Thermal reaction between XeF2 and excess TiF4 resulted in the unexpected formation of a highly ionized XeII species. The products Xe2F3Ti8F33 and XeF2Ti9F38 represent the first examples of Xe2F3+ and ...XeF+ compounds, which differ from known XeII salts containing discrete fluoride anions with pentavalent metalloid/metal centers. A new structural type of 2D polyanion Ti8F33− and the formation and structure of the novel 1D Ti9F382− are discussed. Both products were characterized by single‐crystal X‐ray analysis and Raman spectroscopy.
Stronger together: The molecule TiF4 is unable to efficiently remove fluoride from XeF2. However, at elevated temperatures, the large polytitanate species formed have an enhanced fluoride affinity, comparable to that of the strongest Lewis acids. Thermal reaction between XeF2 and TiF4 afforded colorless crystals the XeII species Xe2F3Ti8F33 (see picture) and XeF2Ti9F38 which were isolated and structurally characterized.
The reactions between compounds of the type MAF6 (M = alkali metal; A = P, As, V, Ru, Ir, Sb, Nb, Ta) and xenon difluoride were studied in anhydrous hydrogen fluoride solvent. The coordination ...products M(XeF2) n AsF6 were only observed in the case of LiAF6 (A = P, As, Ru, Ir), and the crystal structure of Li(XeF2)3AsF6 was determined (monoclinic space group P21 with a = 6.901(9) Å, b = 13.19(2) Å, c = 6.91(1) Å, β = 91.84(2)°, and Z = 2). The coordination sphere of lithium is comprised of six F atoms. The compound series was also characterized by Raman spectroscopy.
In the system BaF
2/PF
5/XeF
2/anhydrous hydrogen fluoride a new coordination compound, Ba(XeF
2)
4(PF
6)
2, was isolated. The XeF
2 molecules are interacting as ligands directly with the Ba
2+ ...cations. The compound crystallizes in the triclinic space group
P
1
¯
with
a
=
8.739(2)
Å,
b
=
8.912(2)
Å,
c
=
25.855(7)
Å,
α
=
76.331(6),
β
=
83.085(6),
γ
=
81.212(6),
V
=
1926.2(8)
Å
3 at 200
K and
Z
=
4. The structure consists of two crystallographically independent barium atoms with the coordination numbers 10 and 12. The barium atoms and the bridging XeF
2 molecules form double layers which are further interconnected into the 3-D network by the weak Xe⋯F (PF
6
−) interactions. The Raman spectrum of Ba(XeF
2)
4(PF
6)
2 clearly shows the presence of bridging XeF
2 molecules.
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The purpose of this study was to develop an analytical procedure for determination of the amount of total fluoride in total diet samples, including drinking water and beverages. Samples were taken by ...the duplicate portion technique and decomposed by alkali carbonate fusion using KNaCO
3, and the amount of fluoride in solution was determined by fluoride ion selective electrode using the multiple known addition technique. The mean amount of total fluoride determined in 20 total diet samples obtained from the Slovenian Military was 1.84
±
0.70
mg/kg on a dry matter basis. Accordingly the estimated daily intake was 1.50
±
0.56
mg.
Coordination of KrF2 to a Naked Metal Cation, Mg2 Lozinšek, Matic; Mercier, Hélène P. A.; Brock, David S. ...
Angewandte Chemie International Edition,
May 22, 2017, Letnik:
56, Številka:
22
Journal Article
Recenzirano
Examples of coordination compounds in which KrF2 functions as a ligand are very rare. In contrast, XeF2 provides a rich coordination chemistry with a variety of main‐group and transition metal ...cations. The reactions of Mg(AsF6)2 and KrF2 in HF or BrF5 solvent have afforded Mg(KrF2)4(AsF6)2 and Mg(KrF2)4(AsF6)2⋅2 BrF5, respectively, the first examples of a metal cation ligated by KrF2. Their X‐ray crystal structures and Raman spectra show that the KrF2 ligands and AsF6− anions are F‐coordinated to a naked Mg2+ cation. Quantum‐chemical calculations are consistent with essentially non‐covalent ligand‐metal bonding. These compounds significantly extend the XeF2–KrF2 analogy and the limited chemistry of krypton by introducing a new class of coordination compound in which KrF2 functions as a ligand towards a naked metal cation.
Krypton difluoride, a thermodynamically unstable and potent oxidative fluorinator, coordinates to Mg2+ to form the coordination complexes, Mg(KrF2)4(AsF6)2 and Mg(KrF2)4(AsF6)2⋅2 BrF5. The complexes were characterized by low‐temperature single‐crystal X‐ray diffraction and low‐temperature Raman spectroscopy. Computational studies show that the Mg−F bonds are essentially non‐covalent, weakly electrostatic interactions.
XeF₄ as a Ligand for a Metal Ion Tavcar, Gasper; Zemva, Boris
Angewandte Chemie (International ed.),
01/2009, Letnik:
48, Številka:
8
Journal Article
Recenzirano
Noble molecule: Mg(XeF₂)(XeF₄)(AsF₆)₂ is the first coordination compound in which XeF₄ acts as a ligand to a metal center. It is also the first known compound, in which XeF₂ and XeF₄ are ...simultaneously coordinated to the same metal center (see structure; purple Xe, green F, gray Mg, yellow As).
Fluoroacid-base reactions of a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium fluorohydrogenate (EMIm(HF)2.3F, EMIm = 1-ethyl-3-methylimidazolium cation), and Lewis fluoroacids (BF3, PF5, ...AsF5, NbF5, TaF5 and WF6) give EMIm salts of the corresponding fluorocomplex anions, EMImBF4, EMImPF6, EMImAsF6, EMImNbF6, EMImTaF6 and EMImWF7, respectively. Attempts to prepare EMImVF6 by both the acid-base reaction of EMIm(HF)2.3F with VF5 and the metathesis of EMImCl with KVF6 failed due to the strong oxidizing power of the pentavalent vanadium, whereas EMImSbF6 was successfully prepared only by the metathesis of EMImCl and KSbF6. EMImBF4, EMImSbF6, EMImNbF6, EMImTaF6 and EMImWF7 are liquids at room temperature whereas EMImPF6 and EMImAsF6 melts at around 330 K. Raman spectra of the obtained salts showed the existence of the EMIm cation and corresponding fluorocomplex anions. IR spectroscopy revealed that strong hydrogen bonds are not observed in these salts. EMImAsF6(mp 326 K) and EMImSbF6(mp 283 K) are isostructural with the previously reported EMImPF6. The melting point of the hexafluorocomplex EMIm salt decreases with the increase of the size of the anion (PF6- < AsF6- < SbF6- <NbF6- approximately TaF6-).
Effect of conductive additives and surface modification with NF
3 and ClF
3 on the charge/discharge behavior of Li
4/3Ti
5/3O
4 (≈4.6
μm) was investigated using vapor grown carbon fiber (VGCF) and ...acetylene black (AB). VGCF and mixtures of VGCF and AB increased charge capacities of original Li
4/3Ti
5/3O
4 and those fluorinated with NF
3 by improving the electric contact between Li
4/3Ti
5/3O
4 particles and nickel current collector. Surface fluorination increased meso-pore with diameter of 2
nm and surface area of Li
4/3Ti
5/3O
4, which led to the increase in first charge capacities of Li
4/3Ti
5/3O
4 samples fluorinated by NF
3 at high current densities of 300 and 600
mA
g
−1. The result shows that NF
3 is the better fluorinating agent for Li
4/3Ti
5/3O
4 than ClF
3.
Silver(I) tetrafluoridooxidovanadate(V) which contains the polymeric chain anion, VOF(4)(nn-), has been prepared in reaction between AgNO(3) and VOF(3) in anhydrous HF solvent and characterised in ...the solid state by single-crystal X-ray diffraction and Raman spectroscopy. Pale yellow crystals of AgVOF(4) crystallise in a monoclinic P2(1)/c space group with a = 5.5452(4) Å, b = 5.0071(3) Å, c = 13.6511(11) Å, beta = 100.543(3)°, and V = 372.63(5) Å(3) at 200 K with Z = 4. The most intense feature in the Raman spectrum is the V=O stretching band of the anion at 1008 cm-1. Solid-state conformational isomerism exists between VOF(4)(-) anions in crystal structures of AgVOF(4) and previously reported and structurally characterised KVOF(4) and CsVOF(4) salts.
 (A = P, ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0020-1669/small "[Li(XeF2) n ](AF6) (A = P, As, Ru, Ir), the First Xenon(II) Compounds of Lithium. Synthesis, Raman Spectrum, and Crystal Structure of [Li(XeF2)3](AsF6)")
