–Emmett–Teller (BET) surface area analysis confirm the retention of crystallinity and porosity of NU-1000 throughout adsorption.

Krypton and xenon are important gases in many applications, including, but not limited to, electronics, lighting, and medicine. Separation of these two gases by cryogenic distillation is highly energy-intensive; however, adsorption-based separation processes provide an alternative strategy for isolating gases in high purity. The absence of strong interactions between these molecules and porous adsorbents has impeded the advancement of adsorptive separation of krypton and xenon. Herein, we capitalized on the modular nature of metal−organic frameworks (MOFs) to design a porous material which relies on gas confinement to separate krypton/xenon (Kr/Xe) mixtures. We solvothermally synthesized a new zirconium-based MOF, NU-403, which comprises a three-dimensional linker, bicyclo[2.2.2]octane-1,4dicarboxylic acid. Comprehensive gas adsorption measurements revealed that the linker dimensionality and MOF pore aperture dramatically affect the separation of xenon from krypton owing to the confinement of gas molecules inside the framework. Moreover, Kr/Xe selectivity increased significantly after postsynthetic defect healing, which further enhanced gas−framework interactions, demonstrating an effective strategy for enhancing krypton and xenon separation.

As chemists and materials scientists, it is our duty to synthesize and utilize materials for a multitude of applications that promote the development of society and the well-being of its...

The United States Environmental Protection Agency (EPA) recognizes atrazine, a commonly used herbicide, as an endocrine disrupting compound. Excessive use of this agrochemical results in contamination of surface and ground water supplies via agricultural runoff. Efficient removal of atrazine from contaminated water supplies is paramount. Here, the mechanism governing atrazine adsorption in Zr6-based metal–organic frameworks (MOFs) has been thoroughly investigated by studying the effects of MOF linkers and topology on atrazine uptake capacity and uptake kinetics. We found that the mesopores of NU-1000 facilitated rapid atrazine uptake saturating in <5 min and that the pyrene-based linkers offered sufficient sites for π–π interactions with atrazine as demonstrated by the near 100% uptake. Without the presence of a pyrene-based linker, NU-1008, a MOF similar to NU-1000 with respect to surface area and pore size, removed <20% of the exposed atrazine. These results suggest that the atrazine uptake capacity demonstrated by NU-1000 stems from the presence of a pyrene core in the MOF linker, affirming that π–π stacking is responsible for driving atrazine adsorption. Furthermore, NU-1000 displays an exceptional atrazine removal capacity through three cycles of adsorption–desorption. Powder X-ray diffraction and Brunauer–Emmett–Teller surface area analysis confirmed the retention of MOF crystallinity and porosity throughout the adsorption–desorption cycles.