1344-57-6Relevant academic research and scientific papers
CuS/TiO2 nanotube arrays heterojunction for the photoreduction of uranium (VI)
Cao, Xiaohong,Cheng, Zhongping,Dong, Zhimin,Li, Zifan,Liu, Yuhui,Liu, Yunhai,Wang, Yingcai,Wang, Youqun,Wu, Yongchuan,Zhang, Zhibin,Zheng, Zhijian,Zhu, Xiang
, (2021)
The separation of uranium U(VI) through photoreduction approach has attracted substantial attention. Sulfide-based materials have revealed excellent performance for reducing U(VI) and there is no record of CuS based materials. Herein, we synthesized CuS/T
Synthesis of size-controlled UO2 microspheres from the hydrothermal conversion of U(iv) aspartate
Trillaud,Maynadié,Manaud,Hidalgo,Meyer,Podor,Dacheux,Clavier
, p. 7749 - 7760 (2018)
A simple wet chemistry route towards micrometric spherical UO2 particles was designed through the conversion of uranium(iv) aspartate under mild hydrothermal conditions (T = 160 °C). A multiparametric study examining the effects of hydrothermal
Unexpected Roles of Alkali-Metal Cations in the Assembly of Low-Valent Uranium Sulfate Molecular Complexes
Feng, Mei-Ling,Guo, Xiaofeng,Guo, Xiaojing,Huang, Yu-Ying,Ju, Yu,Lin, Jian,Lin, Xiao,Lin, Yue-Jian,Wang, Jian-Qiang,Yue, Zenghui,Zhang, Zhi-Hui
, (2020)
The directing effect of coordinating ligands in the formation of uranium molecular complexes has been well established, but the role of counterions in metal-ligand interactions remains ambiguous and requires further investigation. In this work, we describe the targeted isolation, through the choice of alkali-metal ions, of a family of tetravalent uranium sulfates, showing the influence of the overall topology and, unexpectedly, the UIV nuclearity upon the inclusion of such countercations. Analyses of the structures of uranium(IV) oxo/hydroxosulfate oligomeric species isolated from consistent synthetic conditions reveal that the incorporation of Na+ and Rb+ promotes the crystallization of 0D discrete clusters with a hexanuclear [U6O4(OH)4(H2O)4]12+ core, whereas the larger Cs+ ion allows for the isolation of a 2D-layered oligomer with a less condensed trinuclear [U3(O)]10+ center. This finding expands the prevalent view that counterions play an innocent role in molecular complex synthesis, affecting only the overall packing but not the local oligomerization. Interestingly, trends in nuclearity appear to correlate with the hydration enthalpies of alkali-metal cations, such that the alkali-metal cations with larger hydration enthalpies correspond to more hydrated complexes and cluster cores. These findings afford new insights into the mechanism of nucleation of UIV, and they also open a new path for the rational design and synthesis of targeted molecular complexes.
Structural Snapshots of Cluster Growth from {U6} to {U38} During the Hydrolysis of UCl4
Chatelain, Lucile,Faizova, Radmila,Fadaei-Tirani, Farzaneh,Pécaut, Jacques,Mazzanti, Marinella
, p. 3021 - 3026 (2019)
Herein we report the assembly of large uranium(IV) clusters with novel nuclearities and/or shapes from the controlled hydrolysis of UCl4 in organic solution and in the presence of the benzoate ligands. {U6}, {U13}, {U16}, {U24}, {U38} oxo and oxo/hydroxo clusters were isolated and crystallographically characterized. These structural snapshots indicate that larger clusters are slowly built from the condensation of octahedral {U6} building blocks. The uranium/benzoate ligand ratio, the reaction temperature and the presence of base play an important role in determining the structure of the final assembly. Moreover, the isolation of different size cluster {U6} (few hours), {U16} (3 days), {U24} (21 days) from the same solution in a chosen set of conditions shows that the assembly of uranium oxo clusters in hydrolytic conditions is time dependent.
Retention of a Paramagnetic Ground State at Low Temperatures in a Family of Structurally Related UIV Phosphates
Felder, Justin B.,Calder, Stuart,Zur Loye, Hans-Conrad
, p. 9286 - 9295 (2018)
A new uranium fluoride phosphate, UFPO4, was synthesized via a mild hydrothermal route and characterized optically, thermally, and magnetically. Two thermal transformation products, U2O(PO4)2 and UIVUVIO2(PO4)2, were discovered to be structurally related, and were subsequently synthesized for bulk property measurements. All three materials failed to follow Curie-Weiss behavior at low temperatures, attributed to the nearly ubiquitous singlet ground state of U(IV), transitioning into a Curie-Weiss paramagnetic regime at high temperatures. Neutron diffraction experiments were performed on UFPO4 and UIVUVIO2(PO4)2 in order to characterize this unusual magnetic behavior.
Use of Microwave Radiation for Denitration of Uranyl Nitrate Solution and Subsequent Sintering of Uranium Dioxide Fuel Pellets
Kulyako, Yu. M.,Myasoedov, B. F.,Perevalov, S. A.,Pilyushenko, K. S.,Savel’ev, B. V.,Trofimov, T. I.,Vinokurov, S. E.
, p. 317 - 322 (2021/06/02)
Abstract: Fabrication of ceramic UO2 fuel pellets using microwave radiation was studied. The UO2 powder was prepared by microwave denitration of a nitric acid solution containing 400 g L–1 uranium. The tapped density (2.39 g cm–3) and total specific surface area (2.70 m2 g–1) of the powder obtained met the requirements to the powder for nuclear fuel fabrication (TU (Technical Specification) 95 414–2005: Uranium Dioxide Powder of Ceramic Grade with the Uranium-235 Isotope Content Lower than 5.0%). Pellets were pressed from the UO2 powder under varied conditions including pressure, its application mode, pressing time, and presence of binder. The pressed pellets were sintered at 1650°С for 2 h in an Ar + 10 vol % H2 atmosphere under the action of microwave radiation. The density of the samples obtained, 10.40 ± 0.02 g cm–3, meets the requirements to ceramic fuel pellets used in thermal reactors.
Chemical Vapor Deposition of Phase-Pure Uranium Dioxide Thin Films from Uranium(IV) Amidate Precursors
Straub, Mark D.,Leduc, Jennifer,Frank, Michael,Raauf, Aida,Lohrey, Trevor D.,Minasian, Stefan G.,Mathur, Sanjay,Arnold, John
, p. 5749 - 5753 (2019/04/16)
Homoleptic uranium(IV) amidate complexes have been synthesized and applied as single-source molecular precursors for the chemical vapor deposition of UO2 thin films. These precursors decompose by alkene elimination to give highly crystalline ph
Silyl-Phosphino-Carbene Complexes of Uranium(IV)
Lu, Erli,Boronski, Josef T.,Gregson, Matthew,Wooles, Ashley J.,Liddle, Stephen T.
supporting information, p. 5506 - 5511 (2018/04/02)
Unprecedented silyl-phosphino-carbene complexes of uranium(IV) are presented, where before all covalent actinide–carbon double bonds were stabilised by phosphorus(V) substituents or restricted to matrix isolation experiments. Conversion of [U(BIPMTMS)(Cl)(μ-Cl)2Li(THF)2] (1, BIPMTMS=C(PPh2NSiMe3)2) into [U(BIPMTMS)(Cl){CH(Ph)(SiMe3)}] (2), and addition of [Li{CH(SiMe3)(PPh2)}(THF)]/Me2NCH2CH2NMe2 (TMEDA) gave [U{C(SiMe3)(PPh2)}(BIPMTMS)(μ-Cl)Li(TMEDA)(μ-TMEDA)0.5]2 (3) by α-hydrogen abstraction. Addition of 2,2,2-cryptand or two equivalents of 4-N,N-dimethylaminopyridine (DMAP) to 3 gave [U{C(SiMe3)(PPh2)}(BIPMTMS)(Cl)][Li(2,2,2-cryptand)] (4) or [U{C(SiMe3)(PPh2)}(BIPMTMS)(DMAP)2] (5). The characterisation data for 3–5 suggest that whilst there is evidence for 3-centre P?C?U π-bonding character, the U=C double bond component is dominant in each case. These U=C bonds are the closest to a true uranium alkylidene yet outside of matrix isolation experiments.
Matrix Infrared Spectra of the Products of Uranium-Atom Reactions with Carbon Monoxide and Carbon Dioxide
Tague, Thomas J.,Andrews, Lester,Hunt, Rodney D.
, p. 10920 - 10924 (2007/10/02)
Uranium atoms from pulsed Nd:YAG laser ablation of a uranium metal target were codeposited with carbon monoxide and carbon dioxide in excess argon at 10 K.Infrared spectra following the U + CO reaction revealed strong new absorption bands at 804.4 and 852.6 cm-1, which are assigned to a CUO product on the basis of isotopic shifts, FG matrix calculations, and ab initio pseudopotential calculations.An absorption at 2027.5 cm-1 is attributed to the asymmetric secondary reaction product CU(O)CO.In both the U + CO and U + CO2 reactions, bands at 870.9 and 1963.8 cm-1 were observed and assigned to the association product of UO2 and CO.Lastly, in the U + CO2 experiments, new absorption band pairs were observed at 804.4 and 1799.6 cm-1 and at 801.5 and 2011.7 cm -1.The former pair was almost destroyed on annealing and is assigned to the OUCO insertion product.The latter pair is attributed to an OCU(O)CO species.The direct reactions of U atoms with CO and CO2 requires an activation energy, which is provided by hyperthermal U atoms from pulsed laser evaporation.
