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1.
Subtle Interactions and Electron Transfer between UIII,NpIII, or PuIII and Uranyl Mediated by the Oxo Group 下载免费PDF全文
Prof. Polly L. Arnold Michał S. Dutkiewicz Dr. Markus Zegke Dr. Olaf Walter Dr. Christos Apostolidis Dr. Emmalina Hollis Dr. Anne‐Fréderique Pécharman Dr. Nicola Magnani Dr. Jean‐Christophe Griveau Dr. Eric Colineau Prof. Roberto Caciuffo Xiaobin Zhang Prof. Georg Schreckenbach Prof. Jason B. Love 《Angewandte Chemie (International ed. in English)》2016,55(41):12797-12801
A dramatic difference in the ability of the reducing AnIII center in AnCp3 (An=U, Np, Pu; Cp=C5H5) to oxo‐bind and reduce the uranyl(VI) dication in the complex [(UO2)(THF)(H2L)] (L=“Pacman” Schiff‐base polypyrrolic macrocycle), is found and explained. These are the first selective functionalizations of the uranyl oxo by another actinide cation. At‐first contradictory electronic structural data are explained by combining theory and experiment. Complete one‐electron transfer from Cp3U forms the UIV‐uranyl(V) compound that behaves as a UV‐localized single molecule magnet below 4 K. The extent of reduction by the Cp3Np group upon oxo‐coordination is much less, with a NpIII‐uranyl(VI) dative bond assigned. Solution NMR and NIR spectroscopy suggest NpIVUV but single‐crystal X‐ray diffraction and SQUID magnetometry suggest a NpIII‐UVI assignment. DFT‐calculated Hirshfeld charge and spin density analyses suggest half an electron has transferred, and these explain the strongly shifted NMR spectra by spin density contributions at the hydrogen nuclei. The PuIII–UVI interaction is too weak to be observed in THF solvent, in agreement with calculated predictions. 相似文献
2.
Radmila Faizova Farzaneh Fadaei‐Tirani Rizlan Bernier‐Latmani Marinella Mazzanti 《Angewandte Chemie (International ed. in English)》2020,59(17):6756-6759
Reduction of uranyl(VI) to UV and to UIV is important in uranium environmental migration and remediation processes. The anaerobic reduction of a uranyl UVI complex supported by a picolinate ligand in both organic and aqueous media is presented. The [UVIO2(dpaea)] complex is readily converted into the cis‐boroxide UIV species via diborane‐mediated reductive functionalization in organic media. Remarkably, in aqueous media the uranyl(VI) complex is rapidly converted, by Na2S2O4, a reductant relevant for chemical remediation processes, into the stable uranyl(V) analogue, which is then slowly reduced to yield a water‐insoluble trinuclear UIV oxo‐hydroxo cluster. This report provides the first example of direct conversion of a uranyl(VI) compound into a well‐defined molecular UIV species in aqueous conditions. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(36):10915-10919
The reduction of UVI uranyl halides or amides with simple LnII or UIII salts forms highly symmetric, linear, oxo‐bridged trinuclear UV/LnIII/UV, LnIII/UIV/LnIII, and UIV/UIV/UIV complexes or linear LnIII/UV polymers depending on the stoichiometry and solvent. The reactions can be tuned to give the products of one‐ or two‐electron uranyl reduction. The reactivity and magnetism of these compounds are discussed in the context of using a series of strongly oxo‐coupled homo‐ and heterometallic poly(f‐block) chains to better understand fundamental electronic structure in the f‐block. 相似文献
4.
Isolation of a Star‐Shaped Uranium(V/VI) Cluster from the Anaerobic Photochemical Reduction of Uranyl(VI) 下载免费PDF全文
Lucile Chatelain Sarah White Dr. Rosario Scopelliti Prof. Marinella Mazzanti 《Angewandte Chemie (International ed. in English)》2016,55(46):14325-14329
Actinide oxo clusters are an important class of compounds due to their impact on actinide migration in the environment. The photolytic reduction of uranyl(VI) has potential application in catalysis and spent nuclear fuel reprocessing, but the intermediate species involved in this reduction have not yet been elucidated. Here we show that the photolysis of partially hydrated uranyl(VI) in anaerobic conditions leads to the reduction of uranyl(VI), and to the incorporation of the resulting UV species into the stable mixed‐valent star‐shaped UVI/UV oxo cluster [U(UO2)5(μ3‐O)5(PhCOO)5(Py)7] ( 1 ). This cluster is only the second example of a UVI/UV cluster and the first one associating uranyl groups to a non‐uranyl(V) center. The UV center in 1 is stable, while the reaction of uranyl(V) iodide with potassium benzoate leads to immediate disproportionation and formation of the U12IVU4VO24 cluster {[K(Py)2]2[K(Py)]2[U16O24(PhCOO)24(Py)2]} ( 5 ). 相似文献
5.
Radmila Faizova Dr. Farzaneh Fadaei-Tirani Prof. Dr. Rizlan Bernier-Latmani Prof. Dr. Marinella Mazzanti 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(17):6822-6825
Reduction of uranyl(VI) to UV and to UIV is important in uranium environmental migration and remediation processes. The anaerobic reduction of a uranyl UVI complex supported by a picolinate ligand in both organic and aqueous media is presented. The [UVIO2(dpaea)] complex is readily converted into the cis-boroxide UIV species via diborane-mediated reductive functionalization in organic media. Remarkably, in aqueous media the uranyl(VI) complex is rapidly converted, by Na2S2O4, a reductant relevant for chemical remediation processes, into the stable uranyl(V) analogue, which is then slowly reduced to yield a water-insoluble trinuclear UIV oxo-hydroxo cluster. This report provides the first example of direct conversion of a uranyl(VI) compound into a well-defined molecular UIV species in aqueous conditions. 相似文献
6.
Dr. Sumit Kumar Assist. Prof. Gaëlle Creff Dr. Christoph Hennig Dr. André Rossberg Dr. Robin Steudtner Dr. Johannes Raff Dr. Claude Vidaud Dr. François R. Oberhaensli Dr. Marie-Yasmine Dechraoui Bottein Prof. Christophe Den Auwer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(53):12332-12341
7.
Mechanistic Features of the TiO2 Heterogeneous Photocatalysis of Arsenic and Uranyl Nitrate in Aqueous Suspensions Studied by the Stopped‐Flow Technique 下载免费PDF全文
Dr. Jorge M. Meichtry Dr. Ivana K. Levy Dr. Hanan H. Mohamed Dr. Ralf Dillert Prof. Detlef W. Bahnemann Prof. Marta I. Litter 《Chemphyschem》2016,17(6):885-892
The dynamics of the transfer of electrons stored in TiO2 nanoparticles to AsIII, AsV, and uranyl nitrate in water was investigated by using the stopped‐flow technique. Suspensions of TiO2 nanoparticles with stored trapped electrons (etrap?) were mixed with solutions of acceptor species to evaluate the reactivity by following the temporal evolution of etrap? by the decrease in the absorbance at λ=600 nm. The results indicate that AsV and AsIII cannot be reduced by etrap? under the reaction conditions. In addition, it was observed that the presence of AsV and AsIII strongly modified the reaction rate between O2 and etrap?: an increase in the rate was observed if AsV was present and a decrease in the rate was observed in the presence of AsIII. In contrast with the As system, UVI was observed to react easily with etrap? and UIV formation was observed spectroscopically at λ=650 nm. The possible competence of UVI and NO3? for their reduction by etrap? was analyzed. The inhibition of the UVI photocatalytic reduction by O2 could be attributed to the fast oxidation of UV and/or UIV. 相似文献
8.
Grigor'ev M. S. Fedoseev A. M. Budantseva N. A. 《Russian Journal of Coordination Chemistry》2003,29(12):877-879
The crystal structure of the mixed-valence Np(V) and Np(VI) compound Na6[(NpVO2)2(NpVIO2)(MoO4)5] · 13H2O was determined. The structure is built of the anionic layers [(NpVO2)2(NpVIO2)(MoO4)5]
6n-
n with the Na+ cations and crystal water molecules between them. The Np(V) and Np(VI) atoms in the anionic layers are ordered. The motif of the anionic layer is close to that found in Mg2[(UO2)3(SeO4)5] · 16H2O. The isostructural mixed-valence Np(V) and U(VI) compound was also synthesized. 相似文献
9.
Jun-Bo Lu Xue-Lian Jiang Jia-Qi Wang Han-Shi Hu W. H. Eugen Schwarz Jun Li 《Journal of computational chemistry》2023,44(3):190-198
Actinoid tetroxide molecules AnO4 (An = Ac – Cm) are investigated with the ab initio density matrix renormalization group (DMRG) approach. Natural orbital shapes are used to read out the oxidation state (OS) of the f-elements, and the atomic orbital energies and radii are used to explain the trends. The highest OSs reveal a “volcano”-type variation: For An = Ac – Np, the OSs are equal to the number of available valence electrons, that is, AcIII, ThIV, PaV, UVI, and NpVII. Starting with plutonium as the turning point, the highest OSs in the most stable AnO4 isomers then decrease as PuV, AmV, and CmIII, indicating that the 5f-electrons are hard to be fully oxidized off from Pu onward. The variations are related to the actinoid contraction and to the 5f-covalency characteristics. Combined with previous work on OSs, we review their general trends throughout the periodic table, providing fundamental understanding of OS-relevant phenomena. 相似文献
10.
Aleksander Fedoseev Iraida Charushnikova Nina Budantseva Grigory Andreev 《无机化学与普通化学杂志》2019,645(22):1296-1302
Behavior of UVI, NpVI and PuVI in water‐acetonitrile solutions was studied spectrophotometrically with the successive addition of the polar organic ligands (dimethyl sulfoxide or hexamethylphosphoric triamide) and the NCS– ion. The detected spectral effects – changes in the absorption intensity, bathochromic shifts in the absorption bands, the absence of isosbestic points, a change in the color of the solution – indicate complex competitive processes occurring in the studied solutions. In the case of NpVI, its partial reduction to NpIV by NCS– ion is observed. Solid UVI complex, [UO2(HMPA)2(NCS)2], was isolated, its crystal structure was determined using X‐ray diffraction. In contrast to known AnO22+ compounds with the NCS– ion, this complex exhibits tetragonal bipyramidal environment of the U atom. [UO2(HMPA)2(NCS)2] is also characterized by UV/Vis, IR and luminescence spectroscopy. 相似文献
11.
Lanhua Chen Dr. Tao Zheng Dr. Songsong Bao Dr. Linjuan Zhang Hsin‐Kuan Liu Prof. Limin Zheng Prof. Jianqiang Wang Yaxing Wang Prof. Juan Diwu Prof. Zhifang Chai Prof. Thomas E. Albrecht‐Schmitt Prof. Shuao Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(34):11954-11957
It is shown that UVO2+ ions can reside at UVIO22+ lattice sites during mild reduction and crystallization process under solvothermal conditions, yielding a complicated and rare mixed‐valent uranium phosphonate compound that simultaneously contains UIV, UV, and UVI. The presence of uranium with three oxidation states was confirmed by various characterization techniques, including X‐ray crystallography, X‐ray photoelectron, electron paramagnetic resonance, FTIR, UV/Vis‐NIR absorption, and synchrotron radiation X‐ray absorption spectroscopy, and magnetism measurements. 相似文献
12.
1,10‐Phenanthroline and Non‐Symmetrical 1,3,5‐Triazine Dipicolinamide‐Based Ligands For Group Actinide Extraction 下载免费PDF全文
Dr. Julia Bisson Dr. Jérémy Dehaudt Dr. Marie‐Christine Charbonnel Dr. Denis Guillaneux Dr. Manuel Miguirditchian Dr. Cécile Marie Nathalie Boubals Guy Dutech Dr. Muriel Pipelier Dr. Virginie Blot Prof. Didier Dubreuil 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(25):7819-7829
The synthesis and evaluation of new extractants for spent nuclear fuel reprocessing are described. New bitopic ligands constituted of phenanthroline and 1,3,5‐triazine cores functionalized by picolinamide groups were designed. Synthetic routes were investigated and optimized to obtain twelve new polyaza‐heterocyclic ligands. In particular, an efficient and versatile methodology was developed to access non‐symmetric 2‐substituted‐4,6‐di(6‐picolin‐2‐yl)‐1,3,5‐triazines from the 1,3,5‐triazapentadiene precursor in the presence of anhydride reagents. Extraction studies showed the ability of both ligand series to extract and separate actinides selectively at different oxidation states (UVI, NpV,VI, AmIII, CmIII, and PuIV) from an acidic solution (3 M HNO3). Phenanthroline‐based ligands show the most promising efficiency for use in the group actinide extraction (GANEX) process due to a higher number of donor nitrogen atoms and a suitable pre‐organization of the dipicolinamide‐1,10‐phenanthroline architecture. 相似文献
13.
Alexander J. Myers Michael L. Tarlton Steven P. Kelley Wayne W. Lukens Justin R. Walensky 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(42):15033-15037
To extend organoactinide chemistry beyond uranium, reported here is the first structurally characterized transuranic hydrocarbyl complex, Np[η4‐Me2NC(H)C6H5]3 ( 1 ), from reaction of NpCl4(DME)2 with four equivalents of K[Me2NC(H)C6H5]. Unlike the UIII species, the neptunium analogue can be used to access other NpIII complexes. The reaction of 1 with three equivalents of HE2C(2,6‐Mes2‐C6H3) (E=O, S) yields [(2,6‐Mes2‐C6H3)CE2]3Np(THF)2, maintaining the trivalent oxidation state. 相似文献
14.
The determination of the two species of uranium(VI and IV) present in 6 uranium ores was studied in relation to the chemical and mineralogical composition, humidity, and pH of the samples taken over from the mine. X‐ray diffraction studies, performed on the uranium ores in powder form allowed to establish their mineralogical composition. Thechemical analysis pointed out the presence, besides the two uranium species, of some microelements able to influence the UVI/UIV ratio in minerals and to leach out UVI as uranyl ions from the corresponding minerals. 相似文献
15.
Summary The polarography of hexavalent uranium in sulphuric acid solutions of different concentrations and solutions containing sodium sulphate is studied. In 0.01 M H2SO4 three waves are obtained corresponding to the successive reduction of UVI to UV, UV to UIV and UIV to UIII. The second and third waves intermingle by increasing the H2SO4 concentration up to 0.055 M or by adding Na2SO4 or sulphosalicylic acid. In 0.25 M H2SO4 or in the presence of EDTA the second wave shifts to less negative potentials and intermingles with the first wave, forming a single wave along which reduction of UVI gives a mixture of UV and UIV. The diffusion current of this wave increases up to 1 M H2SO4 and then decreases above this acidity. The diffusion current measured at –0.6 V is proportional to the UVI concentration in the presence of 0.25–0.6 M H2SO4. This is not the case in the presence of EDTA. The proportionality is better at lower than at higher acidity.Part I: See Z. analyt. Chem.174, 4 (1960). 相似文献
16.
Dr. Clément Falaise Dr. Christophe Volkringer Dr. Christoph Hennig Dr. Thierry Loiseau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16654-16664
The ex‐situ qualitative study of the kinetic formation of the poly‐oxo cluster U38, has been investigated after the solvothermal reaction. The resulting products have been characterized by means of powder XRD and scanning electron microscopy (SEM) for the solid phase and UV/Vis, X‐ray absorption near edge structure (XANES), extended X‐ray absorption fine structure (EXAFS), and NMR spectroscopies for the supernatant liquid phase. The analysis of the different synthesis batches, stopped at different reaction times, revealed the formation of spherical crystallites of UO2 from t=3 h, after the formation of unknown solid phases at an early stage. The crystallization of U38 occurred from t=4 h at the expense of UO2, and is completed after t=8 h. Starting from pure uranium(IV) species in solution (t=0–1 h), oxidation reactions are observed with a UIV/UVI ratio of 70:30 for t=1–3 h. Then, the ratio is inversed with a UIV/UVI ratio of 25/75, when the precipitation of UO2 occurs. Thorough SEM observations of the U38 crystallites showed that the UO2 aggregates are embedded within. This may indicate that UO2 acts as reservoir of uranium(IV), for the formation of U38, stabilized by benzoate and THF ligands. During the early stages of the U38 crystallization, a transient crystallized phase appeared at t=4 h. Its crystal structure revealed a new dodecanuclear moiety (U12), based on the inner hexanuclear core of {U6O8} type, decorated by three additional pairs of dinuclear U2 units. The U12 motif is stabilized by benzoate, oxalates, and glycolate ligands. 相似文献
17.
Guy M. Jones Prof. Polly L. Arnold Dr. Jason B. Love 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(31):10287-10294
Simple and versatile routes to the functionalization of uranyl‐derived UV–oxo groups are presented. The oxo‐lithiated, binuclear uranium(V)–oxo complexes [{(py)3LiOUO}2(L)] and [{(py)3LiOUO}(OUOSiMe3)(L)] were prepared by the direct combination of the uranyl(VI) silylamide “ate” complex [Li(py)2][(OUO)(N”)3] (N”=N(SiMe3)2) with the polypyrrolic macrocycle H4L or the mononuclear uranyl (VI) Pacman complex [UO2(py)(H2L)], respectively. These oxo‐metalated complexes display distinct U? O single and multiple bonding patterns and an axial/equatorial arrangement of oxo ligands. Their ready availability allows the direct functionalization of the uranyl oxo group leading to the binuclear uranium(V) oxo–stannylated complexes [{(R3Sn)OUO}2(L)] (R=nBu, Ph), which represent rare examples of mixed uranium/tin complexes. Also, uranium–oxo‐group exchange occurred in reactions with [TiCl(OiPr)3] to form U‐O? C bonds [{(py)3LiOUO}(OUOiPr)(L)] and [(iPrOUO)2(L)]. Overall, these represent the first family of uranium(V) complexes that are oxo‐functionalised by Group 14 elements. 相似文献
18.
Christopher J. Hoerger Frank W. Heinemann Elisa Louyriac Massimo Rigo Laurent Maron Hansjrg Grützmacher Matthias Driess Karsten Meyer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(6):1693-1697
Reaction of the trivalent uranium complex [((Ad,MeArO)3N)U(DME)] with one molar equiv [Na(OCAs)(dioxane)3], in the presence of 2.2.2‐crypt, yields [Na(2.2.2‐crypt)][{((Ad,MeArO)3N)UIV(THF)}(μ‐O){((Ad,MeArO)3N)UIV(CAs)}] ( 1 ), the first example of a coordinated η1‐cyaarside ligand (CAs?). Formation of the terminal CAs? is promoted by the highly reducing, oxophilic UIII precursor [((Ad,MeArO)3N)U(DME)] and proceeds through reductive C?O bond cleavage of the bound arsaethynolate anion, OCAs?. If two equiv of OCAs? react with the UIII precursor, the binuclear, μ‐oxo‐bridged U2IV/IV complex [Na(2.2.2‐crypt)]2[{((Ad,MeArO)3N)UIV}2(μ‐O)(μ‐AsCAs)] ( 2 ), comprising the hitherto unknown μ:η1,η1‐coordinated (AsCAs)2? ligand, is isolated. The mechanistic pathway to 2 involves the decarbonylation of a dimeric intermediate formed in the reaction of 1 with OCAs?. An alternative pathway to complex 2 is by conversion of 1 via addition of one further equiv of OCAs?. 相似文献
19.
Rutkowski PX Rios D Gibson JK Van Stipdonk MJ 《Journal of the American Society for Mass Spectrometry》2011,22(11):2042-2048
Electrospray ionization of actinyl perchlorate solutions in H2O with 5% by volume of dimethylformamide (DMF) produced the isolatable gas-phase complexes, [AnVIO2(DMF)3(H2O)]2+ and [AnVIO2(DMF)4]2+, where An = U, Np, and Pu. Collision-induced dissociation confirmed the composition of the dipositive coordination complexes,
and produced doubly- and singly-charged fragment ions. The fragmentation products reveal differences in underlying chemistries
of uranyl, neptunyl, and plutonyl, including the lower stability of Np(VI) and Pu(VI) compared with U(VI). 相似文献
20.
Infrared vibrational spectra,electronic structures,and formation reactions of polypyrrolic mono‐ and bis‐actinyl complexes: A relativistic DFT study 下载免费PDF全文
Xiu‐Jun Zheng Ning Qu Li‐Chun Xuan Qing‐Jiang Pan 《International journal of quantum chemistry》2017,117(13)
The development of synthetic techniques has enabled synthesis and characterization of a series of mono and bis‐uranyl complexes of octadentate polypyrrolic macrocycles such as aryl‐lined H4LAr and anthracenyl‐linked H4L, which is complemented by theoretical investigation via extending to more toxic and radioactive transuranics. The relativistic density functional theory (DFT) study has been dedicated to twelve actinyl complexes supported by the H4L ligand. The actinides include U, Np, and Pu elements, and either one or two is rendered in complexes with oxidation states of V or VI. Calculated symmetric/asymmetric An = O stretching vibrational frequencies show the decreasing trend along U, Np, and Pu, which is consistent with calculated bond orders. The hydrogen bonds between –yl endo‐oxo and remaining hydrogen atoms of pyrrolides in mononuclear complexes cause pronounced redshift of An = O vibrational frequencies compared to those in binuclear complexes, so does the reduction from hexa‐ to penta valent complexes. The electronic structures of actinyl complexes were calculated. For example, B‐ pyUVI possesses low‐lying U(5f )‐character virtual orbitals, where f (δ) and f (?) orbitals occur in low‐energy region and π‐type ones are residing further high; the σ*(U = O) and σ(U = O) orbitals are significantly split over 7 eV. The previous experimental observation that the 1:1 reactions between uranyl salts and the macrocycle tend to give a mixture of bis‐ and mono‐uranyl complexes, with bis‐ the major product, has been corroborated by computational studies of the thermodynamics of the reactions. 相似文献