New tools for calibrating diffraction setups

New calibration tools in the pyFAI suite for processing scattering experiments acquired with area detectors are presented. These include a new graphical user interface for calibrating the detector position in a scattering experiment performed with a fixed large area detector, as well as a library to be used in Jupyter notebooks for calibrating the motion of a detector on a goniometer arm (or any other moving table) to perform diffraction experiments.

Structural stability and thermoelectric performance of high quality synthetic and natural pyrites (FeS2)

Single crystalline pyrite of high quality reveals good thermal- and bad electrical conductivities resulting in poor thermoelectric performance.

Structural and thermodynamic investigation of AnIVLI(O)HOPO

For the first time, capillary electrophoresis coupled with inductively coupled plasma mass spectrometry has been used to determine the stability constants of Pu^IV with the multidentate hydroxypyridinonate chelating agents LI(O)HOPO in 0.1 M NaNO₃ solution, p_cH = 1.395 at 25 °C through competition with the NTA ligand.

Thermische Zersetzung und Lösungskalorimetrie von Ammoniumneodymchloriden/Thermal Decomposition and Solution Calorimetry of Ammonium Neodymium Chlorides

The thermodynamical data of ammonium neodymium chlorides (NH4)2NdCl5 and NH4Nd2Cl7 were derived by the determination of their decomposition equilibria by total pres­sure measurements. Moreover, solution calorimetry was applied. The enthalpies of formation of these phases were calculated from their heats of solution and from the enthalpies of formation and the heats of solution of NdCl3 and NH4Cl.

Data by total pressure measurement:

ΔH°B((NH4)2NdCl5,f,298) = - 412,5 ± 3,6 kcal/mol;

S°((NH4)2NdCl5 f 298) = 80,1 ± 5,8 cal/K · mol;

ΔH°B(NH4Nd2Cl7,f,298) = -579,5 ± 3,5 kcal/mol;

S°(NH4Nd2Cl7,f,298) 101,8 ± 5,6 cal/K mol.

Data by solution calorimetry:

ΔH°B(NdCl3,f,298) = -251,2 ± 0,7 kcal/mol;

ΔH°B((NH4)2NdCl5,f,298) = -405,5 ± 1,0 kcal/mol;

ΔH°B(NH4Nd2Cl7,f, 298) = -576,8 ± 1,7 kcal/mol.

Thermochemisches und kalorisches Verhalten von NdAl3Cl12 / Thermochemical and Calorical Behaviour of NdAl3Cl12

The thermodynamical data of solid and gaseous aluminium neodymium chloride have been obtained by determination of the decomposition equilibria (of solid) from total pressure measurements and chemical transport reactions (gaseous). The melting diagram was determined by DTA. The enthalpy of formation of the solid phase was calculated from their heats of solution and from the enthalpies of formation and the heats of solution of NdCl3 and AlCl3.

Data by total pressure measurement:

ΔH°B |(NdAl3Cl12,f,298) = -749,6 ± 2,5 kcal/mol; S°(NdAl3Cl12,f,298) = 118,2 ± 3,0 cal/K·mol.

Data by solution calorimetry: ΔH°B(NdAl3Cl12,f,298) = -748,6 ± 1,3 kcal/mol.

Data by chemical transport:

ΔH°B(NdAl3Cl12,g,298) = -701,5 ± 3,0 kcal/mol; S°(NdAl3Cl12,g,298) = 215,0 ± 4,0 cal/K-mol.

Thermische Zersetzung und Lösungskalorimetrie von Ammoniumneodymbromiden / Thermal Decomposition and Solution Calorimetry of Ammonium Neodymium Bromides

The thermal decomposition equilibria of ammonium neodymium bromides (NH4)3NdBr6, (NH4)2NdBr5 and NH4Nd2Br7 have been investigated by total pressure measurements. The thermodynamical data of these solid phase complexes have been derived from the decomposition functions. The standard enthalpies of solution in 4N HBr (aq.) of (NH4)3NdBr6, (NH4)2NdBr5, NH4Nd2Br7, NdBr3 and Nd2O3 were measured. On the basis of these values and tabulated data, the standard enthalpies at 298 K of the ammonium neodymium bromides were derived and compared with the results obtained from the total pressure measurements.

Data by total pressure measurement: ΔH°B((NH4)3 NdBr6,f,298) = -399,1 ± 4,9 kcal/mol; S°((NH4)3NdBr6,f,298) = 153,4 ± 7,4 cal/K.mol; ΔH°B((NH4)2NdBr5,f,298) = -343,0 ± 4,4 kcal/mol; S°((NH4)2,NdBr5,f,298) = 109,9 ± 6,8 cal/K.mol; ΔH°B(NH4Nd2Br7,f,298) = -484,0 ± 5,1 kcal/mol; S°(NH4Nd2Br7,f,298) = 127,9 ± 6,6 cal/K.mol.

Data by solution calorimetry: ΔH°B(NdBr3,f,298) = -208,7 ± 1,6 kcal/mol; ΔH°B((NH4)3- NdBr6,f,298) = -404,8 ± 2,7 kcal/mol; ΔH°B((NH4)2NdBr5,f,298) = -344,2 ± 2,4 kcal/mol; ΔH°B(NH4Nd2Br7,f,298) = -482,7 ± 3,7 kcal/mol.

Thermochemische Untersuchungen zum ternären System Bi/Se/O. II. Das Teilsystem Bi2O3– SeO2/Thermochemical Investigations on the Ternary System Bi/Se/O.II.The Binary System Bi2O3–SeO2

We describe the existence of six thermodynamically stable phases on the binary line Bi2O3- SeO2 at room temperature: Bi12SeO20, Bi10Se2O19, Bi16Se5O34, Bi2SeO5, Bi2Se3O9 and Bi2Se4O11. At higher temperature we optained evidence for Bi20Se3O36 and Bi4SeO8. The decomposition pressures were measured for all phases in a membrane zero manometer and the enthalpy of formation and the standard entropy was determined. The phase barogram and phase diagram followed from total pressure measurements and differential thermoanalysis. The standard enthalpies of formation of all phases were also derived from solution calorimetry. The necessary data of transitions on molar enthalpies were obtained by DSC- and Cp-measurements.

Thermische Zersetzung und Lösungskalorimetrie von Ammoniumeuropiumchloriden / Thermal Decomposition and Solution Calorimetry of Ammonium Europium Chlorides

The thermal decomposition equilibria of ammonium europium chlorides (NH4)3EuCl6, (NH4)2EuCl5 and NH4Eu2Cl7 have been investigated by total pressure measurements in a membrane zero manometer. The thermodynamic data of these solid phases have been derived from the decomposition functions. The standard enthalpies of solution in 4n HCl (aq.) of (NH4)3EuCl6, (NH4)2EuCl5, NH4Eu2Cl7, EuCl3 and Eu2O3 were measured. On the basis of these values and tabulated data, the standard enthalpies at 298 K of the ammonium europium chlorides were derived and compared with the obtained results from the total pressure measurements.

Calorimetrie an Yttriumtrihalogeniden und Yttriumoxidhalogemden / Calorimetry of Yttrium Trihalides and Yttrium Oxyhalides

The heats of solution of Yttrium, YOCL, YOBr, YOI, YCl3, YBr3, YI3 and Y2O3 were determined in 4n HX. From those the enthalpies of formation of Yttrium Trihalides YX3 and Yttrium Oxyhalides YOX at 298 K were derived:

ΔHB 0(YCl3,f,298) = -240.4 ± 0.6 kcal/mol, ΔHB 0(YBr3,f,298) = -202.1 ± 1.5 kcal/mol,

ΔHB 0(YI3,f ,298) = -147.0 ± 1.7 kcal/mol, ΔHB 0(YOClf,298) = -240.2 ± 1.0 kcal/mol,

ΔHB 0(YOBrf,298) = -229.7 ± 2.0 kcal/mol, ΔHB 0(YOIf ,298) = -208.8 ± 2.0 kcal/mol.

Thermische Zersetzung und Lösungskalorimetrie von Ammoniumsamariumchloriden/Thermal Decomposition and Solution Calorimetry of Ammonium Samarium Chlorides

We determined the decomposition equilibria of ammonium samarium chlorides (NH4)2SmCl5 and NH4Sm2Cl7 by total pressure measurements and derived their thermody­ namical data from the decomposition functions. The enthalpies of formation were compared with the results of the solution calorimetry. The heats of solution of all solid phases in the system SmCl3-NH4Cl and of Sm2O3 were measured in 4n HCl. The enthalpies of formation of ammonium samarium chlorides were derived from the enthalpies of formation of SmCl3 and of NH4Cl and their heats of solution.

Data by total pressure measurement

ΔH°B((NH4)2SmCl5,f,298) =-407,7 ± 2,9 kcal/mol;

S0((NH4)2SmCl5,f,298) = 84,0 ± 4,5 cal/K-mol;

ΔH°B((NH4)Sm2Cl7,f,298) = -576,8 ± 3,4 kcal/mol;

S°(NH4Sm2Cl7,f,298) = 98,1 ± 5,5 cal/K-mol.

Data by solution calorimetry

ΔH°B(SmCl3,f,298) = -248,1 ± 0,8 kcal/mol;

ΔH°B((NH4),SmCl5,f,298) = -404 ,3 ± 1,1 kcal/mol;

ΔH°B(NH4Sm9Cl7,f,298)= -572,3 ± 1,8 kcal/mol.

Untersuchungen zum ternären System Bi/Te/O, III. Bestimmung thermodynamischer Daten der ternären Verbindungen/Investigations on the Ternary System Bi/Te/O,III. Determination of Thermodynamic Data of Ternary Compounds

The phase relations in the ternary system Bi/Te/O have been determined in previous studies by solid state reactions. Thermodynamical data have now been obtained for the pertinent equilibria. The heats of solution of Bi2O3, Bi12TeO20, Bi10Te2O19, Bi16Te5O34, Bi2TeO5, Bi2Te2O7, Bi2Te4O11 and TeCl4 were determined in 4N HCl. From these the enthalpies of formation of bismuth tellurites at 298 K have been derived:

⊿H°b (Bi12TeO20, f, 298) = -901,6 ± 8 kcal/mol,

⊿H°b (Bi10Te2O19, f, 298) = -856,1 ± 9 kcal/mol,

⊿H°b (Bi16Te5O34, f, 298) = -1519,5 ± 17 kcal/mol,

⊿H°b (Bi2TeO5, f, 298)= -222,8 ± 3 kcal/mol,

⊿H°b (Bi2Te2O7, f, 298)= -299,4 ± 4 kcal/mol,

⊿H°b (Bi2Te4O11, f, 298)= -448,2 ± 7 kcal/mol.

Calorimetrie an Ammoniumyttriumhalogeniden / Calorimetry of Ammonium Yttrium Halides

The heat of solution of all solid phases in the system YX3-NH4X with X = Cl, Br, I in 4n HX was investigated. The enthalpies of formation of the ammonium yttrium halides are derived from the enthalpies of formation of Y X3 and of NH4X and their heats of solution in An HX:

ΔHB 0(NH4Y2Cl7,f,298) = -561,5 ± 1,7 kcal/mol, ΔHB 0((NH4)3 YCl6,f,298) = -474,5 ± 1,3 kcal/mol,

ΔHB 0((NH4)3YBr6,f,298) = -400,8 ± 2,6 kcal/mol, ΔHB 0((NH4)3YI6,f,298) = -291,9 ± 3,0 kcal/mol.

Untersuchungen zum quasibinären System Bi2Te3/BiCl3/Investigations on the Pseudobinary System Bi2Te3/BiCl3

The phase diagram of the pseudobinary sytem Bi2Te3/BiCl3 was investigated by DTA, total pressure measurements, and X-ray phase analysis. Only BiTeCl exists as a ternary phase in this system. The compound melts incongruently at 430 °C. The heat of formation and the standard entropy of BiTeCl were calculated from vapor pressure data:

ΔH°B (BiTeCl, f, 298) = (-39,5 ± 1,6) kcal/mol; S° (BiTeCl, f, 298) = (34,4 ± 2,7) cal/K· mol.

The heat of formation of BiCl3 was determined on the basis of the heat of solution of BiCl3 and Bi2O3, and the heat of formation of Bi2O3: ΔH°B (BiCl3, f, 298) = (-95,9 ± 0,9) kcal/mol.

Neonatal murine macrophages show enhanced chemotactic capacity upon toll-like receptor stimulation

BACKGROUND

The neonatal surgical patient is threatened by exuberant inflammatory reactions. Neonatal macrophages are key players in this process. We investigated the ability of neonatal macrophages to initiate a local inflammatory reaction upon exposure to different bacterial or viral ligands to toll-like receptors (TLRs).

METHODS

Peritoneal wash outs from neonatal (<24 h) and adult (42 days) C57BL/6J mice were gained by peritoneal lavages. In a first set of experiments, macrophages were purified and stimulated for 6 h by four different TLR ligands. mRNA was extracted for transcriptome analysis. In a second set of experiments, lipopolysaccharide was applied into peritoneal cavities. After 6 h of incubation, the cellular composition of the inflamed cavities was evaluated by cytological staining as well as chipcytometry.

RESULTS

Neonatal murine peritoneal macrophages differed significantly in the expression of pro- and anti-chemotactic genes. Functional assignment of these genes revealed enhanced chemotactic potential of neonatal macrophages and was confirmed by a higher influx of pro-inflammatory cells into neonatal peritoneal cavities.

CONCLUSION

Neonatal peritoneal macrophages demonstrated an enhanced chemotactic potential upon stimulation with four TLR ligands. This was associated with an increased influx of inflammatory cells to the peritoneal cavity. This might contribute to the strong inflammatory responses of neonates and preterms.

GATA1s induces hyperproliferation of eosinophil precursors in Down syndrome transient leukemia

Transient leukemia (TL) is evident in 5–10% of all neonates with Down syndrome (DS) and associated with N-terminal truncating GATA1-mutations (GATA1s). Here we report that TL cell clones generate abundant eosinophils in a substantial fraction of patients. Sorted eosinophils from patients with TL and eosinophilia carried the same GATA1s-mutation as sorted TL-blasts, consistent with their clonal origin. TL-blasts exhibited a genetic program characteristic of eosinophils and differentiated along the eosinophil lineage in vitro. Similarly, ectopic expression of Gata1s, but not Gata1, in wild-type CD34⁺-hematopoietic stem and progenitor cells induced hyperproliferation of eosinophil promyelocytes in vitro. While GATA1s retained the function of GATA1 to induce eosinophil genes by occupying their promoter regions, GATA1s was impaired in its ability to repress oncogenic MYC and the pro-proliferative E2F transcription network. ChIP-seq indicated reduced GATA1s occupancy at the MYC promoter. Knockdown of MYC, or the obligate E2F-cooperation partner DP1, rescued the GATA1s-induced hyperproliferative phenotype. In agreement, terminal eosinophil maturation was blocked in Gata1^Δe2 knockin mice, exclusively expressing Gata1s, leading to accumulation of eosinophil precursors in blood and bone marrow. These data suggest a direct relationship between the N-terminal truncating mutations of GATA1 and clonal eosinophilia in DS patients.

Impact of enzymatic tissue disintegration on the level of surface molecule expression and immune cell function

Immunological characterization of immune cells that reside in specific anatomic compartments often requires their isolation from the respective tissue on the basis of enzymatic tissue disintegration. Applying enzymatic digestion of primary splenocytes, we evaluated the impact of collagenase and dispase, two enzymes that are commonly used for the liberation of immune cells from tissues, on the detectability of 48 immunologically relevant surface molecules that are frequently used for flow cytometric identification, isolation, and characterization of immune cell subsets. Whereas collagenase treatment had only minor effects on surface expression of most molecules tested, dispase treatment considerably affected antibody-mediated detectability of the majority of surface markers in subsequent FACS analyses. This effect was long lasting and, in case of high-dose dispase treatment, evident for the majority of surface molecules even after 24 h of in vitro culture. Of note, high-dose dispase treatment not only affected surface expression of certain molecules but also impaired antigen-specific proliferation of CD4(+) and CD8(+) T cells. Together, our data indicate that enzymatic tissue disintegration can have profound effects on the expression of a variety of cell-surface molecules with direct consequences for phenotypic analysis, FACS- and MACS-based target cell isolation, and immune cell function in cell culture experiments.

EXAFS and XRD investigations of zeunerite and meta-zeunerite

In this paper EXAFS was used to determine bond lengths in the structures of zeunerite and meta-zeunerite. The atomic distances between heavy and light scatterers observed using EXAFS in meta-zeunerite deviate approximately 0.1 Å from literature data of single-crystal X-ray diffraction measurements. Because this difference is significant higher than the error limits of EXAFS measurements, the complete crystal structure of meta-zeunerite, Cu[UO2AsO4]2·8 H2O, is revised by X-ray structure analysis. The bond length determinations by EXAFS and the revised XRD data agree within the experimental error limits. In this study EXAFS spectroscopy has proven to be an useful tool for determining precise local bond lengths in the environment of heavy atoms. Moreover, the crystal structure of zeunerite, Cu[UO2AsO4]2·12 H2O, hitherto not been described in the literature, was investigated. Reflex broadening effects and intergrowth relationship between zeunerite and meta-zeunerite show that meta-zeunerite grows in nature due to dehydration of zeunerite. The structural transition from zeunerite to meta-zeunerite is connected with a change in the uranyl arsenate layer arrangement and the crystal water content.

EXAFS investigation of uranium(VI) complexes formed at Bacillus cereus and Bacillus sphaericus surfaces

Uranium(VI) complex formation at vegetative cells and spores of Bacillus cereus and Bacillus sphaericus was studied using uranium L II-edge and L III-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. A comparison of the measured equatorial U-O distances and other EXAFS structural parameters of uranyl species formed at the Bacillus strains with those of the uranyl structure family indicates that the uranium is predominantly bound as uranyl complexes with phosphoryl residues.

Characterization of U(VI)-Acidithiobacillus ferrooxidans complexes using EXAFS, transmission electron microscopy, and energy-dispersive X-ray analysis

We used a combination of Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy, Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray (EDX) analysis to conduct molecular scale studies on U(VI) interaction with three recently described eco-types of Acidithiobacillus ferrooxidans. On the basis of the information obtained by using these methods, we concluded that uranyl phosphate complexes were formed by the cells of the three eco-types studied. The uranium accumulated by A. ferrooxidans cells was located mainly within the extracellular polysaccharides, and on the cell wall. Smaller amounts were also observed in the cytoplasm.

EXAFS structural analysis of aqueous uranium(VI) complexes with lignin degradation products

Uranium LIII-edge extended X-ray absorption fine structure (EXAFS) analysis was carried out on aqueous uranium(VI) complexes with monomeric intermediates of the natural wood-degradation process such as protocatechuic acid (3,4-dihydroxybenzoic acid), catechol (2-hydroxyphenol), pyrogallol (1,2,3-trihydroxybenzol), and vanillic acid (4-hydroxy-3-methoxybenzoic acid). The structural parameters of the 1:1 complexes with protocatechuic acid and vanillic acid in weakly acidic solution indicate that the carboxylic group coordinates the uranyl cation in a bidentate mode in the equatorial plane. Based on the identical structural parameters observed for protocatechuic acid, catechol and pyrogallol in alkaline media, we conclude that the coordination with uranium occurs via the neighboring OH groups of the phenols under formation of a five-membered ring.

Structure of uranium sorption complexes at montmorillonite edge sites

Extended X-ray absorption fine structure (EXAFS) spectroscopy at the uranium LIII-edge was used for determining the structural environment of aqueous uranyl sorbed onto montmorillonite. The study reveals that uranyl uptake at pH ∼5-∼7 and at an initial uranyl concentration of 5×10−5M takes place at amphoteric surface hydroxyl sites as inner-sphere complex. The measured bond distances between uranium and the equatorial oxygen atoms are in the range of 2.34 Å and 2.37 Å indicating an inner-sphere coordination. At ∼3.4 Å the presence of a U-Al backscattering pair was determined. This backscattering pair indicates that the binding of the uranyl unit to amphoteric surface hydroxyl sites occurs preferred as a bidentate inner-sphere complex on aluminol groups.

EXAFS analyses of technetium(I) carbonyl complexes – stability studies in solutions

EXAFS analyses were successfully used to determine the structure of Re and Tc carbonyl thioether complexes in solid and liquid samples. In connection with chromatographic and mass spectrometric methods the behaviour of Tc carbonyl dithioether complexes in aqueous solution was studied. It was found that complexes containing a bidentate thioether ligand are able to react with water by exchange of the chloride ion, which results in the formation of a cationic complex. As expected, the exchange proceeds faster at the n.c.a. level because of concentration differences.

Speciation of technetium and rhenium complexes byin situXAS-electrochemistry

A spectro-electrochemical cell was developed in order to study the speciation of radio-elements in thermodynamic unstable redox states usingin situXAS spectroscopy. This cell was used for the speciation of Re and Tc complexes in chloride media. Experiments on Re were carried out with the aim to validate the functionality of the experimental set-up. During electro-reduction of Re(VII) in HCl media, EXAFS and XANES studies were performed in order to reveal the formation of chloro-oxygenated compounds of Re(IV). The speciation of technetium in aqueous solutions of deep geological deposits for radioactive waste is important to predict its mobility under reducing conditions. XANES spectra showed that electro-reduction of Tc(VII) in chloride media leads to a position ofK-edge absorption which agrees with a Tc(IV)/Tc(III) mixture.

An EXAFS and TRLFS study of the sorption of trivalent actinides onto smectite and kaolinite

The structure parameters of the Am3+ aquo ion and of Am(III) sorbed onto smectite and kaolinite at varying pH are analyzed using EXAFS. An Am-O distance of 2.47-2.49Å is found and a coordination number of 8-9 oxygen atoms is observed for the Am3+ and its hydration sphere. Combined TRLFS (Cm(III)) and EXAFS (Am(III)) results show that An(III) sorbs onto smectite at pH 4, forming an outer-sphere complex and retains its complete primary hydration sphere. With increasing pH, inner-sphere sorption onto smectite and kaolinite occurs. The overall number of oxygen atoms coordinating the actinide ion remains about the same at pH 6, with four water molecules being replaced by oxygen atoms from the mineral surface during inner-sphere complex formation. The coordination number of sorbed Am(III) at pH 8 exhibits an apparent decrease, which may be affected by the formation of ternary OH-/Am/clay mineral surface species.

Interaction mechanisms of bacterial strains isolated from extreme habitats with uranium

This paper summarizes the effect of pH on the speciation and cellular localization of uranium bound by bacterial strains isolated from the S15 deep-well montoring site, located at the Siberian radioactive subsurface depository Tomsk-7, Russia. Microbiological methods in combination with extended X-ray absorption fine structure (EXAFS) spectroscopy, transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX) were applied. EXAFS analysis showed that the cells of the two isolates, Microbacterium oxydans S15-M2 and Sphingomonas sp. S15-S1, precipitate U(VI) as m-autunite-like phase at pH 4.5, probably due to the release of inorganic phosphate from the cells as result of the microbial metabolism. However, at pH 2 uranium formed complexes with organically bound phosphates of the cell surface. The results of the EXAFS studies corroborate those found using TEM and EDX analysis. Hypotheses explaining the different coordination chemistry of uranium to bacteria as a function of pH of uranium solution in terms of solubility of m-autunite and/or microbial activity are discussed.

Uranyl Coordination in Ionic Liquids: The Competition between Ionic Liquid Anions, Uranyl Counterions, and Cl-Anions Investigated by Extended X-ray Absorption Fine Structure and UV−Visible Spectroscopies and Molecular Dynamics Simulations

The first coordination sphere of the uranyl cation in room-temperature ionic liquids (ILs) results from the competition between its initially bound counterions, the IL anions, and other anions (e.g., present as impurities or added to the solution). We present a joined spectroscopic (UV-visible and extended X-ray absorption fine structure)-simulation study of the coordination of uranyl initially introduced either as UO2X2 salts (X-=nitrate NO3-, triflate TfO-, perchlorate ClO4-) or as UO2(SO4) in a series of imidazolium-based ILs (C4mimA, A-=PF6-, Tf2N-, BF4- and C4mim=1-methyl-3-butyl-imidazolium) as well as in the Me3NBuTf2N IL. The solubility and dissociation of the uranyl salts are found to depend on the nature of X- and A-. The addition of Cl- anions promotes the solubilization of the nitrate and triflate salts in the C4mimPF6 and the C4mimBF4 ILs via the formation of chloro complexes, also formed with other salts. The first coordination sphere of uranyl is further investigated by molecular dynamics (MD) simulations on associated versus dissociated forms of UO2X2 salts in C4mimA ILs as a function of A- and X- anions. Furthermore, the comparison of UO2Cl(4)2-, 2 X- complexes with dissociated X- anions, to the UO2X2, 4 Cl- complexes with dissociated chlorides, shows that the former is more stable. The case of fluoro complexes is also considered, as a possible result of fluorinated IL anion's degradation, showing that UO2F42- should be most stable in solution. In all cases, uranyl is found to be solvated as formally anionic UO2XnAmClp2-n-m-p complexes, embedded in a cage of stabilizing IL imidazolium or ammonium cations.