View article
Identification of the Formal +2 Oxidation State of Neptunium: Synthesis and Structural Characterization of {Np<sup>II</sup>[C<sub>5</sub>H<sub>3</sub>(SiMe<sub>3</sub>)<sub>2</sub>]<sub>3</sub>}<sup>1–</sup> Open
We report a new formal oxidation state for neptunium in a crystallographically characterizable molecular complex, namely Np2+ in [K(crypt)][NpIICp″3] [crypt = 2.2.2-cryptand, Cp″ = C5H3(SiMe3)2]. Density functional theory calculations indi…
View article
Organometallic Neptunium Chemistry Open
Fifty years have passed since the foundation of organometallic neptunium chemistry, and yet only a handful of complexes have been reported, and even fewer have been fully characterized. Yet, increasingly, combined synthetic/spectroscopic/c…
View article
Reduction chemistry of neptunium cyclopentadienide complexes: from structure to understanding Open
Structural investigation on neptunium cyclopentadienyl organometallic complexes in the formal oxidation states II, III, and IV: similarities and differences between Np and U.
View article
Facile and Efficient Decontamination of Thorium from Rare Earths Based on Selective Selenite Crystallization Open
The coexistence of radioactive contaminants (e.g., thorium, uranium, and their daughters) in rare earth minerals introduces significant environmental, economic, and technological hurdles in modern rare earth production. Efficient, low cost…
View article
In Situ Formation of Unprecedented Neptunium-Oxide Wheel Clusters Stabilized in a Metal–Organic Framework Open
An isostructural series of Np(V) MOFs with shp-topology were synthesized and characterized. X-ray diffraction data revealed an unusual wheel-shaped node of 18 neptunyl polyhedra stabilized in the framework. Strong distortion in local coord…
View article
Dynamics of the peptidoglycan biosynthetic machinery in the stalked budding bacterium <i>Hyphomonas neptunium</i> Open
Summary Most commonly studied bacteria grow symmetrically and divide by binary fission, generating two siblings of equal morphology. An exception to this rule are budding bacteria, in which new offspring emerges de novo from a morphologica…
View article
In-Plane Thorium(IV), Uranium(IV), and Neptunium(IV) Expanded Porphyrin Complexes Open
Here we report the first series of in-plane thorium(IV), uranium(IV), and neptunium(IV) expanded porphyrin complexes. These actinide (An) complexes were synthesized using a hexa-aza porphyrin analogue, termed dipyriamethyrin, and the nonaq…
View article
A Linear <i>trans</i>-Bis(imido) Neptunium(V) Actinyl Analog: Np<sup>V</sup>(NDipp)<sub>2</sub>(<i><sup><i>t</i></sup></i>Bu<sub>2</sub>bipy)<sub>2</sub>Cl (Dipp = 2,6-<sup><i>i</i></sup>Pr<sub>2</sub>C<sub>6</sub>H<sub>3</sub>) Open
The discovery that imido analogs of actinyl dioxo cations can be extended beyond uranium into the transuranic elements is presented. Synthesis of the Np(V) complex, Np(NDipp)2((t)Bu2bipy)2Cl (1), is achieved through treatment of a Np(IV) p…
View article
Characterization of Americium and Curium Complexes with the Protein Lanmodulin: A Potential Macromolecular Mechanism for Actinide Mobility in the Environment Open
Anthropogenic radionuclides, including long-lived heavy actinides such as americium and curium, represent the primary long-term challenge for management of nuclear waste. The potential release of these wastes into the environment necessita…
View article
{Np<sub>38</sub>} clusters: the missing link in the largest poly-oxo cluster series of tetravalent actinides Open
The poly-oxo clusters of neptunium, {Np38}, fill the gap in the largest poly-oxo cluster series of tetravalent actinides.
View article
A density functional theory study of uranium-doped thoria and uranium adatoms on the major surfaces of thorium dioxide Open
Thorium dioxide is of significant research interest for its use as a nuclear fuel, particularly as part of mixed oxide fuels. We present the results of a DFT study of uranium-substituted thorium dioxide, where we found that increasing leve…
View article
Simulation of Neptunium Extraction in an Advanced PUREX Process—Model Improvement Open
Routing neptunium to a single product in spent nuclear fuel reprocessing is a significant challenge. In this work, we have further improved the simulation of neptunium extraction in an advanced PUREX flowsheet by applying a revised model o…
View article
Influence of riboflavin on the reduction of radionuclides by Shewanella oneidenis MR-1 Open
Uranium (as UO22+), technetium (as TcO4−) and neptunium (as NpO2+) are highly mobile radionuclides that can be reduced enzymatically by a range of anaerobic and facultatively anaerobic microorganisms, includingShewanella oneidensisMR-1, to…
View article
Two-step chromosome segregation in the stalked budding bacterium Hyphomonas neptunium Open
Chromosome segregation typically occurs after replication has finished in eukaryotes but during replication in bacteria. Here, we show that the alphaproteobacterium Hyphomonas neptunium , which proliferates by bud formation at the tip of a…
View article
Sensitive Redox Speciation of Iron, Neptunium, and Plutonium by Capillary Electrophoresis Hyphenated to Inductively Coupled Plasma Sector Field Mass Spectrometry Open
The long-term safety assessment for nuclear waste repositories requires a detailed understanding of actinide (geo)chemistry. Advanced analytical tools are required to gain insight into actinide speciation in a given system. The geochemical…
View article
Complexation and redox chemistry of neptunium, plutonium and americium with a hydroxylaminato ligand Open
The coordination modes and electronic properties of a strongly coordinating hydroxylaminato ligand with Np, Pu and Am were investigated.Complexes were characterized by a range of experimental and computational techniques.
View article
Observation of a promethium complex in solution Open
Lanthanide rare-earth metals are ubiquitous in modern technologies 1–5 , but we know little about chemistry of the 61st element, promethium (Pm) 6 , a lanthanide that is highly radioactive and inaccessible. Despite its importance 7,8 , Pm …
View article
Neptunium and plutonium complexes with a sterically encumbered triamidoamine (TREN) scaffold Open
The syntheses and characterisation of isostructural neptunium(iv) and plutonium(iv) complexes [AnIV(TRENTIPS)(Cl)] [An = Np, Pu; TRENTIPS = {N(CH2CH2NSiPri3)3}3−] are reported.
View article
Competitive Reaction of Neptunium(V) and Uranium(VI) in Potassium–Sodium Carbonate-Rich Aqueous Media: Speciation Study with a Focus on High-Resolution X-ray Spectroscopy Open
Neptunium(V) and uranium(VI) are precipitated from an aqueous potassium-sodium-containing carbonate-rich solution, and the solid phases are investigated. U/Np M4,5-edge high-energy resolution X-ray absorption near edge structure (HR-XANES)…
View article
Redox behavior and solubility of plutonium under alkaline, reducing conditions Open
The solubility and redox behavior of hydrous Pu(IV) oxide was comprehensively investigated by an experimental multi-method approach as a function of different redox conditions in 0.1 M NaCl solutions, allowing a detailed characterization o…
View article
Non-aqueous neptunium and plutonium redox behaviour in THF – access to a rare Np(<span>iii</span>) synthetic precursor Open
Redox stability of tetravalent Np and Pu in THF is explored, leading to facile access routes into anhydrous Np(iii) chemistry.
View article
A Computational Assessment of Actinide Dioxide Cations AnO<sub>2</sub><sup>2+</sup>for An = U to Lr: The Limited Stability Range of the Hexavalent Actinyl Moiety, [O═An═O]<sup>2+</sup> Open
In this work, the isolated gas-phase actinide dioxide dications, AnO22+, were evaluated by DFT and coupled cluster CCSD(T) calculations for 12 actinides, An = U–Lr. CASSCF calculations were used to define the orbitals for the CCSD(T) calcu…
View article
Controls on the Fate and Speciation of Np(V) During Iron (Oxyhydr)oxide Crystallization Open
The speciation and fate of neptunium as Np(V)O2(+) during the crystallization of ferrihydrite to hematite and goethite was explored in a range of systems. Adsorption of NpO2(+) to iron(III) (oxyhydr)oxide phases was reversible and, for fer…
View article
Coordination Chemistry of Homoleptic Actinide(IV)–Thiocyanate Complexes Open
The synthesis, X‐ray crystal structure, vibrational and optical spectroscopy for the eight‐coordinate thiocyanate compounds, [Et 4 N] 4 [Pu IV (NCS) 8 ], [Et 4 N] 4 [Th IV (NCS) 8 ], and [Et 4 N] 4 [Ce III (NCS) 7 (H 2 O)] are reported. Th…
View article
Divergent Stabilities of Tetravalent Cerium, Uranium, and Neptunium Imidophosphorane Complexes** Open
The study of the redox chemistry of mid‐actinides (U−Pu) has historically relied on cerium as a model, due to the accessibility of trivalent and tetravalent oxidation states for these ions. Recently, dramatic shifts of lanthanide 4+/3+ non…
View article
Development and Validation of a Flowsheet Simulation Model for Neptunium Extraction in an Advanced PUREX Process Open
An Advanced PUREX process has been developed for separation and recycling of neptunium from spent nuclear fuel. This work presents a new flowsheet simulation model for the extraction of neptunium using centrifugal contactors, where mass tr…
View article
Hidden order and multipolar exchange striction in a correlated <i>f</i> -electron system Open
Significance Second-order phase transitions in solids occur due to spontaneous symmetry breaking with an order parameter continuously emerging from the disordered high-temperature phase. In some materials, the phase transitions are clearly…
View article
Synthesis and investigation of neptunium zirconium phosphate, a member of the NZP family: crystal structure, thermal behaviour and Mössbauer spectroscopy studies Open
We synthesized a new NZP-type neptunium zirconium phosphate Np0.29Zr2(PO4)3 and investigated it by Rietveld analysis, infrared spectroscopy and Mössbauer spectroscopy.
View article
Carbene Complexes of Neptunium Open
Since the advent of organotransuranium chemistry six decades ago, structurally verified complexes remain restricted to π-bonded carbocycle and σ-bonded hydrocarbyl derivatives. Thus, transuranium-carbon multiple or dative bonds are yet to …
View article
Tris‐{hydridotris(1‐pyrazolyl)borato}actinide Complexes: Synthesis, Spectroscopy, Crystal Structure, Bonding Properties and Magnetic Behaviour Open
The isostructural compounds of the trivalent actinides uranium, neptunium, plutonium, americium, and curium with the hydridotris(1‐pyrazolyl)borato (Tp) ligand An[η 3 ‐HB(N 2 C 3 H 3 ) 3 ] 3 (AnTp 3 ) have been obtained through several syn…