Xi:Irritant;
7681-82-5Relevant articles and documents
Static observation of the interphase between NaBH4 and LiI during the conversion reaction
Hihara, Takehiko,Miyagawa, Reina,Miyazaki, Reona,Onishi, Keita
, (2021/08/10)
To determine the synthesis conditions for NaI–NaBH4–LiI solid solutions in a single phase, the conversion reaction of NaBH4 ?+ ?LiI → NaI ?+ ?LiBH4 was investigated by preparing mixed pellets of NaBH4/LiI. The extent of the reaction was investigated under different reaction temperatures and pressures. Although it was not possible to completely suppress the conversion reaction in this study, the low temperature and high-pressure conditions were shown to be favorable to avoid the presence of LiBH4. A significant point is that the conversion reaction was investigated in a static condition in the form of pellets, whereas most of the metal borohydride-halide composites have been fabricated by ball-milling. The microstructure of NaBH4/LiI mixed pellets at different ageing times was observed by scanning electron microscope (SEM), Auger electron spectroscopy (AES), wavelength dispersive X-ray spectroscopy (WDS) and time of flight secondary ion mass spectroscopy (ToF-SIMS). The analysis revealed that the reaction interphase between NaBH4 and LiI occurs in the order of LiI/NaI/LiBH4/NaBH4. It was clearly confirmed that the growth of the NaI layer continued with time even at room temperature. In conjunction with the array of the interphase, the diffusion of Na+ in LiBH4 appears to be a necessary condition for the growth of the NaI layer. The present results suggest that a detailed investigation of the conversion reaction between other metal borohydrides and halides (for example, CeCl3/LiBH4, ZrCl4/KBH4, etc.) in the static condition would likely reveal the diffusion of the new ions in the existing compounds.
Ion Exchange of Layered Alkali Titanates (Na2Ti3O7, K2Ti4O9, and Cs2Ti5O11) with Alkali Halides by the Solid-State Reactions at Room Temperature
Ogawa, Makoto,Saothayanun, Taya Ko,Sirinakorn, Thipwipa Tip
, p. 4024 - 4029 (2020/04/08)
Ion exchange of layered alkali titanates (Na2Ti3O7, K2Ti4O9, and Cs2Ti5O11) with several alkali metal halides surprisingly proceeded in the solid-state at room temperature. The reaction was governed by thermodynamic parameters and was completed within a shorter time when the titanates with a smaller particle size were employed. On the other hand, the required time for the ion exchange was shorter in the cases of Cs2Ti5O11 than those of K2Ti4O9 irrespective of the particle size of the titanates, suggesting faster diffusion of the interlayer cation in the titanate with lower layer charge density.
Crystal and Electronic Structures of A2NaIO6Periodate Double Perovskites (A = Sr, Ca, Ba): Candidate Wasteforms for I-129 Immobilization
Dixon Wilkins, Malin C.,George, Jonathan,Hyatt, Neil C.,Kim, Eunja,Kirk, Cameron,Knight, Kevin S.,Montoya, Eduardo,O'Sullivan, Sarah E.,Sun, Shi-Kuan,Weck, Philippe F.
, p. 18407 - 18419 (2020/12/23)
The synthesis, structure, and thermal stability of the periodate double perovskites A2NaIO6 (A= Ba, Sr, Ca) were investigated in the context of potential application for the immobilization of radioiodine. A combination of X-ray diffraction and neutron diffraction, Raman spectroscopy, and DFT simulations were applied to determine accurate crystal structures of these compounds and understand their relative stability. The compounds were found to exhibit rock-salt ordering of Na and I on the perovskite B-site; Ba2NaIO6 was found to adopt the Fm-3m aristotype structure, whereas Sr2NaIO6 and Ca2NaIO6 adopt the P21/n hettotype structure, characterized by cooperative octahedral tilting. DFT simulations determined the Fm-3m and P21/n structures of Ba2NaIO6 to be energetically degenerate at room temperature, whereas diffraction and spectroscopy data evidence only the presence of the Fm-3m phase at room temperature, which may imply an incipient phase transition for this compound. The periodate double perovskites were found to exhibit remarkable thermal stability, with Ba2NaIO6 only decomposing above 1050 °C in air, which is apparently the highest recorded decomposition temperature so far recorded for any iodine bearing compound. As such, these compounds offer some potential for application in the immobilization of iodine-129, from nuclear fuel reprocessing, with an iodine incorporation rate of 25-40 wt%. The synthesis of these compounds, elaborated here, is also compatible with both current conventional and future advanced processes for iodine recovery from the dissolver off-gas.
Multistep soft chemistry method for valence reduction in transition metal oxides with triangular (CdI2-type) layers
Blakely, Colin K.,Bruno, Shaun R.,Poltavets, Viktor V.
supporting information, p. 2797 - 2800 (2014/03/21)
Transition metal (M) oxides with MO2 triangular layers demonstrate a variety of physical properties depending on the metal oxidation states. In the known compounds, metal oxidation states are limited to either 3+ or mixed-valent 3+/4+. A multistep soft chemistry synthetic route for novel phases with M2+/3+O2 triangular layers is reported.
Origin of the thermal desorption peaks of gases in NaI above 180°C
Sofronov,Kudin,Voloshko, A. Yu.,Kudin,Shishkin
, p. 1314 - 1318 (2010/03/25)
We analyze the origin of the water desorption peaks in NaI above the temperature stability range of the crystalline hydrate NaI ? 2H 2O. The two water desorption peaks at t ≥ 180°C are shown to arise from the decomposition of aqua complexes bas
Chemical synthesis of aluminum nitride nanorods in an autoclave at 200 °C
Fu, Li,Xu, Liqiang,Duan, Junling,Li, Ting,Yang, Lishan,Qian, Yitai
, p. 622 - 623 (2011/04/21)
Hexagonal phase aluminum nitride (AlN) nanorods have been prepared via a chemical reaction from Al, I2, and NaN3 in an autoclave at 200°C. Electron microscopy investigations show that the nanorods have diameters ranging from 50 to 100nm and lengths up to several micrometers. Thermal gravimetric analysis reveals that the sample has good thermal stability below 600°C, and room-temperature photoluminescence (PL) of the sample shows a strong emission peak centered at 397 nm. Copyright
METHODS FOR SYNTHESIZING AMMONIA BORANE
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Page/Page column 4; 11; 6, (2008/06/13)
Methods of synthesizing ammonia borane are provided. The methods comprise reacting at least one amine borane with ammonia such that ammonia borane is produced. Ammonia borane has a chemical formula Of NH3-BH3 and provides a good source of storage hydrogen making it useful in a variety of applications including a potential hydrogen source for fuel cells. The methods can further comprise separating the ammonia borane from the other products of the reaction. Exemplary methods can produce ammonia borane having purity greater than about 90 percent. In further examples, the methods can produce ammonia borane having purity greater than about 95 percent or greater than about 99 percent.
Sm2O2I - A new mixed-valence samarium(II,III) oxide halide
Ryazanov, Mikhail,Hoch, Constantin,Mattausch, Hansjuergen,Simon, Arndt
, p. 2385 - 2388 (2008/10/09)
Dark red single crystals of Sm2O2I were obtained from a reaction of SmI2 (in the presence of SmOI) and Na in a sealed tantalum ampoule at 650 °C. The title compound crystallizes in the monoclinic system (C2/m, Z = 4, a = 12.639(2), b = 4.100(1), c = 9.762(3) A, β = 117.97(2)°). The structure consists of corrugated [Sm 2+Sm3+(O2-)2]+ layers of edge and vertex-connected Sm4O tetrahedral units with I- anions separating the layers.
New synthesis route to and physical properties of lanthanum monoiodide
Ryazanov, Mikhail,Kienle, Lorenz,Simon, Arndt,Mattausch, Hansjuergen
, p. 2068 - 2074 (2008/10/09)
A fast procedure to produce Lal by reduction of Lal2 or Lal 3 in a Na melt under argon at 550°C is given. The structural studies performed by means of powder X-ray diffraction as well as transmission electron microscopy are consistent with previous single-crystal results. Measurements of the electrical resistance on polycrystalline samples reveal metallic behavior for Lal in the range 10-300 K. Upon cooling, a small maximum in the resistivity has been observed at 67 K. This anomaly disappears upon heating a sample, however, yielding a hysteresis in ρ(T) above 70 K. From the Pauli susceptibility, an electron density of states at the Fermi level of about 0.3 eV-1·formula unit-1 has been estimated, as compared with a value of 1.0 eV-1·formula unit-1 derived from ab initio LMTO band structure calculations.
The synthesis of a sterically hindered samarium(II) bis(amidinate) and conversion to its homoleptic trivalent congener
Cole, Marcus L.,Junk, Peter C.
, p. 2695 - 2697 (2007/10/03)
The first divalent samarium bis(amidinate) has been prepared and aspects of its novel chemistry, including the preparation of a sterically hindered homoleptic Sm(III) tris(amidinate), explored. The Royal Society of Chemistry 2005.
