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Peter C Burns - One of the best experts on this subject based on the ideXlab platform.
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charge density influence on enthalpy of formation of Uranyl peroxide cage cluster salts
Inorganic Chemistry, 2018Co-Authors: Melika Sharifironizi, Jie Qiu, Jennifer E S Szymanowski, Sarah Castillo, Sarah Hickam, Peter C BurnsAbstract:More than 60 unique Uranyl peroxide cage clusters have been reported that contain as many as 124 Uranyl ions and that have overall diameters extending to 4 nm. They self-assemble in water under ambient conditions, are models for understanding structure–size–property relations as well as testing computational models for actinides, and have potential applications in nuclear fuel cycles. High-temperature drop solution calorimetry has been used to derive the enthalpies of formation of the salts of seven topologically diverse Uranyl peroxide cage clusters containing from 22 to 28 Uranyl ions that are bridged by various combinations of peroxide, pyrophosphate, and phosphite. The enthalpies of formation of these seven salts, as well as three salts of other Uranyl peroxide clusters reported earlier, are dominated by the interactions of the alkali countercations with the clusters. There is an approximately linear relationship between the enthalpies of formation of the cluster salts and the charge density of the co...
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Pyrophosphate and Methylenediphosphonate Incorporated Uranyl Peroxide Cage Clusters
2018Co-Authors: Jie Ling, Jie Qiu, Hongxia Zhang, Megan Stoffer, Dawanya Burgess, Peter C BurnsAbstract:Six Uranyl peroxide cage clusters containing 18–54 Uranyl ions, as well as 6–27 pyrophosphate or methylenediphosphonate ligands, have been synthesized and characterized. These Uranyl peroxide clusters self-assemble and crystallize from aqueous solutions containing Uranyl nitrate, hydrogen peroxide, and pyrophosphate or methylenediphosphonate over a pH range from 5.3 to 8.1. In their structures, Uranyl hexagonal bipyramids are linked by bridging peroxide, hydroxide, and pyrophosphate or methylenedisphosphonate ligands. The incorporation of pyrophosphate or methylenedisphosphonate results in several interesting features in the coordination of Uranyl ions and the topology of the Uranyl peroxide clusters
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sulfate centered sodium icosahedron templated Uranyl peroxide phosphate cages with Uranyl bridged by μ η1 η2 peroxide
Inorganic Chemistry, 2017Co-Authors: Jie Qiu, Tyler L Spano, Mateusz Dembowski, Alex M Kokot, Jennifer E S Szymanowski, Peter C BurnsAbstract:Two novel hybrid Uranyl peroxide phosphate cage clusters, designated U20P6 and U20P12, contain peroxide bridges between Uranyl in an unusual μ–η1:η2 configuration, as well as the common μ–η2:η2 configuration. These appear to be the only high-nuclearity metal peroxide complexes containing μ–η1:η2 peroxide bridges, and they are unique among Uranyl peroxide cages. Both clusters contain 20 Uranyl polyhedra, and U20P6 and U20P12 contain 6 and 12 phosphate tetrahedra, respectively. The 20 Uranyl polyhedra in both cages are arranged on the vertices of distorted topological dodecahedrons (20 vertex fullerenes). Each cage is completed by phosphate tetrahedra and is templated by a sulfate-centered Na12 cluster with the Na cations defining a regular convex isocahedron. Whereas μ–η2:η2 peroxides are essential features of Uranyl peroxide cages, where they form equatorial edges of Uranyl hexagonal bipyramids, the μ–η1:η2 peroxide groups in U20P6 and U20P12 are associated with strong distortions of the Uranyl polyhedra....
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time resolved x ray scattering and raman spectroscopic studies of formation of a uranium vanadium phosphorus peroxide cage cluster
Inorganic Chemistry, 2016Co-Authors: Jie Qiu, Mateusz Dembowski, Jennifer E S Szymanowski, Wen Cong Toh, Peter C BurnsAbstract:Combining reactants in water under ambient conditions results in the assembly and crystallization of 2.6 nm diameter cage clusters designated U48V6P48 within 3 weeks. These consist of 24 Uranyl hexagonal bipyramids, 24 Uranyl pentagonal bipyramids, six vanadyl square pyramids, and 48 phosphate tetrahedra. Peroxide-bridged dimers of Uranyl hexagonal bipyramids are linked directly to vanadyl-stabilized tetramers of Uranyl pentagonal bipyramids to form the cage, with phosphate tetrahedra providing additional linkages between these two units. Time-resolved small-angle X-ray scattering and Raman spectroscopy indicate that the combination of the reactants initially resulted in simultaneous formation of smaller Uranyl peroxide cages and vanadyl peroxide complexes. The disappearance of the smaller Uranyl peroxide cages from solution coincides with the diminution of uncoordinated peroxide, both of which occurred before the assembly of the relatively peroxide-poor U48V6P48, which clearly occurred in solution prior ...
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Incorporation of Np(V) and U(VI) in carbonate and sulfate minerals crystallized from aqueous solution
Geochimica et Cosmochimica Acta, 2015Co-Authors: Enrica Balboni, Zheming Wang, Jessica M. Morrison, Mark H. Engelhard, Peter C BurnsAbstract:Abstract The neptunyl Np(V)O2+ and Uranyl U(VI)O22+ ions are soluble in groundwater, although their interaction with minerals in the subsurface may impact their mobility. One mechanism for the immobilization of actinyl ions in the subsurface is co-precipitation in low-temperature minerals that form naturally, or that are induced to form as part of a remediation strategy. Important differences in the crystal-chemical behavior of the Np(V) neptunyl and U(VI) Uranyl ions suggest their behavior towards incorporation into growing crystals may differ significantly. Using a selection of low-temperature minerals synthesized in aqueous systems under ambient conditions, this study examines the factors that impact the structural incorporation of the Np(V) neptunyl and U(VI) Uranyl ions in carbonate and sulfate minerals. Calcite (CaCO3), aragonite (CaCO3), gypsum (CaSO4·2H2O), strontianite (SrCO3), cerussite (PbCO3), celestine (SrSO4), and anglesite (PbSO4) were synthesized from aqueous solutions containing either 400–1000 ppm of U(VI) or Np(V) relative to the divalent cation present in the system. The synthetic products were investigated by inductively coupled plasma mass spectrometry, luminescence and time resolved luminescence spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Amongst the carbonate minerals, calcite significantly favors Np(V) incorporation over U(VI). U(VI) and Np(V) are incorporated in aragonite and strontianite in similar amounts, whereas cerussite did not incorporate either U(VI) or Np(V) under the synthesis conditions. The sulfate minerals weakly interact with the actinyl ions, relative to the carbonate minerals. Incorporation of U(VI) and Np(V) in celestine was observed at the level of a few tens of ppm; anglesite and gypsum did not incorporate detectable U(VI) or Np(V). Luminescence spectra of the Uranyl incorporated in aragonite and strontianite are consistent with a Uranyl unit coordinated by three bidentate CO32− groups. The time-resolved spectra of calcite indicate multiple coordination environments about the Uranyl unit, with the spectra of the longer-lived components displaying similarities with Uranyl-incorporated aragonite. The luminescence spectrum of Uranyl-bearing celestine is consistent with a Uranyl unit coordinated by monodentate sulfate groups. Anglesite synthesized in the presence of Uranyl shows no luminescence, whereas the spectra of gypsum and cerussite suggest Uranyl surface adsorption or precipitation of secondary Uranyl minerals on the mineral surfaces. Our findings indicate that geometrical constraints of the Np(V) and U(VI) species in solution, together with the crystallographic steric constraints of the host material, affect preferential uptake in the mineral structures studied. Calcium and strontium appear to be favorable incorporation sites for both U(VI) and Np(V) in aragonite and strontianite. In calcite, Np(V) incorporation is strongly favored over U(VI), whereas in gypsum incorporation of neither actinyl ion occurs. Substitution of actinyl ions was also not observed for lead, in either the carbonate or sulfate minerals studied.
Jason B Love - One of the best experts on this subject based on the ideXlab platform.
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control of oxo group functionalization and reduction of the Uranyl ion
Inorganic Chemistry, 2015Co-Authors: Polly L Arnold, Annefrederique Pecharman, Rianne M Lord, Guy M Jones, Emmalina Hollis, Gary S Nichol, Laurent Maron, Jian Fang, Thomas Davin, Jason B LoveAbstract:Uranyl complexes of a large, compartmental N8-macrocycle adopt a rigid, “Pacman” geometry that stabilizes the UV oxidation state and promotes chemistry at a single Uranyl oxo-group. We present here new and straightforward routes to singly reduced and oxo-silylated Uranyl Pacman complexes and propose mechanisms that account for the product formation, and the byproduct distributions that are formed using alternative reagents. Uranyl(VI) Pacman complexes in which one oxo-group is functionalized by a single metal cation are activated toward single-electron reduction. As such, the addition of a second equivalent of a Lewis acidic metal complex such as MgN″2 (N″ = N(SiMe3)2) forms a Uranyl(V) complex in which both oxo-groups are Mg functionalized as a result of Mg–N bond homolysis. In contrast, reactions with the less Lewis acidic complex [Zn(N″)Cl] favor the formation of weaker U–O–Zn dative interactions, leading to reductive silylation of the Uranyl oxo-group in preference to metalation. Spectroscopic, crysta...
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oxo functionalization and reduction of the Uranyl ion through lanthanide element bond homolysis synthetic structural and bonding analysis of a series of singly reduced Uranyl rare earth 5f1 4fn complexes
Journal of the American Chemical Society, 2013Co-Authors: Polly L Arnold, Jason B Love, Emmalina Hollis, Gary S Nichol, Laurent Maron, N Magnani, Jean Christophe Griveau, R Caciuffo, Ludovic CastroAbstract:The heterobimetallic complexes [{UO2Ln(py)2(L)}2], combining a singly reduced Uranyl cation and a rare-earth trication in a binucleating polypyrrole Schiff-base macrocycle (Pacman) and bridged through a Uranyl oxo-group, have been prepared for Ln = Sc, Y, Ce, Sm, Eu, Gd, Dy, Er, Yb, and Lu. These compounds are formed by the single-electron reduction of the Pacman Uranyl complex [UO2(py)(H2L)] by the rare-earth complexes LnIII(A)3 (A = N(SiMe3)2, OC6H3But2-2,6) via homolysis of a Ln–A bond. The complexes are dimeric through mutual Uranyl exo-oxo coordination but can be cleaved to form the trimetallic, monoUranyl “ate” complexes [(py)3LiOUO(μ-X)Ln(py)(L)] by the addition of lithium halides. X-ray crystallographic structural characterization of many examples reveals very similar features for monomeric and dimeric series, the dimers containing an asymmetric U2O2 diamond core with shorter Uranyl U═O distances than in the monomeric complexes. The synthesis by LnIII–A homolysis allows [5f1-4fn]2 and Li[5f1-4fn] ...
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reduction and selective oxo group silylation of the Uranyl dication
Nature, 2008Co-Authors: Polly L Arnold, Dipti Patel, Claire Wilson, Jason B LoveAbstract:Uranium is present almost everywhere in the environment as the highly soluble and mobile Uranyl dication UO22+, which is also a major radioactive pollutant from the nuclear power and mining industries. The compound is chemically inert because of unusually strong bonds between the uranium atom and its two oxo groups. Arnold et al. now report that one Uranyl oxo group can be made to undergo radical reactions normally associated only with transition metal oxo groups, if the strong O=U=O bonding is disrupted by placing the dication within an appropriate rigid molecular framework. Once put in the spot, the Uranyl dication undergoes both single-electron reduction and oxo-group functionalization to form unique pentavalent Uranyl compounds. These transformations might lead to strategies for manipulating and processing uranium in its most common form in solution. Uranium occurs in the environment predominantly as the Uranyl dication [UO2]2+. Its solubility renders this species a problematic contaminant1,2,3 which is, moreover, chemically extraordinarily robust owing to strongly covalent U–O bonds4. This feature manifests itself in the Uranyl dication showing little propensity to partake in the many oxo group functionalizations and redox reactions typically seen with [CrO2]2+, [MoO2]2+ and other transition metal analogues5,6,7,8,9. As a result, only a few examples of [UO2]2+ with functionalized oxo groups are known. Similarly, it is only very recently that the isolation and characterization of the singly reduced, pentavalent Uranyl cation [UO2]+ has been reported10,11,12. Here we show that placing the Uranyl dication within a rigid and well-defined molecular framework while keeping the environment anaerobic allows simultaneous single-electron reduction and selective covalent bond formation at one of the two Uranyl oxo groups. The product of this reaction is a pentavalent and monofunctionalized [O = U ... OR]+ cation that can be isolated in the presence of transition metal cations. This finding demonstrates that under appropriate reaction conditions, the Uranyl oxo group will readily undergo radical reactions commonly associated only with transition metal oxo groups. We expect that this work might also prove useful in probing the chemistry of the related but highly radioactive plutonyl and neptunyl analogues found in nuclear waste.
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reduction and selective oxo group silylation of the Uranyl dication
Nature, 2008Co-Authors: Polly L Arnold, Dipti Patel, Claire Wilson, Jason B LoveAbstract:Uranium occurs in the environment predominantly as the Uranyl dication [UO2]2+. Its solubility renders this species a problematic contaminant which is, moreover, chemically extraordinarily robust owing to strongly covalent U-O bonds. This feature manifests itself in the Uranyl dication showing little propensity to partake in the many oxo group functionalizations and redox reactions typically seen with [CrO2]2+, [MoO2]2+ and other transition metal analogues. As a result, only a few examples of [UO2]2+ with functionalized oxo groups are known. Similarly, it is only very recently that the isolation and characterization of the singly reduced, pentavalent Uranyl cation [UO2]+ has been reported. Here we show that placing the Uranyl dication within a rigid and well-defined molecular framework while keeping the environment anaerobic allows simultaneous single-electron reduction and selective covalent bond formation at one of the two Uranyl oxo groups. The product of this reaction is a pentavalent and monofunctionalized [O = U...OR]+ cation that can be isolated in the presence of transition metal cations. This finding demonstrates that under appropriate reaction conditions, the Uranyl oxo group will readily undergo radical reactions commonly associated only with transition metal oxo groups. We expect that this work might also prove useful in probing the chemistry of the related but highly radioactive plutonyl and neptunyl analogues found in nuclear waste.
Polly L Arnold - One of the best experts on this subject based on the ideXlab platform.
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control of oxo group functionalization and reduction of the Uranyl ion
Inorganic Chemistry, 2015Co-Authors: Polly L Arnold, Annefrederique Pecharman, Rianne M Lord, Guy M Jones, Emmalina Hollis, Gary S Nichol, Laurent Maron, Jian Fang, Thomas Davin, Jason B LoveAbstract:Uranyl complexes of a large, compartmental N8-macrocycle adopt a rigid, “Pacman” geometry that stabilizes the UV oxidation state and promotes chemistry at a single Uranyl oxo-group. We present here new and straightforward routes to singly reduced and oxo-silylated Uranyl Pacman complexes and propose mechanisms that account for the product formation, and the byproduct distributions that are formed using alternative reagents. Uranyl(VI) Pacman complexes in which one oxo-group is functionalized by a single metal cation are activated toward single-electron reduction. As such, the addition of a second equivalent of a Lewis acidic metal complex such as MgN″2 (N″ = N(SiMe3)2) forms a Uranyl(V) complex in which both oxo-groups are Mg functionalized as a result of Mg–N bond homolysis. In contrast, reactions with the less Lewis acidic complex [Zn(N″)Cl] favor the formation of weaker U–O–Zn dative interactions, leading to reductive silylation of the Uranyl oxo-group in preference to metalation. Spectroscopic, crysta...
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oxo functionalization and reduction of the Uranyl ion through lanthanide element bond homolysis synthetic structural and bonding analysis of a series of singly reduced Uranyl rare earth 5f1 4fn complexes
Journal of the American Chemical Society, 2013Co-Authors: Polly L Arnold, Jason B Love, Emmalina Hollis, Gary S Nichol, Laurent Maron, N Magnani, Jean Christophe Griveau, R Caciuffo, Ludovic CastroAbstract:The heterobimetallic complexes [{UO2Ln(py)2(L)}2], combining a singly reduced Uranyl cation and a rare-earth trication in a binucleating polypyrrole Schiff-base macrocycle (Pacman) and bridged through a Uranyl oxo-group, have been prepared for Ln = Sc, Y, Ce, Sm, Eu, Gd, Dy, Er, Yb, and Lu. These compounds are formed by the single-electron reduction of the Pacman Uranyl complex [UO2(py)(H2L)] by the rare-earth complexes LnIII(A)3 (A = N(SiMe3)2, OC6H3But2-2,6) via homolysis of a Ln–A bond. The complexes are dimeric through mutual Uranyl exo-oxo coordination but can be cleaved to form the trimetallic, monoUranyl “ate” complexes [(py)3LiOUO(μ-X)Ln(py)(L)] by the addition of lithium halides. X-ray crystallographic structural characterization of many examples reveals very similar features for monomeric and dimeric series, the dimers containing an asymmetric U2O2 diamond core with shorter Uranyl U═O distances than in the monomeric complexes. The synthesis by LnIII–A homolysis allows [5f1-4fn]2 and Li[5f1-4fn] ...
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reduction and selective oxo group silylation of the Uranyl dication
Nature, 2008Co-Authors: Polly L Arnold, Dipti Patel, Claire Wilson, Jason B LoveAbstract:Uranium is present almost everywhere in the environment as the highly soluble and mobile Uranyl dication UO22+, which is also a major radioactive pollutant from the nuclear power and mining industries. The compound is chemically inert because of unusually strong bonds between the uranium atom and its two oxo groups. Arnold et al. now report that one Uranyl oxo group can be made to undergo radical reactions normally associated only with transition metal oxo groups, if the strong O=U=O bonding is disrupted by placing the dication within an appropriate rigid molecular framework. Once put in the spot, the Uranyl dication undergoes both single-electron reduction and oxo-group functionalization to form unique pentavalent Uranyl compounds. These transformations might lead to strategies for manipulating and processing uranium in its most common form in solution. Uranium occurs in the environment predominantly as the Uranyl dication [UO2]2+. Its solubility renders this species a problematic contaminant1,2,3 which is, moreover, chemically extraordinarily robust owing to strongly covalent U–O bonds4. This feature manifests itself in the Uranyl dication showing little propensity to partake in the many oxo group functionalizations and redox reactions typically seen with [CrO2]2+, [MoO2]2+ and other transition metal analogues5,6,7,8,9. As a result, only a few examples of [UO2]2+ with functionalized oxo groups are known. Similarly, it is only very recently that the isolation and characterization of the singly reduced, pentavalent Uranyl cation [UO2]+ has been reported10,11,12. Here we show that placing the Uranyl dication within a rigid and well-defined molecular framework while keeping the environment anaerobic allows simultaneous single-electron reduction and selective covalent bond formation at one of the two Uranyl oxo groups. The product of this reaction is a pentavalent and monofunctionalized [O = U ... OR]+ cation that can be isolated in the presence of transition metal cations. This finding demonstrates that under appropriate reaction conditions, the Uranyl oxo group will readily undergo radical reactions commonly associated only with transition metal oxo groups. We expect that this work might also prove useful in probing the chemistry of the related but highly radioactive plutonyl and neptunyl analogues found in nuclear waste.
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reduction and selective oxo group silylation of the Uranyl dication
Nature, 2008Co-Authors: Polly L Arnold, Dipti Patel, Claire Wilson, Jason B LoveAbstract:Uranium occurs in the environment predominantly as the Uranyl dication [UO2]2+. Its solubility renders this species a problematic contaminant which is, moreover, chemically extraordinarily robust owing to strongly covalent U-O bonds. This feature manifests itself in the Uranyl dication showing little propensity to partake in the many oxo group functionalizations and redox reactions typically seen with [CrO2]2+, [MoO2]2+ and other transition metal analogues. As a result, only a few examples of [UO2]2+ with functionalized oxo groups are known. Similarly, it is only very recently that the isolation and characterization of the singly reduced, pentavalent Uranyl cation [UO2]+ has been reported. Here we show that placing the Uranyl dication within a rigid and well-defined molecular framework while keeping the environment anaerobic allows simultaneous single-electron reduction and selective covalent bond formation at one of the two Uranyl oxo groups. The product of this reaction is a pentavalent and monofunctionalized [O = U...OR]+ cation that can be isolated in the presence of transition metal cations. This finding demonstrates that under appropriate reaction conditions, the Uranyl oxo group will readily undergo radical reactions commonly associated only with transition metal oxo groups. We expect that this work might also prove useful in probing the chemistry of the related but highly radioactive plutonyl and neptunyl analogues found in nuclear waste.
Jie Qiu - One of the best experts on this subject based on the ideXlab platform.
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charge density influence on enthalpy of formation of Uranyl peroxide cage cluster salts
Inorganic Chemistry, 2018Co-Authors: Melika Sharifironizi, Jie Qiu, Jennifer E S Szymanowski, Sarah Castillo, Sarah Hickam, Peter C BurnsAbstract:More than 60 unique Uranyl peroxide cage clusters have been reported that contain as many as 124 Uranyl ions and that have overall diameters extending to 4 nm. They self-assemble in water under ambient conditions, are models for understanding structure–size–property relations as well as testing computational models for actinides, and have potential applications in nuclear fuel cycles. High-temperature drop solution calorimetry has been used to derive the enthalpies of formation of the salts of seven topologically diverse Uranyl peroxide cage clusters containing from 22 to 28 Uranyl ions that are bridged by various combinations of peroxide, pyrophosphate, and phosphite. The enthalpies of formation of these seven salts, as well as three salts of other Uranyl peroxide clusters reported earlier, are dominated by the interactions of the alkali countercations with the clusters. There is an approximately linear relationship between the enthalpies of formation of the cluster salts and the charge density of the co...
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Pyrophosphate and Methylenediphosphonate Incorporated Uranyl Peroxide Cage Clusters
2018Co-Authors: Jie Ling, Jie Qiu, Hongxia Zhang, Megan Stoffer, Dawanya Burgess, Peter C BurnsAbstract:Six Uranyl peroxide cage clusters containing 18–54 Uranyl ions, as well as 6–27 pyrophosphate or methylenediphosphonate ligands, have been synthesized and characterized. These Uranyl peroxide clusters self-assemble and crystallize from aqueous solutions containing Uranyl nitrate, hydrogen peroxide, and pyrophosphate or methylenediphosphonate over a pH range from 5.3 to 8.1. In their structures, Uranyl hexagonal bipyramids are linked by bridging peroxide, hydroxide, and pyrophosphate or methylenedisphosphonate ligands. The incorporation of pyrophosphate or methylenedisphosphonate results in several interesting features in the coordination of Uranyl ions and the topology of the Uranyl peroxide clusters
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sulfate centered sodium icosahedron templated Uranyl peroxide phosphate cages with Uranyl bridged by μ η1 η2 peroxide
Inorganic Chemistry, 2017Co-Authors: Jie Qiu, Tyler L Spano, Mateusz Dembowski, Alex M Kokot, Jennifer E S Szymanowski, Peter C BurnsAbstract:Two novel hybrid Uranyl peroxide phosphate cage clusters, designated U20P6 and U20P12, contain peroxide bridges between Uranyl in an unusual μ–η1:η2 configuration, as well as the common μ–η2:η2 configuration. These appear to be the only high-nuclearity metal peroxide complexes containing μ–η1:η2 peroxide bridges, and they are unique among Uranyl peroxide cages. Both clusters contain 20 Uranyl polyhedra, and U20P6 and U20P12 contain 6 and 12 phosphate tetrahedra, respectively. The 20 Uranyl polyhedra in both cages are arranged on the vertices of distorted topological dodecahedrons (20 vertex fullerenes). Each cage is completed by phosphate tetrahedra and is templated by a sulfate-centered Na12 cluster with the Na cations defining a regular convex isocahedron. Whereas μ–η2:η2 peroxides are essential features of Uranyl peroxide cages, where they form equatorial edges of Uranyl hexagonal bipyramids, the μ–η1:η2 peroxide groups in U20P6 and U20P12 are associated with strong distortions of the Uranyl polyhedra....
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time resolved x ray scattering and raman spectroscopic studies of formation of a uranium vanadium phosphorus peroxide cage cluster
Inorganic Chemistry, 2016Co-Authors: Jie Qiu, Mateusz Dembowski, Jennifer E S Szymanowski, Wen Cong Toh, Peter C BurnsAbstract:Combining reactants in water under ambient conditions results in the assembly and crystallization of 2.6 nm diameter cage clusters designated U48V6P48 within 3 weeks. These consist of 24 Uranyl hexagonal bipyramids, 24 Uranyl pentagonal bipyramids, six vanadyl square pyramids, and 48 phosphate tetrahedra. Peroxide-bridged dimers of Uranyl hexagonal bipyramids are linked directly to vanadyl-stabilized tetramers of Uranyl pentagonal bipyramids to form the cage, with phosphate tetrahedra providing additional linkages between these two units. Time-resolved small-angle X-ray scattering and Raman spectroscopy indicate that the combination of the reactants initially resulted in simultaneous formation of smaller Uranyl peroxide cages and vanadyl peroxide complexes. The disappearance of the smaller Uranyl peroxide cages from solution coincides with the diminution of uncoordinated peroxide, both of which occurred before the assembly of the relatively peroxide-poor U48V6P48, which clearly occurred in solution prior ...
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hybrid uranium transition metal oxide cage clusters
Inorganic Chemistry, 2014Co-Authors: Jie Ling, Franklin Hobbs, Steven Prendergast, Pius O Adelani, Jeanmarie Babo, Jie Qiu, Zhehui Weng, Peter C BurnsAbstract:Transition-metal based polyoxometalate clusters have been known for decades, whereas those built from Uranyl peroxide polyhedra have more recently emerged as a family of complex clusters. Here we report the synthesis and structures of six nanoscale Uranyl peroxide cage clusters that contain either tungstate or molybdate polyhedra as part of the cage, as well as phosphate tetrahedra. These transition-metal–uranium hybrid clusters exhibit unique polyhedral connectivities and topologies that include 6-, 7-, 8-, 10-, and 12-membered rings of Uranyl polyhedra and Uranyl ions coordinated by bidentate peroxide in both trans and cis configurations. The transition-metal polyhedra appear to stabilize unusual units built of Uranyl polyhedra, rather than templating their formation.
Xiaomei Wang - One of the best experts on this subject based on the ideXlab platform.
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3 hydroxy 2 pyrrolidinone as a potential bidentate ligand for in vivo chelation of Uranyl with low cytotoxicity and moderate decorporation efficacy a solution thermodynamics structural chemistry and in vivo Uranyl removal survey
Inorganic Chemistry, 2019Co-Authors: Xiaomei Wang, Suqiang Wu, Jingwen Guan, Lanhua Chen, Cen Shi, Jianmei Wan, Yong Liu, Juan Diwu, Jianqiang WangAbstract:Uranium poses a threat for severe renal and bone damage in vivo. With the rapid development of nuclear industry, it is more urgent than ever to search for potential in vivo uranium chelators. In this work, 3-hydroxy-2-pyrrolidinone (HPD) is investigated as a new potential uranium decorporation ligand. The potentiometric titration measurements were carried out, and the stability constants were determined to be log β110 = 10.5(7), log β120 = 20.7(9), and log β130 = 28.2(4). The species distribution diagram shows that nearly all Uranyl is complexed by HPD at pH 7.4 under the defined condition. A single crystal of Uranyl and HPD complexes, [(UO2)3O(H2O)3(C4H6NO2)3]·NO3·12H2O (Uranyl-HPD), was obtained via an evaporation method. The overall structure of Uranyl-HPD is a trimer that consists of three Uranyl units and three HPD ligands. The Uranyl unit is equatorially coordinated by three oxygen atoms from two HPD agents, one coordinated water molecule, and one μ3-O atom that is shared by three Uranyl units. The ...
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3‑Hydroxy-2-Pyrrolidinone as a Potential Bidentate Ligand for in Vivo Chelation of Uranyl with Low Cytotoxicity and Moderate Decorporation Efficacy: A Solution Thermodynamics, Structural Chemistry, and in Vivo Uranyl Removal Survey
2019Co-Authors: Xiaomei Wang, Jingwen Guan, Lanhua Chen, Cen Shi, Jianmei Wan, Yong Liu, Juan Diwu, Jianqiang Wang, Shuao WangAbstract:Uranium poses a threat for severe renal and bone damage in vivo. With the rapid development of nuclear industry, it is more urgent than ever to search for potential in vivo uranium chelators. In this work, 3-hydroxy-2-pyrrolidinone (HPD) is investigated as a new potential uranium decorporation ligand. The potentiometric titration measurements were carried out, and the stability constants were determined to be log β110 = 10.5(7), log β120 = 20.7(9), and log β130 = 28.2(4). The species distribution diagram shows that nearly all Uranyl is complexed by HPD at pH 7.4 under the defined condition. A single crystal of Uranyl and HPD complexes, [(UO2)3O(H2O)3(C4H6NO2)3]·NO3·12H2O (Uranyl-HPD), was obtained via an evaporation method. The overall structure of Uranyl-HPD is a trimer that consists of three Uranyl units and three HPD ligands. The Uranyl unit is equatorially coordinated by three oxygen atoms from two HPD agents, one coordinated water molecule, and one μ3-O atom that is shared by three Uranyl units. The results of the cytotoxicity assay indicate that the ligand is less toxic than the chelators used clinically (i.e., DTPA-ZnNa3 and 3-hydroxy-1,2-dimethyl-4(1H)-pyridone (DFP)). The results of the uranium removal assay using the NRK-52E cell show that it could reduce as much as 58% of the uranium content at the cellular level. Furthermore, the in vivo uranium decorporation assays demonstrate that HPD can remove 52% of uranium deposited in the kidney but shows poor uranium removal efficacy in the bone
