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Preorganization is an effective strategy for f-element separation, but the complexity of extractant synthesis hinders large-scale application. Here the authors discuss an alternative strategy induced by in situ self-assembly that borrows principles of multivalent cooperativity from Nature to separate f-elements. [ABSTRACT FROM AUTHOR]

The fundamental problem of point defects under different phase equilibrium conditions in zircon (ZrSiO 4 ) is carried out by first-principles calculation. The formation energies with the structural deformation of various native defects, i.e., single vacancy, interstitial, Frenkel and Schottky pairs at different charge states are calculated, which agree well with the available results. We identify V O 2 + shows an important role in non-stoichiometric regime of ZrSiO 4− x ( x  < 1). When Fermi level ( ε F ) locates close to the CBM, the V Zr 4 − becomes more easily observed than V O 2 + in O-rich environment. In turn, the most abundant interstitial defects are I Zr 4 + and I Si 4 + . The non-interacting Si Frenkel-pair, made of the association of quadruply charged defect in energy of 5.947 eV, is more likely to form than other type of Frenkel-pairs. By formation the complex defects associating partial and full Schottky defects requires higher formation energy. These results provide a good reference to understand storage state as well as disposal of excess weapons-grade Pu and high-actinide wastes. [ABSTRACT FROM AUTHOR]

Dissimilatory metal-reducing bacteria (DMRB) can harvest energy for growth and activities by respiring metals, but it is so far unknown whether DMRB can acquire crystalline-phase actinides. In the present study, we used Shewanella oneidensis MR-1 to investigate microbially-mediated dissolution and reduction of U(VI) in three uranyl(VI) borate and boronate crystals (i.e., UO 2 (CH 3 BO 2 )(H 2 O) (UCBO); UO 2 B 2 O 4 (UBO); and Na[(UO 2 )B 6 O 10 (OH)]·2H 2 O (NaUBO)). Comparison of the dissolved U(VI) concentrations between samples with and without bacteria indicates that MR-1 facilitated dissolution of UCBO and UBO. Based on the assumption that only dissolved U(VI) was reduced, U(VI) reduction was substantially underestimated for UCBO and NaUBO, indicating that MR-1 directly reduced crystalline U(VI) in these two compounds. Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis implied that interactions occurred between microbial ligands and the residual particles of uranyl compounds. We found that S. oneidensis MR-1 can mediate the dissolution and reduction of crystalline U(VI) through facilitated dissolution and consequent reduction of crystals or direct reduction of U(VI) in crystals. These results help evaluate the environmental fate of solid-phase U(VI), critical for predicting U transport and remediating U-contaminated sites. [ABSTRACT FROM AUTHOR]

During the solvothermal synthesis of a low-dimensional borate, KB 5 O 7 (OH) 2 ⋅2H 2 O, in the presence of Pu(III), single crystals of plutonium dioxide unexpectedly formed. Single crystals of PuO 2 also formed during the hydrothermal synthesis of another borate, Na 2 B 5 O 8 (OH)⋅2H 2 O, in the presence of Pu(III). The reactions were conducted at 170 °C and 150 °C, respectively, which are much lower temperature than previously reported preparations of crystalline PuO 2 . Yellow–green crystals with a tablet habit were characterized by single crystal X-ray diffraction and solid-state UV–vis–NIR absorption spectroscopy. The crystal structure was solved by direct methods with R 1 = 1.26% for 19 unique observed reflections. PuO 2 is cubic, space group Fm 3 ‾ m , and adopts the fluorite structure type. The lattice parameter was determined to be a = 5.421(5) Å giving a volume of 159.3(2) Å 3 . The absorption spectrum is consistent with Pu(IV). [ABSTRACT FROM AUTHOR]

Abstract: Novel crystalline actinide materials can be used to immobilize uranium and transuranium elements at radioactive waste disposal sites. However, the stability and dissolution of such phases are still poorly understood. In this study, we investigated the dissolution kinetics of two uranyl borates and one plutonyl borate, UO2B2O4 (UBO), Na[(UO2)B6O10(OH)]·2H2O (NaUBO), and PuO2[B8O11(OH)4] (PuBO), with three different ligands, i.e., bicarbonate, phosphate, and natural humic acid (HA). These actinide borates were chosen because they possess different topologies that may influence dissolution. In the presence of bicarbonate, the apparent steady-state concentration of dissolved U(VI) and surface area-normalized dissolution rates were much higher for UBO compared to NaUBO. Uranyl phosphate, most likely in the form of (UO2)3(PO4)2(H2O)4, was precipitated on the surface of residual particles of UBO and NaUBO with phosphate. The dissolution rate of PuBO in NaNO3 solution was much higher than UBO or NaUBO. This study revealed that actinide borate crystal dissolution was substantially influenced by crystalline structures of actinide borates and aqueous ligands. [Copyright &y& Elsevier]

Three new uranyl borates, K(UO2)(BO3) (1), Rb(UO2)(BO3) (2) and Cs(UO2)(BO3) (3) have been prepared using B2O3 fluxes at 1000 ºC. 1 and 3 can also be synthesized using potassium tetraborate tetrahydrate as a molten flux at 290 ºC, which provides a new low temperature route to prepare actinide borates. 1 possesses an a-uranophane anion sheet topology identical to that in the previously reported compounds Li(UO2)(BO3) and Na(UO2)(BO3). 2 and 3 display a new [UO5]1∞ anion topology with a basic building block of edge-sharing dimers comprised of (UO7)2 polyhedra. The A(UO2)(BO3) (A ¼ alkali metal) series shows a systematic structural evolution, which will be discussed in the main text. [ABSTRACT FROM AUTHOR]

The low-lying electronic transitions of the neptunyl(NpO22+) ion are characterized as either chargetransfer (CT)or intra- 5f. Comparison of these classes of electronic transitionsreveals significantly different photophysical properties, especiallyin vibronic coupling. An empirical model developed for analyses ofuranyl CT vibronic transitions is used here to simulate the absorption(excitation) spectra of neptunyl in two compounds of different chemicalcompositions and structural symmetries. Analyses reveal that CT vibroniccoupling in neptunyl has the same characteristics as that in typicaluranyl analogues. The primary profile of the CT spectra is similarfor neptunyl respectively with respect to chloride- and oxide-neptuniumbonding interactions. On the other hand, vibronic coupling to theCT transitions is significantly different from that of f-f transitions,even within a given neptunyl compound. Electronic energy levels, vibroniccoupling strength, and frequencies of various vibration modes wereevaluated for transitions to the excited states of different originsin the region from 8000 cm–1to 21000 cm–1for two neptunyl compounds. [ABSTRACT FROM AUTHOR]

The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB5O6(OH)6][BO(OH)2]·2.5H2O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO4−. Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials. [ABSTRACT FROM AUTHOR]

U(VI), Np(VI), and Pu(VI) borates with the formula AnO2[B8O11(OH)4] (An = U, Np, Pu) have been prepared via the reactions of U(VI) nitrate, Np(VI) perchlorate, or Pu(IV) or Pu(VI) nitrate with molten boric acid. These compounds are all isotypic and consist of a linear actinyl(VI) cation, AnO22+, surrounded by BO3 triangles and BO4 tetrahedra to create an AnO8 hexagonal bipyramidal environment. The actinyl bond lengths are consistent with actinide contraction across this series. The borate anions bridge between actinyl units to create sheets. Additional BO3 triangles and BO4 tetrahedra extend from the polyborate layers and connect these sheets together to form a three-dimensional chiral framework structure. UV-vis-NIR absorption and fluorescence spectroscopy confirms the hexavalent oxidation state in all three compounds. Bond-valence parameters are developed for Np(VI). [ABSTRACT FROM AUTHOR]

Four new uranyl borates, Li[UO2B5O9]·H2O (LiUBO-1), Ag[(UO2)B5O8(OH)2] (AgUBO-1), α-Cs[(UO2)2B11O16(OH)6] (CsUBO-1), and β-Cs[(UO2)2B11O16(OH)6] (CsUBO-2) were synthesized via the reaction of uranyl nitrate with a large excess of molten boric acid in the presence of lithium, silver, or cesium nitrate. These compounds share a common structural motif consisting of a linear uranyl, UO22, cation surrounded by BO3triangles and BO4tetrahedra to create an UO8hexagonal bipyramidal environment around uranium. The borate anions bridge between uranyl units to create sheets. Additional BO3triangles extend from the polyborate layers, and are directed approximately perpendicular to the sheets. In Li[(UO2)B5O9]·H2O, the additional BO3triangles connect these sheets together to form a three-dimensional framework structure. Li[UO2)B5O9]·H2O and β-Cs[(UO2)2B11O16(OH)6] adopt noncentrosymmetric structures, while Ag[(UO2)B5O8(OH)2] and α-Cs[(UO2)2B11O16(OH)6] are centrosymmetric. Li[(UO2)B5O9]·H2O, which can be obtained as pure phase, displays second-harmonic generation of 532 nm light from 1064 nm light. Topological relationships of all actinyl borates are developed. [ABSTRACT FROM AUTHOR]

Metal‐organic framework (MOF) based heterostructures, which exhibit enhanced or unexpected functionality and properties due to synergistic effects, are typically synthesized using post‐synthetic strategies. However, several reported post‐synthetic strategies remain unsatisfactory, considering issues such as damage to the crystallinity of MOFs, presence of impure phases, and high time and energy consumption. In this work, we demonstrate for the first time a novel route for constructing MOF based heterostructures using radiation‐induced post‐synthesis, highlighting the merits of convenience, ambient conditions, large‐scale production, and notable time and energy saving. Specifically, a new HKUST‐1@Cu2O heterostructure was successfully synthesized by simply irradiating a methanol solution dispersed of HKUST‐1 with gamma ray under ambient conditions. The copper source of Cu2O was directly derived from in situ radiation etching and reduction of the parent HKUST‐1, without the use of any additional copper reagents. Significantly, the resulting HKUST‐1@Cu2O heterostructure exhibits remarkable catalytic performance, with a catalytic rate constant nearly two orders of magnitude higher than that of the parent HKUST‐1. [ABSTRACT FROM AUTHOR]

As a critical radioactive anionic contaminant, traditional adsorbents primarily remove iodate (IO3−) through ion exchange or hard acid‐hard base interactions, but suffer from limited affinity and capacity. Herein, employing the synergistic effect of ion exchange and redox, we successfully synthesized a redox‐active cationic polymer network (SCU‐CPN‐6, [C9H10O2N5 ⋅ Cl]n) by merging guanidino groups with ion‐exchange capability and phenolic groups with redox ability via a Schiff base reaction. SCU‐CPN‐6 exhibits a groundbreaking adsorption capacity of 896 mg/g for IO3−. The inferior adsorption capacities of polymeric networks containing only redox (~0 mg/g) or ion exchange (232 mg/g) fragments underscore the synergistic "1+1>2" effect of the two mechanisms. Besides, SCU‐CPN‐6 shows excellent uptake selectivity for IO3− in the presence of high concentrations of SO42−, Cl−, and NO3−. Meanwhile, a high distribution coefficient indicates its exemplary deep‐removal performance for low IO3− concentration. The synergic strategy not only presents a breakthrough solution for the efficient removal of IO3− but also establishes a promising avenue for the design of advanced adsorbents for diverse applications. [ABSTRACT FROM AUTHOR]

Two‐electron oxidative addition is one of the most important elementary reactions for d‐block transition metals but it is uncommon for f‐block elements. Here, we report the first examples of intermolecular oxidative addition of E−H (E=C, N) bonds to uranium(II) centers. The transient U(II) species was formed in‐situ by reducing a heterometallic cluster featuring U(IV)‐Pd(0) bonds with potassium‐graphite (KC8). Oxidative addition of C−H or N−H bonds to the U(II) centers was observed when this transient U(II) species was treated with benzene, carbazole or 1‐adamantylamine, respectively. The U(II) centers could also react with tetracene, biphenylene or N2O, leading to the formation of arene reduced U(IV) products and uranyl(VI) species via two‐ or four‐electron processes. This study demonstrates that the intermolecular two‐electron oxidative addition reactions are viable for actinide elements. [ABSTRACT FROM AUTHOR]

In conjunction with theoretical calculations, the in vitro and in vivo uranyl binding capabilities of a bidentate picolinate (Pic) ligand and its pentadentate derivative (H2dpa) are investigated. The planar N3O2-donor configuration of H2dpa matches the typical pentagonal-bipyramid coordination geometry of uranyl, demonstrating a remarkable removal preference for uranyl in the kidneys. [ABSTRACT FROM AUTHOR]

A new neutral borate species, H2B4O7 (also known as tetraboric acid), with a one-dimensional chain structure, is found in the interlayer spacing in Rb2[(UO2)2B8012F6].H2B4O7 (RbUBOF-2) derived from boric acid flux reaction of uranyl(Vl) nitrate with RbBF4. This new form of tetraboric acid possesses a novel borate fundamental building block with the symbol 4Δ:(3Δ)Δ. [ABSTRACT FROM AUTHOR]

The boric acid flux reaction of N

A new neptunium(V) borate, K[(NpO2)B10O14 (OH) 4], was synthesized using boric acid as a reactive flux. The compound possesses a layered structure in which NpV resides in triangular holes, creating a hexagonal-bipyramidal environment around neptunium. This compound is unusual in that it exhibits the Alexandrite effect, a property that is typically restricted to neptunium(IV) compounds. [ABSTRACT FROM AUTHOR]

A Np(V) compound containing three-center cation-cation interations, K(NpO2)3(H2O)Cl4, has been prepared by reacting Np(V) with KCl in molten boric acid. This compound forms a three-dimensional channel structure that is constructed from both two- and three-center cation-cation interactions. Three new bonding modes for cation-cation interactions are added to the summary of all known Np(V) compounds. [ABSTRACT FROM AUTHOR]

The first plutonium(III) borate, Pu2[B12O18(OH)4Br2(H2O)3]·0.5H2O, has been prepared by reacting plutonium(III) with molten boric acid under strictly anaerobic conditions. This compound contains a three-dimensional polyborate network with triangular holes that house the plutonium(III) sites. The plutonium sites in this compound are 9- and 10-coordinate and display atypical geometries. [ABSTRACT FROM AUTHOR]

The reaction of Np(v) chloride with molten boric acid results in the disproportionation of Np(v) into Np(iv) and Np(vi), and the crystallization of K2[(NpO2)3B10O16(OH)2(NO3)2]. UV-vis-NIR spectroscopy demonstrates that in addition to the Np(vi) and Np(v) found in the crystal structure, Np(iv) is also present. [ABSTRACT FROM AUTHOR]

Efficient adsorption of palladium ions from acid nuclear waste solution is crucial for ensuring the safety of vitrification process for radioactive waste. However, the limited stability and selectivity of most current adsorbents hinder their practical applications under strong acid and intense radiation conditions. Herein, to address these limitations, we designed and synthesized an aryl‐ether‐linked covalent organic framework (COF‐316‐DM) grafted dimethylthiocarbamoyl groups on the pore walls. This unique structure endows COF‐316‐DM with high stability and exceptional palladium capture capacity. The robust polyarylether linkage enables COF‐316‐DM to withstand irradiation doses of 200 or 400 kGy of β/γ ray. Furthermore, COF‐316‐DM demonstrates fast adsorption kinetics, high adsorption capacity (147 mg g−1), and excellent reusability in 4 M nitric acid. Moreover, COF‐316‐DM exhibits remarkable selectivity for palladium ions in the presence of 17 interference ions, simulating high level liquid waste scenario. The superior adsorption performance can be attributed to the strong binding affinity between the thioamide groups and Pd2+ ions, as confirmed by the comprehensive analysis of FT‐IR and XPS spectra. Our findings highlight the potential of COFs with robust linkers and tailored functional groups for efficient and selective capture of metal ions, even in harsh environmental conditions. [ABSTRACT FROM AUTHOR]

A radiochemistry laboratory presents potential radiological hazards due to the handling of multiple radionuclides with various half-lives and modes of radiation emission. To minimize these hazards, appropriate safety management and radiation protection strategies should be in place. The radiochemistry laboratory at Soochow University is one such workplace that handles therapeutic radionuclides, fission products, and actinides in liquid, solid, and gas forms. This work highlights the significance of using safety precautions and radiation protection strategies before conducting experiments in such laboratories. The practical knowledge gained from a case of radioactive contamination is discussed to provide valuable experience for safely conducting radiochemistry experiments. [ABSTRACT FROM AUTHOR]

Halide perovskites (HPs) recently have emerged as one class of competitive scintillators for X‐ray detection and imaging owing to its high quantum efficiency, short decay time, superior X‐ray absorption capacity, low cost, and ease of crystal growth. The tunable structure and versatile chemical compositions of halide perovskites provide distinguishable advantages over traditional inorganic scintillators for optimizing scintillation performance. Since the first observation of the scintillation phenomenon in HPs, substantial efforts have been devoted to expanding the inventory of HP scintillators and regulating material properties. Understanding the relationship between the structure and scintillation properties of HP scintillators is essential for developing materials with improved X‐ray detection and imaging capacities. This review summarizes strategies for improving the light yield of HP scintillators and provides a roadmap for improving the X‐ray imaging performance. Additionally, methods for controlling the light propagation direction in HP scintillators are highlighted for improving X‐ray imaging resolution. Finally, we highlight the current challenge in HP scintillators and provide a perspective on the future development of this emerging scintillator. [ABSTRACT FROM AUTHOR]

Halide perovskites (HPs) recently have emerged as one class of competitive scintillators for X‐ray detection and imaging owing to its high quantum efficiency, short decay time, superior X‐ray absorption capacity, low cost, and ease of crystal growth. The tunable structure and versatile chemical compositions of halide perovskites provide distinguishable advantages over traditional inorganic scintillators for optimizing scintillation performance. Since the first observation of the scintillation phenomenon in HPs, substantial efforts have been devoted to expanding the inventory of HP scintillators and regulating material properties. Understanding the relationship between the structure and scintillation properties of HP scintillators is essential for developing materials with improved X‐ray detection and imaging capacities. This review summarizes strategies for improving the light yield of HP scintillators and provides a roadmap for improving the X‐ray imaging performance. Additionally, methods for controlling the light propagation direction in HP scintillators are highlighted for improving X‐ray imaging resolution. Finally, we highlight the current challenge in HP scintillators and provide a perspective on the future development of this emerging scintillator. [ABSTRACT FROM AUTHOR]

The development of high‐performance X‐ray detectors requires scintillators with fast decay time, high light yield, stability, and X‐ray absorption capacity, which are difficult to achieve in a single material. Here, we present the first example of a lanthanide chalcogenide of LaCsSiS4 : 1 % Ce3+ that simultaneously integrates multiple desirable properties for an ideal scintillator. LaCsSiS4 : 1 % Ce3+ demonstrates a remarkably low detection limit of 43.13 nGyair s−1 and a high photoluminescence quantum yield of 98.24 %, resulting in a high light yield of 50480±1441 photons/MeV. Notably, LaCsSiS4 : 1 % Ce3+ exhibits a fast decay time of only 29.35±0.16 ns, making it one of the fastest scintillators among all lanthanide‐based inorganic scintillators. Furthermore, this material shows robust radiation and moisture resistance, endowing it with suitability for chemical processing under solution conditions. To demonstrate the X‐ray imaging capacity of LaCsSiS4 : 1 % Ce3+, we fabricated a flexible X‐ray detector that achieved a high spatial resolution of 8.2 lp mm−1. This work highlights the potential of lanthanide chalcogenide as a promising candidate for high‐performance scintillators. [ABSTRACT FROM AUTHOR]

The development of high‐performance X‐ray detectors requires scintillators with fast decay time, high light yield, stability, and X‐ray absorption capacity, which are difficult to achieve in a single material. Here, we present the first example of a lanthanide chalcogenide of LaCsSiS4 : 1 % Ce3+ that simultaneously integrates multiple desirable properties for an ideal scintillator. LaCsSiS4 : 1 % Ce3+ demonstrates a remarkably low detection limit of 43.13 nGyair s−1 and a high photoluminescence quantum yield of 98.24 %, resulting in a high light yield of 50480±1441 photons/MeV. Notably, LaCsSiS4 : 1 % Ce3+ exhibits a fast decay time of only 29.35±0.16 ns, making it one of the fastest scintillators among all lanthanide‐based inorganic scintillators. Furthermore, this material shows robust radiation and moisture resistance, endowing it with suitability for chemical processing under solution conditions. To demonstrate the X‐ray imaging capacity of LaCsSiS4 : 1 % Ce3+, we fabricated a flexible X‐ray detector that achieved a high spatial resolution of 8.2 lp mm−1. This work highlights the potential of lanthanide chalcogenide as a promising candidate for high‐performance scintillators. [ABSTRACT FROM AUTHOR]

The crystal structures of compounds (III), (IV), (VI) and (VII) are determined by single crystal XRD. [ABSTRACT FROM AUTHOR]

Periodically arranging coordination‐distinct actinides into one crystalline architecture is intriguing but of great synthetic challenge. We report a rare example of a heterobimetallic actinide metal–organic framework (An‐MOF) by a unique reaction‐induced preorganization strategy. A thorium MOF (SCU‐16) with the largest unit cell among all Th‐MOFs was prepared as the precursor, then the uranyl was precisely embedded into the MOF precursor under oxidation condition. Single crystal of the resulting thorium‐uranium MOF (SCU‐16‐U) shows that a uranyl‐specific site was in situ induced by the formate‐to‐carbonate oxidation reaction. The heterobimetallic SCU‐16‐U exhibits multifunction catalysis properties derived from two distinct actinides. The strategy proposed here offers a new avenue to create mixed‐actinide functional material with unique architecture and versatile functionality. [ABSTRACT FROM AUTHOR]

Periodically arranging coordination‐distinct actinides into one crystalline architecture is intriguing but of great synthetic challenge. We report a rare example of a heterobimetallic actinide metal–organic framework (An‐MOF) by a unique reaction‐induced preorganization strategy. A thorium MOF (SCU‐16) with the largest unit cell among all Th‐MOFs was prepared as the precursor, then the uranyl was precisely embedded into the MOF precursor under oxidation condition. Single crystal of the resulting thorium‐uranium MOF (SCU‐16‐U) shows that a uranyl‐specific site was in situ induced by the formate‐to‐carbonate oxidation reaction. The heterobimetallic SCU‐16‐U exhibits multifunction catalysis properties derived from two distinct actinides. The strategy proposed here offers a new avenue to create mixed‐actinide functional material with unique architecture and versatile functionality. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The second example of tetravalent plutonium carboxyl‐based organic framework, 242Pu(OH)[PO[(C6H4)COO]3]·H2O, termed as PuTPO (TPO = tris(4‐carboxylphenyl)‐phosphineoxide), was reported in this work. A series of characterizations of PuTPO, such as X‐ray crystallography and solid‐state UV‐Vis‐NIR spectroscopy, were carried out to expatiate its structure and physicochemical properties. PuTPO is constructed by dimers of the plutonium‐oxygen subunit of [Pu2O16]. Characteristic peaks located at approximately 1100 nm can be considered to be the fingerprint peaks of tetravalent plutonium. While PuTPO can maintain high crystallinity within several months after synthesis, it exhibits a radiation‐induced swelling effect probed by the expansion of cell parameter of b axis after self‐irradiation from α‐decay of 242Pu. This result enriches the inventory of tetravalent plutonium compounds and provides an insight into the irradiation resistance of metal‐organic frameworks. [ABSTRACT FROM AUTHOR]

Although examples of multiple bonds between actinide elements and main‐group elements are quite common, studies of the multiple bonds between actinide elements and transition metals are extremely rare owing to difficulties associated with their synthesis. Here we report the first example of molecular uranium complexes featuring a cis‐[M→→ ${{\rm{ \mathbin{{\stackrel{\textstyle\rightarrow} { {\smash{\rightarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ U←← ${{\rm{ \mathbin{{\stackrel{\textstyle\leftarrow} { {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ M] core (M=Rh, Ir), which exhibits an unprecedented arrangement of two M→→ ${{\rm{ \mathbin{{\stackrel{\textstyle\rightarrow} { {\smash{\rightarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ U double dative bond linkages to a single U center. These complexes were prepared by the reactions of chlorine‐bridged heterometallic complexes [{U{N(CH3)(CH2CH2NPiPr2)2}(Cl)2[(μ‐Cl)M(COD)]2}] (M=Rh, Ir) with MeMgBr or MeLi, a new method for the construction of species with U−M multiple bonds. Theoretical calculations including dispersion confirmed the presence of two U←← ${{\rm{ \mathbin{{\stackrel{\textstyle\leftarrow} { {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ M double dative bonds in these complexes. This study not only enriches the U←← ${{\rm{ \mathbin{{\stackrel{\textstyle\leftarrow} { {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ M multiple bond chemistry, but also provides a new opportunity to explore the bonding of actinide elements. [ABSTRACT FROM AUTHOR]

Although examples of multiple bonds between actinide elements and main‐group elements are quite common, studies of the multiple bonds between actinide elements and transition metals are extremely rare owing to difficulties associated with their synthesis. Here we report the first example of molecular uranium complexes featuring a cis‐[M→→ ${{\rm{ \mathbin{{\stackrel{\textstyle\rightarrow} { {\smash{\rightarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ U←← ${{\rm{ \mathbin{{\stackrel{\textstyle\leftarrow} { {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ M] core (M=Rh, Ir), which exhibits an unprecedented arrangement of two M→→ ${{\rm{ \mathbin{{\stackrel{\textstyle\rightarrow} { {\smash{\rightarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ U double dative bond linkages to a single U center. These complexes were prepared by the reactions of chlorine‐bridged heterometallic complexes [{U{N(CH3)(CH2CH2NPiPr2)2}(Cl)2[(μ‐Cl)M(COD)]2}] (M=Rh, Ir) with MeMgBr or MeLi, a new method for the construction of species with U−M multiple bonds. Theoretical calculations including dispersion confirmed the presence of two U←← ${{\rm{ \mathbin{{\stackrel{\textstyle\leftarrow} { {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ M double dative bonds in these complexes. This study not only enriches the U←← ${{\rm{ \mathbin{{\stackrel{\textstyle\leftarrow} { {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }}}$ M multiple bond chemistry, but also provides a new opportunity to explore the bonding of actinide elements. [ABSTRACT FROM AUTHOR]

In this Frontier article, we pursue the sequestration of radionuclides from aqueous solution by using recently emerging metal–organic framework (MOF) materials. The design of MOF materials and their corresponding sorption properties towards radionuclides (137Cs, 90Sr, 238U, 79Se, and 99Tc) as well as their interaction mechanisms are highlighted. The present challenges and future prospects of removing radionulides with MOFs as sorbents are also demonstrated. [ABSTRACT FROM AUTHOR]

Efficient removal of iodide (I−) and iodate (IO3−) from aqueous solution is highly desirable for waste disposal and remediation of radioiodine contamination. We report here a bifunctional anion exchange resin Purolite A530E for the effective I−/IO3− adsorption, which shows a priority anion-exchange affinity for I− (99%) over IO3− (9.7%). The maximum adsorption capacity for I− is 275.16 mg·g−1 fitted by the Langmuir isotherm model, much higher than most adsorbents. Furthermore, Purolite A530E exhibits great selectivity for I− over competing anions, which endows the resin with promising I− remediation that over 99% I− can be removed from simulated Hanford groundwater (HGW). [ABSTRACT FROM AUTHOR]

The exceptional photophysical properties of 3D organic–inorganic lead halide hybrids (OILHs) endow their significant potential for usage in optoelectronics, which has sparked intense research on novel 3D OILHs and associated applications. However, constructing new 3D OILHs based on large organic cations suffers from tough challenges due to the limitation of the Goldschmidt tolerance factor rule, let alone further explorations of their practical applications. Herein, a brand‐new 3D lead chloride hybrid, (1MPZ)Pb4Cl10·H2O (1, 1MPZ = 1‐methylpiperazine) is reported, featuring a dense 3D lead chloride framework made of the corner‐, edge‐, and face‐shared lead chloride polyhedra. 1 presents a broadband white light emission with a large Stokes shift and a nanosecond photoluminescence lifetime, which originates from radiative recombination of self‐trapped excitons (STEs) induced by the highly distorted structure. Such a reabsorption‐free and fast‐decayed STEs emission coupling with the dense 3D architecture further enables 1 with effective X‐ray scintillation with good sensitivity. Impressively, 1 also shows superior environmental and radiation stability. This study provides a new 3D OILH with appealing luminescence, not only expanding the 3D OILH family but also inspiring the exploitation of their optoelectronic applications. [ABSTRACT FROM AUTHOR]

The Haber–Bosch process produces ammonia (NH3) from dinitrogen (N2) and dihydrogen (H2), but requires high temperature and pressure. Before iron-based catalysts were exploited in the current industrial Haber–Bosch process, uranium-based materials served as effective catalysts for production of NH3 from N2. Although some molecular uranium complexes are known to be capable of combining with N2, further hydrogenation with H2 forming NH3 has not been reported to date. Here, we describe the first example of N2 cleavage and hydrogenation with H2 to NH3 with a molecular uranium complex. The N2 cleavage product contains three uranium centers that are bridged by three imido μ 2-NH ligands and one nitrido μ 3-N ligand. Labeling experiments with 15N demonstrate that the nitrido ligand in the product originates from N2. Reaction of the N2-cleaved complex with H2 or H+ forms NH3 under mild conditions. A synthetic cycle has been established by the reaction of the N2-cleaved complex with trimethylsilyl chloride. The isolation of this trinuclear imido-nitrido product implies that a multi-metallic uranium assembly plays an important role in the activation of N2. [ABSTRACT FROM AUTHOR]

Reactions of LnCl3 (Ln: La-Nd, Sm, Eu) with 11 M HClO4 in molten H3BO3 (autoclave, 240 °C, 3, 5, or 7 d) lead to the formation of Ln[B8O10(OH)6(H2O) (ClO4)]·0.5H2O (Ln: La-Nd, Sm), Pr[B8O11(OH)4(H2O) (ClO4)], Ln[B7O11(OH)(H2O)2 (ClO4)] (Ln: Pr, Nd, Sm, Eu), and Ce[B8O11(OH)4(H2O) (ClO4)] depending on the lanthanide metal and the reaction time. [ABSTRACT FROM AUTHOR]

Rb2 [(UO2)2B8O12F6] ·H2B4O7 is synthesized from mixtures of UO2(NO3)2, H3BO3, RbBF4, and H2O (autoclave, 220 °C, 5 d). [ABSTRACT FROM AUTHOR]

As revealed by single crystal XRD compounds (III) and (VII) crystallize in the space group P21/n with Z = 4. [ABSTRACT FROM AUTHOR]

(UO2)2 [UO4(trz)2](OH)2 (trz: 1,2,4-triazole) is obtained under mild solvothermal conditions by reaction of uranyl acetate and 1,2,4-triazole in a mixed solution of EtOH, MeCN, and H2O (autoclave, 150 °C, 4 d, 42% yield). [ABSTRACT FROM AUTHOR]

Colorless crystals of Na[(NpO2)4B15O24 (OH)5(H2O)](ClO4)·0.75H2O are prepared by reaction of NpO2(ClO4)2 and NaClO4 in a boric acid flux (autoclave, 220 °C, 3 d). [ABSTRACT FROM AUTHOR]

Ba5 [(UO2)(PO4)3(B5O9)] (H2O)0.125 is synthesized by solid state reaction of H3BO3, BPO4, UO2(NO3)2·6H2O, and BaCO3 (Pt crucible, 1000 °C, slow cooling to room temperature, 8-10% yield). [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are a distinct family of crystalline porous materials finding extensive applications. Their synthesis often requires elevated temperature and relatively long reaction time. We report here the first case of MOF synthesis activated by high‐energy (1.5 MeV) electron beam radiation from a commercially available electron‐accelerator. Using ZIF‐8 as a representative for demonstration, this type of synthesis can be accomplished under ambient conditions within minutes, leading to energy consumption about two orders of magnitude lower than that of the solvothermal condition. Interestingly, by controlling the absorbed dose in the synthesis, the electron beam not only activates the formation reaction of ZIF‐8, but also partially etches the material during the synthesis affording a hierarchical pore architecture and highly crystalline ZnO nanoparticles on the surface of ZIF‐8. This gives rise to a new strategy to obtain MOF@metal oxide heterostructures, finding utilities in photocatalytic degradation of organic dyes. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are a distinct family of crystalline porous materials finding extensive applications. Their synthesis often requires elevated temperature and relatively long reaction time. We report here the first case of MOF synthesis activated by high‐energy (1.5 MeV) electron beam radiation from a commercially available electron‐accelerator. Using ZIF‐8 as a representative for demonstration, this type of synthesis can be accomplished under ambient conditions within minutes, leading to energy consumption about two orders of magnitude lower than that of the solvothermal condition. Interestingly, by controlling the absorbed dose in the synthesis, the electron beam not only activates the formation reaction of ZIF‐8, but also partially etches the material during the synthesis affording a hierarchical pore architecture and highly crystalline ZnO nanoparticles on the surface of ZIF‐8. This gives rise to a new strategy to obtain MOF@metal oxide heterostructures, finding utilities in photocatalytic degradation of organic dyes. [ABSTRACT FROM AUTHOR]

A rare case of semiconducting actinide-based metal–organic framework SCU-125 was designed and synthesized. As a result of the lack of two coordination sites in the plane of the tetrathiafulvalene tetrabenzoate (TTFTB) molecule, a defective kgd network was formed. The electrical conductivity of SCU-125 was measured to be 2.2(2) × 10−7 S cm−1 at 25 °C ± 2 °C. [ABSTRACT FROM AUTHOR]

A three-dimensional microporous thorium-based metal–organic framework (Th-BPYDC-I) that features a suitable pore size for Xe was prepared. The pore confinement effect enables high Xe uptake (2.15 mmol g−1) and good Xe/Kr selectivity (7.49). This work highlights the critical role of the size-matching rule in noble gas separation and provides an alternative option for Xe/Kr separation. [ABSTRACT FROM AUTHOR]

A novel 3D potassium-containing zirconium fluorophosphonate K2Zr[CH2(PO3)2]F2 (SZ-8) was successfully synthesized as single crystals via a solvothermal method using a mixture of nitric acid and potassium nitrate as mineralizers. SZ-8 can adsorb 110.6 and 57 mg g−1 of Eu3+ in pH 2 and pH 1 solutions respectively, highlighting its potential remediation for radionuclides with high charges. SZ-8 not only possesses superior Eu3+ removal capacity under strongly acidic conditions, but also provides a universal synthesis strategy for crystalline zirconium phosphonates with inorganic counterions. [ABSTRACT FROM AUTHOR]

A novel polymorph of ThB2O5, denoted as β-ThB2O5, was synthesised under high-temperature high-pressure (HT/HP) conditions. Via single crystal X-ray diffraction measurements, β-ThB2O5 was found to form a three-dimensional (3D) framework structure where thorium atoms are ten-fold oxygen coordinated forming tetra-capped trigonal prisms. The only other known polymorph of ThB2O5, denoted α, synthesised herein using a known borax, B2O3–Na2B4O7, high temperature solid method, was found to transform to the β polymorph when exposed to conditions of 4 GPa and ∼900 °C. Compared to the α polymorph, β-ThB2O5 has smaller molar volume by approximately 12%. Exposing a mixture of the α and β polymorphs to HT/HP conditions ex situ further demonstrated the preferred higher-pressure phase being β, with no α phase material being observed via Rietveld refinements against laboratory X-ray powder diffraction (PXRD) measurements. In situ heating PXRD measurements on α-ThB2O5 from RT to 1030 °C indicated that α-ThB2O5 transforms to the β variant at approximately 900 °C via a 1st order mechanism. β-ThB2O5 was found to exist only over a narrow temperature range, decomposing above 1050 °C. Ab initio calculations using density functional theory (DFT) with the Hubbard U parameter indicated, consistent with experimental observations, that β is both the preferred phase at higher temperatures and high pressures. Interestingly, it was found by switching from B2O3–Na2B4O7 to H3BO3–Li2CO3 flux using consistent high temperature solid state conditions for the synthesis of the α variant, β-ThB2O5 could be generated. Comparison of their single crystal measurements showed this was identical to that obtained from HT/HP conditions. [ABSTRACT FROM AUTHOR]

With the extensive usage of gadolinium-based contrast agents (GBCAs) in magnetic resonance imaging (MRI), gadolinium deposition has been observed in the brain, kidneys, liver, etc., and this is also closely related to the development of nephrogenic systemic fibrosis (NSF) in patients with renal dysfunction. Chelation, thereby promoting the elimination of deposited Gd(III), seems to be promising for alleviating these problems. Despite many ligands suitable for chelation therapy having been studied, the decorporation of transition metals (e.g. iron, copper, lead, etc.) and actinides (e.g. uranium, plutonium, etc.) has long been a primary concern, whereas the study of Gd(III) has been extremely limited. Due to their excellent metal binding abilities in vivo and therapeutic effects toward neurodegenerative diseases, bidentate hydroxypyridinone ligands are expected to be able to remove Gd(III) from the brain, kidneys, bones, and liver. Herein, the Gd(III) decorporation efficacy of a bidentate hydroxypyridinone ligand (Me-3,2-HOPO) has been evaluated. The complexation behavior between Me-3,2-HOPO and Gd(III) in solution and solid states was characterized with the assistance of potentiometric titration and X-ray diffraction techniques, respectively. Solution-based thermodynamic studies illustrate that the dominant species of complex between Gd(III) and Me-3,2-HOPO (HL) is GdL2+ (log β120 = 11.8 (3)) at pH 7.4. The structure of the Gd–Me-3,2-HOPO crystal obtained from a room temperature reaction reveals the formation of a Gd(III) dimer that is chelated by four ligands as a result of metal ion hydration and ligand complexation. Cellular Gd(III) removal assays illustrate that Me-3,2-HOPO could effectively reduce final amounts of gadolinium by 77.6% and 66.1% from rat renal proximal tubular epithelial (NRK-52E) cells and alpha mouse liver 12 (AML-12) cells, respectively. Our current results suggest the potential of bidentate HOPO ligands as an effective approach to treat patients suffering from Gd(III) toxicity. [ABSTRACT FROM AUTHOR]

Scintillators display radioluminescent properties when irradiated by high‐energy photons and therefore play an essential role in radiation detection. The current inventory of scintillators is overwhelmingly represented by achiral structures, where the radioluminescence propagates isotropically after generation. Herein, we demonstrate that chiral perovskites of (R‐3AP)PbBr3Cl⋅H2O (R‐3APP) and (S‐3AP)PbBr3Cl⋅H2O (S‐3APP) emerge as a new type of scintillator displaying a distinct property of circularly polarized radioluminescence (CPRL). A high quantum yield of 27.6 %, high luminescence dissymmetric factors (glum) of 4×10−2, and high X‐ray absorption coefficients were observed for these compounds. As proof of concept, we fabricated a polarized scintillator pair by assembling chiral scintillator crystals, which provides a new strategy to attenuate optical crosstalk between the scintillators by precisely controlling the radioluminescence propagation and improves the X‐ray imaging quality at the boundary region. [ABSTRACT FROM AUTHOR]