Search

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]

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]

Comprehensive Summary: We reported the synthesis, single crystal structure, and solid‐state UV‐Vis‐NIR spectroscopy of a new transplutonium metal‐organic framework (MOFs), Am(H2O)[PO[(C6H4)COO]3], denoted as AmTPO (TPO = tris(4‐carboxylphenyl)‐phosphineoxide). AmTPO forms a three‐dimensional metal−organic framework structure with americium dimers as the secondary building unit. Clear 5f → 5f transitions attributed to trivalent americium was observed in the absorption spectrum of AmTPO ranging from 300 to 1200 nm. Notably, AmTPO can maintain the crystallinity with no observable structural degradation within several months after being synthesized, revealing a long‐term radiation resistance of this structure and the potential application of MOFs as a platform for nuclear waste disposal. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Two new uranium(VI) phosphonate compounds, namely K8[N(C2H5)4]2(UO2)17(H2O)4[CH2(PO3)2]8[CH2(PO3)(PO3H)]4‧16(H2O) (1) and [N(C2H5)4]4(H3O)2(UO2)10[CH2(PO3)2]5[CH2(PO3)(PO3H)]2‧10H2O (2), have been synthesized under mild hydro/solvothermal condition. The structural analysis of the two compounds reveals that they both contain all three typical coordination geometries of the U(VI) ions, including UO6 tetragonal, UO7 pentagonal, and UO8 hexagonal bipyramids. Moreover, compound 1 displays a temperature‐induced single crystal to single crystal phase transformation as confirmed by the Single‐crystal X‐ray diffraction data collected at different temperatures. Temperature‐dependent fluorescence spectra presented herein illustrate the perturbation of the electronic structure of uranyl centers. [ABSTRACT FROM AUTHOR]

When exposed to water, the two-dimensional uranyl–organic layered compound [(CH3)2NH2][(UO2)(BCPBA)]·2DMF·H2O (H3BCPBA = 3,5-bis (4′-carboxylphenoxy) benzoic acid) gradually undergoes a complete single-crystal-to-single-crystal phase transition to [(CH3)2NH2][(UO2)(BCPBA)]·3.4H2O, resulting in an enhanced ligand–ligand interaction between the adjacent layers. This process gives rise to initial quenching of the uranyl photoluminescence followed by subsequent recovery of the photoluminescence with a much elevated intensity, as a unique case of aggregation-induced emission in an extended solid system, further confirmed by DFT analysis on bonding. [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]

Under hydrothermal condition, the decomposition of methanesulfonic acid to sulfate anion is observed, resulting in the formation of a novel thorium sulfate fluoride compound ThF 2 (SO 4 )(H 2 O) ( 1 ). This complex is structurally characterized by single crystal X-ray diffraction, revealing a three-dimensional structure crystallized in the monoclinic space-group P 2 1 / n , where thorium cation is nine coordinated by four SO 4 2− oxygen atoms, four bridging F − , and one H 2 O molecule. The crystal lattice parameters are a = 6.9065(7) Å, b = 6.9256(7) Å, c = 10.5892(11) Å, β = 96.755(2)°, V = 502.98(9) Å 3 , Z = 4. The temperature dependent UV–Vis–NIR absorption spectra and fluorescence spectra were collected from 77 K to 300 K, where the intensities of the peaks varied as a function of temperature. The Raman vibrational spectrum of the samples collected from 100 to 2000 cm −1 shows identical SO 4 2− vibration modes. [ABSTRACT FROM AUTHOR]