Reactions of pentafluorophenylxenon(II) hexafluoroarsenate [C6F5Ze] [AsF6] with halide anions in acetonitrile

Reactions of [C₆F₅Xe]⁺ [AsF₆]⁻ in acetonitrile with halide anions X⁻ show different results depending on X. If X = I, Br or Cl, then C₆F₅X is obtained. If X = F, then C₆F₅H and C₆F₅---C₆F₅ are produced, and if X = HF₂, then C₆F₆, C₆F₅H and C₆F₅---C₆F₅ are formed.     

Über die Darstellung der N-Chlor-N-Methylammoniumsalze (CH3)nNCl4–n+MF6− (n = 1–3; M = As,Sb) und (CH3)2NCIX+MF6− (X = F,Br)

About the Preparation of N-Chloro-N-Methylammonium Salts (CH₃)_nNCl_4–n⁺MF₆^? (n = 1–3; M = As, Sb) and (CH₃)₂NClX⁺MF₆^? (X = F, Br) Simple one-step methods for the preparation of the methylated chloroammonium salts (CH₃)_nNCl_4–n⁺MF₆^? (n = 1–3; M = As, Sb) and for (CH₃)₂NClX⁺MF₆^? (X = F, Br) are reported. Their vibrational and NMR-spectroscopical data are discussed in comparison.     

Über die Gasphasenstruktur von CF3NCl2 und die Darstellung von CF3NCl2F+MF6− (M = As,Sb) und CF2 = NClF+SbF6−

Gas Phase Structure of CF₃NCl₂ and Preparation of CF₃NCl₂F⁺MF₆^? (M = As, Sb) and CF₂ = NCl₂F⁺SbF₆^? The gas phase structure of CF₃NCl₂ is reported. The following skeletal parameters are derived (r_a-values, error limits are 3σ values): N? C = 1.470(6) Å, N? Cl = 1.733(3) Å, ClNCl = 111.5(4)° and ClNC = 107.6(5)°. CF₃NCl₂F⁺MF₆^? is prepared by fluorination of CF₃NCl₂ with XeF⁺MF₆^?. The same educt CF₃NCl₂ reacts with XeF⁺SbF₆^? at ?40°C to CF₂ = NClF⁺SbF₆^? under elimination of ClF.     

Conductance of Selected Alkali Metal Salts in Aqueous Binary Mixtures of 2-Methoxyethanol at 25°C

Precise conductance measurements have been performed for lithium perchlorate, lithium tetrafluoroborate, lithium hexafluoroarsenate, sodium perchlorate, and sodium tetraphenylborate in 2-methoxyethanol–water mixtures at four different mole fractions, i.e., 0.056, 0.136, 0.262, and 0.486 of 2-methoxyethanol (69.73 D 26.55) at 25°C in the concentration range 0.0004–0.0642 mol-dm^–3. The limiting molar conductivity °, the association constant K _A, and the association distance R for the solvent mixtures have been evaluated from the conductance concentration data using the 1978 Fuoss conductance equation. The single-ion conductances have been estimated using the reference electrolyte tetrabutylam-monium tetraphynylborate(Bu₄NBPh₄). The analysis of the data indicates that for most salts ion association is appreciable in the solvent mixtures with a mole fraction of the cosolvent of 0.262 or higher. The results have been interpreted in terms of ion-solvent interactions and structural changes in the mixed solvent media.     

Solubility and solvate formation of lithium hexafluoroarsenate in acetonitrile

The solubility of LiAsF₆ in CH₃CN has been determined by the use of cooling curves. A partial phase diagram is presented which reveals a distinct dystectic corresponding to the formation of tetraacetonitrilolithium hexafluoroarsenate.     

Alkaline earth metal poly(hydrogen fluorides) hexafluoroarsenates(V) and hexafluorophosphate(V): M2(H2F3)(HF2)2(AF6) (M = Ca, A = As; M = Sr, A = As, P)

New compounds of the type M₂(H₂F₃)(HF₂)₂(AF₆) with M = Ca, A = As and M = Sr, A = As, P) were isolated. Ca₂(H₂F₃)(HF₂)₂(AsF₆) was prepared from Ca(AsF₆)₂ with repeated additions of neutral anhydrous hydrogen fluoride (aHF). It crystallizes in a space group P4₃22 with a = 714.67(10) pm, c = 1754.8(3) pm, V = 0.8963(2) nm³ and Z = 4. Sr₂(H₂F₃)(HF₂)₂(AsF₆) was prepared at room temperature by dissolving SrF₂ in aHF acidified with AsF₅ in mole ratio SrF₂:AsF₅ = 2:1. It crystallizes in a space group P4₃22 with a = 746.00(12) pm, c = 1805.1(5) pm, V = 1.0046(4) nm³ and Z = 4. Sr₂(H₂F₃)(HF₂)₂(PF₆) was prepared from Sr(XeF₂)_n(PF₆)₂ in neutral aHF. It crystallizes in a space group P4₁22 with a = 737.0(3) pm, c = 1793.7(14) pm, V = 0.9744(9) nm³ and Z = 4. The compounds M₂(H₂F₃)(HF₂)₂(AF₆) gradually lose HF at room temperature in a dynamic vacuum or during being powdered for recording IR spectra or X-ray powder ray diffraction patterns. All compounds are isotypical with coordination of nine fluorine atoms around a metal center forming a distorted Archimedian antiprism with one face capped. This is the first example of the compounds in which H₂F₃⁻ and HF₂⁻ anions simultaneously bridge metal centers forming close packed three-dimensional network of polymeric compounds with low solubility in aHF. The HF₂⁻ anions are asymmetric with usual F?F distances of 227.3-228.5 pm. Vibrational frequency (ν₁) of HF₂⁻ is close to that in NaHF₂. The anion H₂F₃⁻ exhibits unusually small F?F?F angle of 95.1°-97.6° most probably as a consequence of close packed structure.     

Reactions of (Nonafluorocyclohexen-1-yl)xenon(II) Hexafluoroarsenate with Halide Anions

The products of the reaction between the electrophilic alkenylxenonium cation [1-Xe⁺–C₆F₉] and the halide anions I^?, Br^?, Cl^? and F^? depend on the hardness of the halide anion. With the soft halides I^? and Br^? Xe(II) is formally displaced by halogen as well in basic MeCN as in superacidic (AHF¹), whereas with hard fluoride and chloride no reaction takes place in AHF. In MeCN F^? initiates the formation of alkenyl radicals, which abstract hydrogen from the solvent, whereas Cl^? exhibits borderline character: RH and RCl formation. Possible reaction paths are discussed. The reactivity of the arylxenonium cation [C₆F₅Xe]⁺ in AHF toward halide ions is reported and the relative electrophilicity of the cations [C₆F₅Xe]⁺ and [1-Xe⁺–C₆F₉] is determined by the competitive reaction with Cl^?. In addition the synthesis of cyclohexene 1-CF₃–C₆F₉ from C₆F₅CF₃ and XeF₂ is performed and its electrophilicity is compared with that of the aromatic compound C₆F₅CF₃.     

Reaction of NS with N3

Thionitrosyl hexafluoroarsenate, [NS][AsF₆], reacted with caesium azide, [Cs][N₃], to form S₂N₂ which polymerized to give (SN)_x. The structures of the following likely intermediate species were calculated at correlated MP2/6–31G(d,p) level of theory (relative energies in kcal mol⁻¹): thionitrosyl azide, N₃---N=S (37.8), thiazyl azide, N₃---SN (39.2) and cyclic N₄S (0.0).^‡     

Gemischtligandkomplexe des Rheniums. IX. Reaktionen am Nitridoliganden von [ReN(Me2PhP)(Et2dtc)2]. Synthese,Charakterisierung und Kristallstrukturen von [Re(NBCl3)(Me2PhP)(Et2dtc)2], [Re(NGaCl3)(Me2PhP)(Et2dtc)2] und [Re(NS)Cl(Me2PhP)2(Et2dtc)]

Mixed-ligand Complexes of Rhenium. IX. Reactions on the Nitrido Ligand of [ReN(Me₂PhP)(Et₂dtc)₂]. Synthesis, Characterization, and Structures of [Re(NBCl₃)(Me₂PhP)(Et₂dtc)₂], [Re(NGaCl₃)(Me₂PhP)(Et₂dtc)₂], and [Re(NS)Cl(Me₂PhP)₂(Et₂dtc)] BCl₃, GaCl₃ and S₂Cl₂ react with the well-known [ReN(Me₂PhP)(Et₂dtc)₂] by attack of the nucleophilic nitrido ligand. Final products of these reactions are [Re(NBCl₃)-(Me₂PhP)(Et₂dtc)₂], [Re(NGaCl₃)(Me₂PhP)(Et₂dtc)₂], and [Re(NS)Cl(Me₂PhP)₂Et₂dtc)] which have been studied by mass spectrometry, IR spectroscopy and X-ray diffraction. [Re(NBCl₃)(Me₂PhP)(Et₂dtc)₂] crystallizes in the triclinic space group P1 , Z = 2, a = 8.151(6), b = 9.935(8), c = 18.67(1) Å; α = 94.42(4), β = 97.09(1), γ = 101.35(4)°. The coordination geometry is a distorted octahedron. The equatorial coordination sphere is occupied by one phosphorus and three sulphur atoms. The fourth sulphur atom is in trans position to the Re?N? B moiety. The almost linear Re?N? B unit has an Re?N? B angle of 170.5(3)° with a Re? N bond length of 1.704(3) Å. The analogous [Re(NGaCl₃)(Me₂PhP)(Et₂dtc)₂] crystallizes in P2₁/c with a = 8.138(3), b = 18.279(2), c = 19.880(6) Å; β = 99.81(2)°; Z = 4. Rhenium has a distorted octahedral environment. The Re? N? Ga bond is slightly bent with an angle of 154.5(4)° and a Re? N bond length of 1.695(6) Å. [Re(NS)Cl(Me₂PhP)₂(Et₂dtc)] crystallizes in the triclinic space group P1 , Z = 4, a = 9.514(2); b = 16.266(5); c = 18.388(3) Å; α = 88.75(2), β = 76.59(2), γ = 85.50(2)° with two crystallographically independent molecules in the asymmetric unit. Rhenium has a distorted octahedral environment with the chloro ligand in trans position to the almost linear thionitrosyl group. The Re?N bond lengths are 1.795(6) and 1.72(1) Å, respectively, and the N?S distances are 1.55(1) and 1.59(1) Å, respectively.     

Über die Darstellung der Pnikogenoniumsalze AsH4+SbF6−, AsH4+AsF6−, SbH4+SbF6−

On the Preparation of Pnikogenonium Salts AsH₄⁺SbF₆^?, AsH₄⁺AsF₆^?, SbH₄⁺SbF₆^? The preparation of the pnikogenonium salts AsH₄⁺SbF₆^?, AsH₄⁺AsF₆^? and SbH₄⁺SbF₆^? by protonation from the hydrides AsH₃, SbH₃ in superacidic systems HF/SbF₅ and HF/AsF₅, resp. is reported. The salts are characterized by vibrational and mass spectra. A general valence force field is calculated. The following onium ions are know as hexafluoroantimonate: