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The interactions between uranium and non‐innocent organic species are an essential component of fundamental uranium redox chemistry. However, they have seldom been explored in the context of multidimensional, porous materials. Uranium‐based metal–organic frameworks (MOFs) offer a new angle to study these interactions, as these self‐assembled species stabilize uranium species through immobilization by organic linkers within a crystalline framework, while potentially providing a method for adjusting metal oxidation state through coordination of non‐innocent linkers. We report the synthesis of the MOF NU‐1700, assembled from U4+‐paddlewheel nodes and catecholate‐based linkers. We propose this highly unusual structure, which contains two U4+ ions in a paddlewheel built from four linkers—a first among uranium materials—as a result of extensive characterization via powder X‐ray diffraction (PXRD), sorption, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA), in addition to density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

The interactions between uranium and non‐innocent organic species are an essential component of fundamental uranium redox chemistry. However, they have seldom been explored in the context of multidimensional, porous materials. Uranium‐based metal–organic frameworks (MOFs) offer a new angle to study these interactions, as these self‐assembled species stabilize uranium species through immobilization by organic linkers within a crystalline framework, while potentially providing a method for adjusting metal oxidation state through coordination of non‐innocent linkers. We report the synthesis of the MOF NU‐1700, assembled from U4+‐paddlewheel nodes and catecholate‐based linkers. We propose this highly unusual structure, which contains two U4+ ions in a paddlewheel built from four linkers—a first among uranium materials—as a result of extensive characterization via powder X‐ray diffraction (PXRD), sorption, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA), in addition to density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

A rare three-dimensional catecholate-based Ce(III) metal–organic framework (MOF), denoted as NU-1701, has been synthesized and crystallographically characterized. Density functional theory calculations highlight various possible electronic transitions that may present in NU-1701. These transitions are competitive and indicate increased lanthanide character of Ce(III). [ABSTRACT FROM AUTHOR]

Accurately characterizing actinide oxides bound to metal–organic frameworks (MOFs) is important for designing MOFs as radioactive waste sorbents and catalytic supports. In this work, the zirconium MOF NU-1000 was post-synthetically modified through solvothermal deposition to include the uranyl (UO22+) ion and characterized via single-crystal X-ray diffraction. Bond lengths derived from the diffraction pattern and Raman spectroscopy indicate that UO22+ maintains its chemical properties upon deposition, while alcohol oxidation photocatalysis reveals photo-interactions between the pyrene linkers and the UO22+ ion. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOF) are a subclass of porous framework materials that have been used for a wide variety of applications in sensing, catalysis, and remediation. Among these myriad applications is their remarkable ability to capture substances in a variety of environments ranging from benign to extreme. Among the most common and problematic substances found throughout the world's oceans and water supplies is [UO2]2+, a common mobile ion of uranium, which is found both naturally and as a result of anthropogenic activities, leading to problematic environmental contamination. While some MOFs possess high capability for the uptake of [UO2]2+, many more of the thousands of MOFs and their modifications that have been produced over the years have yet to be studied for their ability to uptake [UO2]2+. However, studying the thousands of MOFs and their modifications presents an incredibly difficult task. As such, a way to narrow down the numbers seems imperative. Herein, we evaluate the binding behaviors as well as identify the specific binding sites of [UO2]2+ incorporated into six different Zr MOFs to elucidate specific features that improve [UO2]2+ uptake. In doing so, we also present a method for the determination and verification of these binding sites by Anomalous wide-angle X-ray scattering, X-ray fluorescence, and X-ray absorption spectroscopy. This research not only presents a way for future research into the uptake of [UO2]2+ into MOFs to be conducted but also a means to evaluate MOFs more generally for the uptake of other compounds to be applied for environmental remediation and improvement of ecosystems globally. [ABSTRACT FROM AUTHOR]

A defining characteristic of nearly all catalytically functional MOFs is uniform, molecular-scale porosity. MOF pores, linkers and nodes that define them, help regulate reactant and product transport, catalyst siting, catalyst accessibility, catalyst stability, catalyst activity, co-catalyst proximity, composition of the chemical environment at and beyond the catalytic active site, chemical intermediate and transition-state conformations, thermodynamic affinity of molecular guests for MOF interior sites, framework charge and density of charge-compensating ions, pore hydrophobicity/hydrophilicity, pore and channel rigidity vs. flexibility, and other features and properties. Collectively and individually, these properties help define overall catalyst functional behaviour. This review focuses on how porous, catalyst-containing MOFs capitalize on molecular-scale confinement, containment, isolation, environment modulation, energy delivery, and mobility to accomplish desired chemical transformations with potentially superior selectivity or other efficacy, especially in comparison to catalysts in homogeneous solution environments. [ABSTRACT FROM AUTHOR]