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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]

Comprehensive Summary: The environmental contamination of uranium will occur in scenarios such as nuclear accidents and leakage from nuclear waste storage sites, which eventually leads to the internal uranium exposure of people, causing consequential injuries of renal failure, osteosarcoma, etc. The development of uranyl specific chelating agents that could sequester uranium in vivo is in urgent need and is important for the safe and efficient development of nuclear industry. Metal organic frameworks (MOFs) already serve as efficient uranium depletion materials in solutions of a wide range of pH and ionic strength for nuclear fuel recycling, uranium extraction from seawater, as well as environmental decontamination. Herein, a chromium‐based nano‐metal organic framework (nano‐MOF) functionalized interiorly with 3,2‐HOPO ligands, MIL‐101‐HOPO, is rationally synthesized. In vitro adsorption experiments show that MIL‐101‐HOPO exhibits high adsorption selectivity and fast adsorption kinetics for uranyl. The results of in vivo uranyl decorporation assays reveal that MIL‐101‐HOPO with the decoration of HOPO ligands on the interior wall exhibits significantly increased uranyl removal ratio in kidneys comparing to the pristine nMOFs, and is more effective than the clinically used ZnNa3‐DTPA. All those results corroborate the interior functionalization of MOFs as an efficient strategy to develop promising uranyl decorporation agents. [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]

Summary of main observation and conclusion: We present a new method for generating europium oxalate compounds by decomposing of N‐methyl 2‐pyrrolidone in HNO3 media. The reaction exhibits high selectivity towards Eu3+ over UO22+, which suggests that these conditions could be applied to a selective crystallization based separation system for trivalent lanthanides and hexavalent actinides. In this work, a new method for the separation of trivalent Eu3+ and hexavalent UO22+ in initial high‐acidity HNO3 solution is presented. N‐Methyl 2‐pyrrolidone was added in the HNO3 solution where Eu3+ and UO22+ coexisted, then the solution was heated. Eu3+ will react with oxalic acid and dimethylamine produced by N‐methyl 2‐pyrrolidone and form compound NH2(CH3)2[Eu(C2O4)2(H2O)], while UO22+ remains in the solution. This method provide a new strategy for separation of trivalent Eu3+ and hexavalent UO22+. [ABSTRACT FROM AUTHOR]