Showing papers on "Uranyl published in 2014"
TL;DR: In this article, a comprehensive review of the crystal structures resulting from the different types of complexation of uranium with carboxylic acid molecules (excepting oxalate ligand) and their classification as a function of the nuclearity of identified building units is presented.
331 citations
TL;DR: The design and rational development of a uranyl-binding protein is reported using a computational screening process in the initial search for potential uranyl -binding sites, which offers very high affinity and selectivity for uranyl and can repeatedly sequester 30-60% of the uranyl in synthetic sea water.
Abstract: The extraction of uranium from seawater is limited by the high concentrations of carbonate and competing metal ions. Now, a highly selective uranyl-binding protein with femtomolar affinity has been developed. This protein can extract up to 60% uranium from synthetic seawater when immobilized on bacterial cell surfaces or amylose resin.
252 citations
TL;DR: The Schiff base and its metal complexes were evaluated for antimicrobial activity against Gram positive bacteria (Staphylococcus aureus), Gram negative bacteria (Escherichia coli) and fungi (Candida albicans and Aspergillus flavus) and the ligand and some of its complexes were found to be biologically active.
121 citations
TL;DR: The results of this study both provide a new mechanistic understanding of uranium incorporation into hematite and define the nature of the bonding environment of uranium within the mineral structure.
Abstract: Ferrihydrite was exposed to U(VI)-containing cement leachate (pH 10.5) and aged to induce crystallization of hematite. A combination of chemical extractions, TEM, and XAS techniques provided the first evidence that adsorbed U(VI) (≈3000 ppm) was incorporated into hematite during ferrihydrite aggregation and the early stages of crystallization, with continued uptake occurring during hematite ripening. Analysis of EXAFS and XANES data indicated that the U(VI) was incorporated into a distorted, octahedrally coordinated site replacing Fe(III). Fitting of the EXAFS showed the uranyl bonds lengthened from 1.81 to 1.87 A, in contrast to previous studies that have suggested that the uranyl bond is lost altogether upon incorporation into hematite. The results of this study both provide a new mechanistic understanding of uranium incorporation into hematite and define the nature of the bonding environment of uranium within the mineral structure. Immobilization of U(VI) by incorporation into hematite has clear and im...
120 citations
TL;DR: This study optimized 22 complexes between uranyl ion and GO applying density functional theory (DFT) combined with quasi-relativistic small-core pseudopotentials to provide insights for designing new nanomaterials that can efficiently remove radionuclides from radioactive wastewater.
Abstract: Studying the bonding nature of uranyl ion and graphene oxide (GO) is very important for understanding the mechanism of the removal of uranium from radioactive wastewater with GO-based materials. We have optimized 22 complexes between uranyl ion and GO applying density functional theory (DFT) combined with quasi-relativistic small-core pseudopotentials. The studied oxygen-containing functional groups include hydroxyl, carboxyl, amido, and dimethylformamide. It is observed that the distances between uranium atoms and oxygen atoms of GO (U–OG) are shorter in the anionic GO complexes (uranyl/GO–/2–) compared to the neutral GO ones (uranyl/GO). The formation of hydrogen bonds in the uranyl/GO–/2– complexes can enhance the binding ability of anionic GO toward uranyl ions. Furthermore, the thermodynamic calculations show that the changes of the Gibbs free energies in solution are relatively more negative for complexation reactions concerning the hydroxyl and carboxyl functionalized anionic GO complexes. Therefor...
92 citations
TL;DR: Kinetic analysis of the model displacement reaction confirms the rate-determining step in the extraction process, that is, the complexing of uranyl by amidoxime group coupled with the dissociation of the carbonate group from the uranyl tricarbonate complex [UO2(CO3)3](4-).
Abstract: Recovery of uranium from seawater is extremely challenging but important for the persistent development of nuclear energy, and thus exploring the coordination structures and bonding nature of uranyl complexes becomes essential for designing highly efficient uranium adsorbents. In this work, the interactions of uranium and a series of adsorbents with various well-known functional groups including amidoximate (AO–), carboxyl (Ac–), glutarimidedioximate (HA–), and bifunctional AO–/Ac–, HA–/Ac– on different alkyl chains (R′═CH3, R″═C13H26) were systematically studied by quantum chemical calculations. For all the uranyl complexes, the monodentate and η2 coordination are the main binding modes for the AO– groups, while Ac– groups act as monodentate and bidentate ligands. Amidoximes can also form cyclic imide dioximes (H2A), which coordinate to UO22+ as tridentate ligands. Kinetic analysis of the model displacement reaction confirms the rate-determining step in the extraction process, that is, the complexing of ...
90 citations
TL;DR: The uranium(VI) carbene imido oxo complex exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups.
Abstract: We report the uranium(VI) carbene imido oxo complex [U(BIPMTMS)(NMes)(O)(DMAP)2] (5, BIPMTMS=C(PPh2NSiMe3)2; Mes=2,4,6-Me3C6H2; DMAP=4-(dimethylamino)pyridine) which exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups. This complex was prepared by incorporation of carbene, imido, and then oxo groups at the uranium center by salt elimination, protonolysis, and two-electron oxidation, respectively. The oxo and imido groups adopt axial positions in a T-shaped motif with respect to the carbene, which is consistent with an inverse trans-influence. Complex 5 reacts with tert-butylisocyanate at the imido rather than carbene group to afford the uranyl(VI) carbene complex [U(BIPMTMS)(O)2(DMAP)2] (6).
90 citations
TL;DR: The synthesis, the structure, and the magnetic characterization of the first actinide-containing SCM are reported, probably as a result of strong intra-chain magnetic interactions combined with the high Ising anisotropy of the uranyl(V) dioxo group.
Abstract: Single-chain magnets (SCMs) are materials composed of magnetically isolated one-dimensional (1D) units exhibiting slow relaxation of magnetization. The occurrence of SCM behavior requires the fulfillment of stringent conditions for exchange and anisotropy interactions. Herein, we report the synthesis, the structure, and the magnetic characterization of the first actinide-containing SCM. The 5f–3d heterometallic 1D chains [{[UO2(salen)(py)][M(py)4](NO3)}]n, (M=Cd (1) and M=Mn (2); py=pyridine) are assembled trough cation–cation interaction from the reaction of the uranyl(V) complex [UO2(salen)py][Cp*2Co] (Cp*=pentamethylcyclopentadienyl) with Cd(NO3)2 or Mn(NO3)2 in pyridine. The infinite UMn chain displays a high relaxation barrier of 134±0.8 K (93±0.5 cm−1), probably as a result of strong intra-chain magnetic interactions combined with the high Ising anisotropy of the uranyl(V) dioxo group. It also exhibits an open magnetic hysteresis loop at T<6 K, with an impressive coercive field of 3.4 T at 2 K.
86 citations
TL;DR: The results of characterization and analysis show that after addition of glyoxal into only bayberry tannin-based hydrothermal reaction system, the as-synthesized HTC-btg displayed higher thermal stability, larger specific surface area and more than doubled surface phenolic hydroxyl groups.
83 citations
TL;DR: The selectivity studies revealed that the ion-imprinted microspheres resin exhibited an obvious affinity toward the uranyl ions in presence of other interfering metal ions compared to the non-imprint resin.
81 citations
TL;DR: The results of free-energy simulations confirmed the previously reported experimental results and allowed us to discover a mutant of SUP, specifically the GLU64ASP mutant, that not only binds UO2(2+) more strongly than SUP but that is also more selective for UO 2( 2+) over other ions.
Abstract: The capture of uranyl, UO22+, by a recently engineered protein (Zhou et al. Nat. Chem. 2014, 6, 236) with high selectivity and femtomolar sensitivity has been examined by a combination of density functional theory, molecular dynamics, and free-energy simulations. It was found that UO22+ is coordinated to five carboxylate oxygen atoms from four amino acid residues of the super uranyl binding protein (SUP). A network of hydrogen bonds between the amino acid residues coordinated to UO22+ and residues in its second coordination sphere also affects the protein’s uranyl binding affinity. Free-energy simulations show how UO22+ capture is governed by the nature of the amino acid residues in the binding site, the integrity and strength of the second-sphere hydrogen bond network, and the number of water molecules in the first coordination sphere. Alteration of any of these three factors through mutations generally results in a reduction of the binding free energy of UO22+ to the aqueous protein as well as of the di...
TL;DR: In this article, the authors used N-methyl-2-pyrrolidone (NMP) as the organic component to give six novel complexes, which were crystallographically characterized.
Abstract: Uranyl nitrate was reacted with several polycarboxylic acids under solvo-/hydrothermal conditions using N-methyl-2-pyrrolidone (NMP) as the organic component to give six novel complexes, which were crystallographically characterized. NMP is coordinated to the uranyl ion in all cases but one. The complex with terephthalic acid (H2tph), [UO2(tph)(NMP)] (1), crystallizes as a three-dimensional (3D) framework, an unprecedented feature in uranyl complexes with this ligand. The two complexes obtained with 2,5-thiophenedicarboxylic acid (H2thd), [UO2(thd)(NMP)] (2 and 3), crystallize as 3D frameworks having the same formula and topology but different packings. Two complexes were also obtained with 1,3,5-benzenetriacetic acid (H3bta), [(UO2)3(bta)2(NMP)3]·0.5H2O (4) and [Hbipy][UO2(bta)]·H2O (5). Complex 4, with NMP coordinated, is a 2D assembly, with a sheet thickness of ∼12 A arising from the superposition of three sublayers. Complex 5, obtained in the presence of 2,2′-bipyridine (bipy), is a 1D polymer with a ...
TL;DR: Uranium adsorbed on amidoxime-based polyethylene fiber in simulated seawater can be quantitatively eluted at room temperature using 1 M Na2CO3 containing 0.1 M H2O2 using an extremely stable uranyl-peroxo-carbonato complex in the carbonate solution.
Abstract: Uranium adsorbed on amidoxime-based polyethylene fiber in simulated seawater can be quantitatively eluted at room temperature using 1 M Na2CO3 containing 0.1 M H2O2. This efficient elution process is probably due to the formation of an extremely stable uranyl-peroxo-carbonato complex in the carbonate solution. After washing with water, the sorbent can be reused with minimal loss of uranium loading capacity. Possible existence of this stable uranyl species in ocean water is also discussed.
TL;DR: In this paper, the effect of pH, dissolved inorganic carbon (DIC) concentration, and co-solute composition (e.g., Na+/Ca2+ of the groundwater) on the products and extent of uranium precipitation induced by phosphate addition was studied.
TL;DR: Results implied that the biosorption mechanism of uranium on Bacillus sp.
TL;DR: In this paper, a series of batch reactions were conducted at pH ∼7, [U(VI)] from 1 to 170μm, [Fe(II)] from 0 to 3mM, and [Ca] at 0 or 4mM coupled with spectroscopic examination of reaction products of Fe(II)-induced ferrihydrite transformation.
TL;DR: Analysis of precipitates by U LIII-edge extended X-ray absorption fine structure indicated that "autunite-type" sheets of meta-ankoleite transformed to "phosphuranylite- type" sheets after 30 d of reaction, probably due to Ca substitution in the structure.
Abstract: Uranium speciation and physical–chemical characteristics were studied in solids precipitated from synthetic acidic to circumneutral wastewaters in the presence and absence of dissolved silica and phosphate to examine thermodynamic and kinetic controls on phase formation. Composition of synthetic wastewater was based on disposal sites 216-U-8 and 216-U-12 Cribs at the Hanford site (WA, USA). In the absence of dissolved silica or phosphate, crystalline or amorphous uranyl oxide hydrates, either compreignacite or meta-schoepite, precipitated at pH 5 or 7 after 30 d of reaction, in agreement with thermodynamic calculations. In the presence of 1 mM dissolved silica representative of groundwater concentrations, amorphous phases dominated by compreignacite precipitated rapidly at pH 5 or 7 as a metastable phase and formation of poorly crystalline boltwoodite, the thermodynamically stable uranyl silicate phase, was slow. In the presence of phosphate (3 mM), meta-ankoleite initially precipitated as the primary pha...
TL;DR: The proposed method was successfully utilized in quantifying UO2(2+) in fuel processing wastewaters and showed that a detection limit of 0.2 ppb was achieved with the relative standard deviation (R.S.D.) 1.3% (n=5).
TL;DR: Two trimeric heterodimetallic 3d-5f complexes self-assembled by cation-cation interactions between a uranyl(V) complex and a TPA-capped M(II) complex (M=Mn (1), Cd (2); TPA=tris(2-pyridylmethyl)amine).
Abstract: Mixed-metal uranium compounds are very attractive candidates in the design of single-molecule magnets (SMMs), but only one 3d-5f hetero-polymetallic SMM containing a uranium center is known. Herein, we report two trimeric heterodimetallic 3d-5f complexes self-assembled by cation-cation interactions between a uranyl(V) complex and a TPA-capped M-II complex (M=Mn (1), Cd (2); TPA = tris(2-pyridylmethyl) amine). The metal centers were strategically chosen to promote the formation of discrete molecules rather than extended chains. Compound 1, which contains an almost linear {Mn-O=U=O-Mn} core, exhibits SMM behavior with a relaxation barrier of 81 +/- 0.5 K-the highest reported for a mono-uranium system-arising from intra-molecular Mn-U exchange interactions combined with the high Ising anisotropy of the uranyl(V) moiety. Compound 1 also exhibits an open magnetic hysteresis loop at temperatures less than 3 K, with a significant coercive field of 1.9 T at 1.8 K.
TL;DR: Combining the MD-derived equilibrium adsorption constants for orthoclase with aqueous equilibrium constants for uranyl carbonate species indicates the presence of adsorbed uranium complexes with one or two carbonates under alkaline conditions, in support of current uranium(VI) surface complexation models.
Abstract: Adsorption at mineral surfaces is a critical factor controlling the mobility of uranium(VI) in aqueous environments. Therefore, molecular dynamics (MD) simulations were performed to investigate uranyl(VI) adsorption onto two neutral aluminosilicate surfaces, namely, the orthoclase (001) surface and the octahedral aluminum sheet of the kaolinite (001) surface. Although uranyl preferentially adsorbs as a bidentate inner-sphere complex on both surfaces, the free energy of adsorption on the orthoclase surface (−15 kcal mol–1) is significantly more favorable than that at the kaolinite surface (−3 kcal mol–1), which is attributed to differences in surface functional groups and the ability of the orthoclase surface to release a surface potassium ion upon uranyl adsorption. The structures of the adsorbed complexes compare favorably with X-ray absorption spectroscopy results. Simulations of the adsorption of uranyl complexes with up to three carbonate ligands revealed that uranyl complexes coordinated to up to two...
TL;DR: In this article, three uranyl isophthalates (1,3-bdc) and two uranyl pyromellitates (btec) of coordination-polymer type were hydrothermally synthesized (200 °C for 24 h) in the presence of different amine-based molecules.
Abstract: Three uranyl isophthalates (1,3-bdc) and two uranyl pyromellitates (btec) of coordination-polymer type were hydrothermally synthesized (200 °C for 24 h) in the presence of different amine-based molecules [1,3-diaminopropane (dap) or dimethylamine (dma) originating from the in situ decomposition of N,N-dimethylformamide]. (UO2)2(OH)2(H2O)(1,3-bdc)·H2O (1) is composed of inorganic tetranuclear cores, which are linked to each other through the isophthalato ligand to generate infinite neutral ribbons, which are intercalated by free H2O molecules. The compounds (UO2)1.5(H2O)(1,3-bdc)2·0.5H2dap·1.5H2O (2) and UO2(1,3-bdc)1.5·0.5H2dap·2H2O (3) consist of discrete uranyl-centered hexagonal bipyramids connected to each other by a ditopic linker to form a single-layer network for 2 or a double-layer network for 3. The protonated diamine molecules are located between the uranyl–organic sheets and balance the negative charge of the layered sub-networks. The phase (UO2)2O(btec)·2Hdma·H2O (4) presents a 2D structure built up from tetranuclear units, which consist of two central sevenfold coordinated uranium centers and two peripheral eightfold coordinated uranium centers. The connection of the resulting tetramers through the pyromellitate molecules generates an anionic layerlike structure, in which the protonated dimethylammonium species are inserted. The compound UO2(btec)·2Hdma (5) is also a lamellar coordination polymer, which contains isolated eightfold coordinated uranium cations linked through pyromellitate molecules and intercalated by protonated dimethylammonium species. In both phases 4 and 5, the btec linker has non-bonded carboxyl oxygen atoms, which preferentially interact with the protonated amine molecules through a hydrogen-bond network. The different illustrations show the structural diversity of uranyl–organic coordination polymers with organic amine molecules as countercations.
TL;DR: The molar ellipticity of the uranyl complex at 195 nm is directly correlated to its stability, which demonstrates that the β-sheet structure is optimal for high stability in the peptide series.
Abstract: Peptides are interesting tools to rationalize uranyl–protein interactions, which are relevant to uranium toxicity in vivo Structured cyclic peptide scaffolds were chosen as promising candidates to coordinate uranyl thanks to four amino acid side chains pre-oriented towards the dioxo cation equatorial plane The binding of uranyl by a series of decapeptides has been investigated with complementary analytical and spectroscopic methods to determine the key parameters for the formation of stable uranyl–peptide complexes The molar ellipticity of the uranyl complex at 195 nm is directly correlated to its stability, which demonstrates that the β-sheet structure is optimal for high stability in the peptide series Cyclodecapeptides with four glutamate residues exhibit the highest affinities for uranyl with log KC=80–84 and, therefore, appear as good starting points for the design of high-affinity uranyl-chelating peptides
TL;DR: In this paper, all-cis-1,3,5-Cyclohexanetricarboxylic acid (LH3) was reacted with uranyl nitrate under solvo-hydrothermal conditions, either alone or in the presence of additional metal cations (Na+, K+, Ni2+, Cu2+, or Tb3+), resulting in the crystallization of a series of eight complexes which were characterized by their crystal structures and luminescence properties.
Abstract: all-cis-1,3,5-Cyclohexanetricarboxylic acid (LH3) was reacted with uranyl nitrate under solvo-hydrothermal conditions, either alone or in the presence of additional metal cations (Na+, K+, Ni2+, Cu2+, or Tb3+), resulting in the crystallization of a series of eight complexes which were characterized by their crystal structures and luminescence properties. The six complexes [UO2(H2O)5][UO2(L)]2·2H2O·3THF (1), [Ni(bipy)2(H2O)2][UO2(L)]2·4H2O (2), [Ni(bipy)3][Ni(bipy)2(H2O)2][UO2(L)]4·5H2O (3), [Ni(H2O)6][UO2(L)]2·2H2O (4), [Cu(H2O)6][UO2(L)]2·2H2O (5), and [Tb(H2O)8][UO2(L)]3·8H2O (6) all contain the same {UO2(L)−}∞ anionic motif, in which the uranyl ion is tris-chelated by three L3– anions to give a two-dimensional assembly with hexagonal {63} topology. The reaction of uranyl nitrate alone with LH3 in water/N-methyl-2-pyrrolidone (NMP) yields the complex [(UO2)3(L)2(NMP)2] (7), which crystallizes as a three-dimensional framework. Finally, in the presence of Na+, K+, or even Kemp’s triacid (cis,cis-1,3,5-tri...
TL;DR: In this article, a comprehensive review of the crystal structures resulting from the different types of complexation of uranium with carboxylic acid molecules (excepting oxalate ligand) and their classification as a function of the nuclearity of identified building units is presented.
Abstract: The field of uranium carboxylates has been studied for several decades and an important library of coordination complexes and network solids is now well defined. It mainly concerns the reactivity of hexavalent uranium (uranyl) with the different types of carboxylic acids containing monodentate or polydentate functions, aliphatic or aromatic carbon backbone, or hetero-systems offering other functionalities (N-donor, S-donor, phosphonates, …). A rich variety of molecular complexes or extended multi-dimensional networks (1D, 2D, 3D) has been identified and depends mainly on the equatorial connectivity of the uranyl cation (UO22+) in different coordination numbers (tetragonal, pentagonal or hexagonal bipyramid). The yl oxo groups remain relatively inert to condensation process (except rare case of cation–cation interaction). For lower oxidation state of uranium (+3, +4, +5), the knowledge is at the infancy stage since very few contributions are available in literature. Nevertheless, recent contributions have shown the possibilities of the reactivity of tetravalent uranium in relatively stable architectures, either at the molecular level, with high nuclearities (up to U38), or engaged in three-dimensional frameworks. The scope of this review is a comprehensive presentation of the crystal structures resulting from the different types of complexation of uranium with carboxylic acid molecules (excepting oxalate ligand) and their classification as a function of the nuclearity of identified building units.
TL;DR: The uranyl complex of [1 - 4H](2-) displays solid-state structural and solution-phase spectroscopic features consistent with contributions to the overall electronic structure that involve a conjugated, (4n + 2) π-electron aromatic periphery.
Abstract: Reported here is a new hybrid macrocycle, cyclo[1]furan[1]pyridine[4]pyrrole (1), that bears analogy to the previously reported mixed heterocycle system cyclo[2]pyridine[4]pyrrole (2) and cyclo[6]pyrrole 3, an all-pyrrole 22 π-electron aromatic expanded porphyrin. The oxidized, dianionic form of 1, [1 - 4H](2-), has been characterized as its uranyl complex. In contrast to 2 and 3 and in spite of the presence of a 2,6-disubstituted pyridine subunit, the uranyl complex of [1 - 4H](2-) displays solid-state structural and solution-phase spectroscopic features consistent with contributions to the overall electronic structure that involve a conjugated, (4n + 2) π-electron aromatic periphery.
TL;DR: In this paper, the results of the extraction of uranyl ion from nitric acid feed solutions using solutions of tri-n-octyl phosphine oxide (TOPO) in several room temperature ionic liquids (RTIL), viz. [C4mim][PF6], [C6mim+ as the cationic part showed significantly higher extraction efficiency.
TL;DR: In this paper, poly(acrylic acid)- block -polystyrene (PAA- b -PSt) block copolymers were synthesized as macromolecular surfactant for the emulsion polymerization of styrene.
TL;DR: In this article, a super tetrahedral cluster containing 124 uranyl hexagonal bipyramids and 32 phosphate tetrahedra was constructed, and four symmetrically identical cage clusters, each built from 23 uranyl Hexagonal bipyreramids and eight phosphate tetrashedra, as well as a central cage defined by 52 uranylhexagonal biperamids.
Abstract: Combination of uranyl, peroxide, phosphate, and counter ions under ambient conditions in aqueous solution over the pH range 5.5–6.5 results in the self-assembly of a large super tetrahedral cluster containing 124 uranyl hexagonal bipyramids and 32 phosphate tetrahedra designated U124P32. With a diameter of 4 nm, U124P32 consists of four symmetrically identical cage clusters, each built from 23 uranyl hexagonal bipyramids and eight phosphate tetrahedra, as well as a central cage defined by 52 uranyl hexagonal bipyramids and 32 phosphate tetrahedra. It is the first uranyl-based cluster that contains multiple cages and it also has the highest number of uranyl ions. U124P32 contains 152 peroxide groups that are bidentate bridges between uranyl ions. Crystals of U124P32 provided structural details, and were dissolved for subsequent small-angle X-ray scattering and electrospray ionization mass spectrometry characterization that indicated U124P32 remains intact upon dissolution in water. Whereas uranyl phosphates are generally insoluble in water, prompting interest in their applications in remediating contaminated water, U124P32 is highly soluble, reflecting the impact of the nanoscale structure on solubility.
TL;DR: In this article, a unique example of topology tailoring in a uranyl-organic system is provided by the three-pronged Kemp's tricarboxylate ligand.
Abstract: A unique example of topology tailoring in a uranyl–organic system is provided by the three-pronged Kemp’s tricarboxylate ligand. While unexceptional one-dimensional polymers are formed with uranyl alone under solvo-hydrothermal conditions, addition of Ni2+ ions yields the nanotubular species [(UO2)2Ni(L)2(H2O)4]∞, with a hydrophilic inner cavity lined by hydrated Ni2+ ions, and a hydrophobic outer surface. The further presence of 2,2′-bipyridine brings about the trapping of Ni2+ ions into counterions and formation of the octanuclear pseudocubic cage [(UO2)8(L)6(H2O)6]2–.
TL;DR: In this article, four complexes were obtained from reaction of uranyl nitrate with (1R,3S)-(+)-camphoric acid under solvo-/hydrothermal conditions with either acetonitrile or N-methyl-2-pyrrolidone (NMP) as the organic component.
Abstract: Four complexes were obtained from reaction of uranyl nitrate with (1R,3S)-(+)-camphoric acid under solvo-/hydrothermal conditions with either acetonitrile or N-methyl-2-pyrrolidone (NMP) as the organic component. All complexes crystallize in chiral space groups and are enantiopure species. Complexes [(UO2)4(L)3(OH)2(H2O)4]·3H2O (1) and [(UO2)8K8(L)12(H2O)12]·H2O (2) were obtained in water–acetonitrile in the presence of LiOH or KOH in excess beyond or equal to that simply required to neutralize the acid, respectively. Whereas 1 is a 1D coordination polymer including hydroxide ions resulting from hydrolysis of the uranyl aqua-ion, 2 contains octanuclear uranyl camphorate cages analogous, but for their crystallographic symmetry, to those previously published; these cages are assembled into a 3D framework by bridging potassium ions. The two complexes obtained in water–NMP, [UO2(L)(NMP)] (3) and [(UO2)2Cu(L)3(NMP)2] (4), are devoid both of water molecules and any solvent-derived anions, and they crystallize as 2D assemblies. The sheets in 4, with a thickness of ~14 A, display a central layer of copper(II) ions surrounded by two layers of uranyl ions. These and previous results suggest that solvo-/hydrothermal conditions using NMP provide a new means of avoiding the formation of uranyl-containing oligomeric or 1D polymeric hydrolysis products which are frequent and often unpredictable outcomes in the synthesis of uranyl–organic assemblies under aqueous conditions, especially in the presence of cosolvents which in themselves are susceptible to hydrolysis. The emission spectrum of compound 3 under excitation at 350 nm displays the usual vibronic fine structure in the ~460–600 nm range, while uranyl luminescence is quenched by Cu(II) cations in complex 4.