13709-59-6Relevant academic research and scientific papers
Insight into the Crystalline Structure of ThF4 with the Combined Use of Neutron Diffraction, 19F Magic-Angle Spinning-NMR, and Density Functional Theory Calculations
Martel, Laura,Capelli, Elisa,Body, Monique,Klipfel, Marco,Bene?, Ondrej,Maksoud, Louis,Raison, Phillipe E.,Suard, Emmanuelle,Visscher, Lucas,Bessada, Catherine,Legein, Christophe,Charpentier, Thibault,Kovács, Attila
, p. 15350 - 15360 (2018)
Because of its sensitivity to the atomic scale environment, solid-state NMR offers new perspectives in terms of structural characterization, especially when applied jointly with first-principles calculations. Particularly, challenging is the study of actinide-based materials because of the electronic complexity of the actinide cations and to the hazards due to their radioactivity. Consequently, very few studies have been published in this subfield. In the present paper, we report a joint experimental-theoretical analysis of thorium tetrafluoride, ThF4, containing a closed-shell actinide (5f0) cation. Its crystalline structure has been revisited in the present work using powder neutron diffraction experiments. The 19F NMR parameters of the seven F crystallographic sites have been modeled using an empirical superposition model, periodic first-principles calculations, and a cluster-based all-electron approach. On the basis of the atomic position optimized structure, a complete and unambiguous assignment of the 19F NMR resonances to the F sites has been obtained.
INFRARED-TRANSPARENT GLASSES DERIVED FROM THE FLUORIDES OF ZIRCONIUM, THORIUM, AN BARIUM.
Robinson,Pastor,Turk,Devor,Braunstein,Braunstein
, p. 735 - 742 (1980)
Glasses consisting solely of high-purity ZrF//4, ThF//4, and BaF//2 have been synthesized using reactive atmosphere processing (RAP) techniques. RAP of the individual components and molten material with anhydrous HF and CCl//4 is described. The glass molds easily at 312 degree C and 1920 psi with a high-fidelity replication of the die surface. The glass is water-insoluble, unusually hard and strong, and continuously transparent from 0. 3 to 7 mu m.
Thorium Compounds with Bonds to Sulfur or Selenium: Synthesis, Structure, and Thermolysis
Rehe, David,Kornienko, Anna Y.,Emge, Thomas J.,Brennan, John G.
, p. 6961 - 6967 (2016)
Thorium chalcogenolates Th(ER)4 (E = S, Se; R = Ph, C6F5) form pyridine complexes with a variety of coordination numbers. Four compounds, (py)4Th(SPh)4, (py)3Th(SePh)4, (py)3Th(SC6F5)4, and (py)4Th(SeC6F5)4, have been isolated and characterized by spectroscopic methods and low-temperature single crystal X-ray diffraction. Two of the products, (py)4Th(SPh)4 and (py)4Th(SeC6F5)4, have classic eight coordinate A4B4 square-antiprism geometries. The SePh compound is the only seven coordinate (4Se, 3N) product, and the fluorinated thiolate is distinctive in that the structure contains two dative interactions between Th and fluoride, to give a nine coordinate (3N, 4S, 2F) structure. The EPh compounds decompose thermally to give ThE2 and EPh2, while the fluorinated compounds give primarily ThF4, E2(C6F5)2, and E(C6F5)2.
Raman scattering study of the orthorhombic-to-tetragonal phase transition of a Li3ThF7 crystal
Oliveira,Gesland,Pimenta,Moreira
, p. 9983 - 9989 (1999)
Raman spectroscopy was used to study pulled Li3ThF7 single crystals between 298 and 403 K, using six special backscattering geometries. The observed Raman bands were very broad, owing to the disorder related to the statistical occupancy of the lithium sites (with a 3/4 probability). In spite of this, the symmetry rules are well respected assuming an average model with four lithium ions per chemical formula. The spectral evolutions show a structural phase transition occurring at 368 K. After peak deconvolution, we were able to determine and attribute most of the Raman modes corresponding to each phase. The results are compatible with the proposed orthorhombic (Ccca) to tetragonal (P4/ncc) structural phase transition, whose ferroelastic nature would be responsible for the appearance of an ordered microcracking pattern in this crystal. 1999 The American Physical Society.
Decomposition Pressure and Thermodynamic Stability of Thorium Oxyfluoride
Lau, K. H.,Hildenbrand, D. L.
, p. 3768 - 3770 (1989)
The decomposition pressure of the oxyfluoride-phase ThOF2(s) was measured by the torsion-effusion method over the range 1100-1250 K.The material vaporizes incongruently to yield ThF4(g) and ThO2(s).Vapor composition was verified by mass spectrometry and vapor molecular weight measurements.A small effusion orifice-area dependence indicates a slight kinetic barrier to the incongruent vaporization process.Derived equilibrium data show that ThOF2(s) is only marginally stable, with a Gibbs energy of formation of about 8 kJ mol-1 from ThF4(s) and ThO2(s).
Synthesis and nanoscale characterization of (NH4) 4ThF8 and ThNF
Silva, G.W. Chinthaka,Yeamans, Charles B.,Cerefice, Gary S.,Sattelberger, Alfred P.,Czerwinski, Kenneth R.
, p. 5736 - 5746 (2009)
Synthesis of (NH4)4ThF8 by a solid state reaction of ThO2 and NH4HF2 and the formation of ThNF by ammonolysis of (NH4)4ThF8 and ThF4 under differ
Synthetic Strategies for the Synthesis of Ternary Uranium(IV) and Thorium(IV) Fluorides
Klepov, Vladislav V.,Felder, Justin B.,Zur Loye, Hans-Conrad
, p. 5597 - 5606 (2018)
A series of new U(IV) and Th(IV) fluorides, Na7U6F31 (1), NaUF5 (2), NaU2F9 (3), KTh2F9 (4), NaTh2F9 (5), (H3O)Th3F13
Development of a YF3:ThF4 membrane for the possibility of determining fluoride
Gnanasekar, K. I.,Jayaraman, V.,Lakshmi K, Usha,Lakshmigandhan, I.,Ravindranath, Nair Afijith
, (2021)
Preparation of yttrium substituted thorium fluoride (YTF) solid solution, YxTh1?xF4?x (x = 0 – 0.15) by fluorinating a stoichiometric ratio of yttria (Y2O3) and thoria (ThO2) with ammonium hydrogen difluoride (NH4HF2) was acheived. The maximum solubility of YF3 in ThF4 was observed to be 15 mol %. All three compositions of YxTh1?xF4?x (x = 0 – 0.15) solid solution showed an enhanced ionic conductivity over ThF4. 5 mol % yttrium substituted ThF4 (5-YTF) had the highest ionic conductivity, almost 2 orders higher than ThF4. The F? ion selective electrode was designed and tested for estimation of fluoride ion in solution (10?1M to 10?5 M). 5-YTF had the highest sensitivity of 40.0 ± 4 mV/decade in the linear range of 10?1 M to 10?4 M. All the three sensors compositions 5, 10 and 15-YTF have sub Nerstian behavior which is attributed to strong OH? ion interefenece.The results were compared with commercial fluoride ISE (Eu: LaF3).
Stabilization of Th3+ ions into mixed-valence thorium fluoride
Dubois, Marc,Dieudonn, Belto,Mesbah, Adel,Bonnet, Pierre,El-Ghozzi, Malika,Renaudin, Guillaume,Avignant, Daniel
, p. 220 - 226 (2011)
The unusual oxidation state 3 of the thorium has been stabilized into a lithium containing non-stoichiometric mixed-valence (III/IV) thorium fluorinated phase with formula Li2xTh12F50 (05.5Ce 12F50 one, the structure of which has been determined from the combined single-crystal X-ray diffraction and high resolution synchrotron powder diffraction. In these phases, the Li+ ions can be divided into two groups and are located either in locked positions or in open channels of the three dimensional framework. The amount of Li+ ions in open channels can be variable, so that the afore mentioned single phase may be considered as an insertion compound. The Li+ insertion is accompanied by the simultaneous reduction of a part of the Th4 ions, resulting in a mixed-valence III/IV thorium fluoride. The electrochemical insertion of Li+ ions into the open channels of the host matrix has been carried out at 60 °C, using an alkylcarbonate PCLiClO4 1 M electrolyte. The Li+ and Th3 contents, both in the starting composition and the Li+ inserted ones, were investigated by high resolution solid state 7Li NMR and EPR, respectively.
Joint solubility of PuF3 and CeF3 in ternary melts of lithium, thorium, and uranium fluorides
Lizin, A. A.,Tomilin, S. V.,Osipenko, A. G.,Kormilitsyn, M. V.,Nezgovorov, N. Yu.,Ignat'Ev, V. V.
, p. 36 - 42 (2015)
Joint solubility of PuF3 and CeF3 in melts of the molar composition 78LiF-7ThF4-15UF4 and 72.5LiF-7ThF4-20.5UF4 in the temperature range 550°-800°C was studied. Anhydrous PuF3 and CeF3 spiked with 144Ce, and also anhydrous ThF4 were synthesized. Isothermal saturation method was used for studying the solubility of pressed PuF3 and CeF3 pellets in these melts in an inert (argon) atmosphere. The dependence of the joint solubility of PuF3 and CeF3 on the melt temperature was determined.
