Syntheses and vibrational spectra of xenon(VI) fluorogallate,xenon(VI) fluoroaluminate and xenon(VI) fluoroindate

Liquid xenon difluoride at 140°C does not react with aluminium, gallium, and indium trifluorides, neither does liquid xenon hexafluoride at 60°C. Therefore the reactions between the corresponding hydrazinium fluorometalates (N₂H₆AlF₅, N₂H₆GaF₅ and N₂H₅InF₄) and XeF₂ and XeF₆ were carried out. N₂H₆AlF₅, N₂H₆GaF₅ and N₂H₅InF₄ react with XeF₂ at 60°C (at 25°C in the case of indium) yielding only the corresponding trifluorides, while the reaction with XeF₆ proceeds at room temperature (at - 25°C in the case of indium) yielding XeF₆.2AlF₃, XeF₆.GaF₃ and xenon(VI) fluoroindate(III) contaminated with indium trifluoride. Spectroscopic evidence suggests that these compounds are salts of the XeF⁺₅ cation squashed between polymeric anions of the type (M₂F₇)^x-_x or (MF₄)^x-_x.     

Untersuchungen von Fluorometallaten (III), 11. Mitt.: Synthese und Kristallstruktur von Guanidinium Hexalfuoroaluminat, -gallat und -indat

The complexes [C(NH₂)₃]₃ MF₆,M=Al, Ga, In have been isolated from aqueous solutions of the corresponding fluorides. The compounds are isostructural and crystallize in the cubic space group Pa3 witha=13.933 (1) Å for [C(NH₂)₃]₃AlF₆,a=14.065 (1) Å for [C(NH₂)₃]₃GaF₆,a=14.340 (1) Å for [C(NH₂)₃]₃InF₆ andZ=8. TheMF ₆ ^3? anions are arranged as Na⁺ and Cl^? in the NaCl lattice. Guanidinium cations are distributed on 24-fold general positions.     

Synthese,Kristallstruktur und thermischer Abbau von Fluoroaluminaten der Zusammensetzung (NH4)[M(H2O)6][AlF6] (M = Zn,Ni), [Zn(H2O)6][AlF5(H2O)] und (PyH)4[Al2F10] · 4 H2O

Synthesis, Crystal Structure and Thermal Behaviour of Fluoroaluminates of the Composition (NH₄)[M(H₂O)₆](AlF₆) (M = Zn, Ni), [Zn(H₂O)₆][AlF₅(H₂O)], and (PyH)₄[Al₂F₁₀] · 4 H₂O Four new fluoroaluminates were obtained from fluoroacidic solutions of respective metal salts. The compounds of zinc ( I a : P2₁/c, a = 12.688(3), b = 6.554(1), c = 12.697(3) Å, β = 95.21(3)°, V = 1051.5(4) ų, Z = 4) and nickel ( I b : P2₁/c, a = 12.685(3), b = 6.517(1), c = 12.664(2)Å, β = 94.55(2)°, V = 1043.6(4) ų, Z = 4) are isotypic and represent a new structure type consisting of two different cations, NH₄⁺ and [M(H₂O)₆]²⁺ and [AlF₆]^3–‐anions. [Zn(H₂O)₆][AlF₅(H₂O)] ( II : C2/m, a = 10.769(2), b = 13.747(3), c = 6.487(1)Å, β = 100.02(3)°, V = 945.7(3) ų, Z = 4) is characterized by a H₂O/F‐disorder in the [AlF₅(H₂O)]‐octahedra in two trans positions. In (PyH)₄[Al₂F₁₀] · 4 H₂O ( III : Cmc2₁, a = 15.035(3), b = 20.098(4), c = 12.750(4) Å, V = 5364(2) ų, Z = 8), bioctahedral [Al₂F₁₀]^4– anions have been found for the first time. The structures are described and discussed in comparison. The new compounds were used as precursors in order to obtain new AlF₃‐phases. However, the thermal decomposition did not result in the formation of any new metastable AlF₃‐phase. Instead, phase mixtures of either α‐AlF₃ and β‐AlF₃ or AlF₃ and MF₂ were obtained.     

Thermisch induzierte Bewegungsvorgänge in kristallinen Guanidiniumhexafluorometallaten, (C(NH2)3)3MF6 (M = Al,Ga, In) — eine in situ ESR-Untersuchung

Thermally Induced Mobility in Crystalline Guanidinium Hexafluorometallates, (C(NH₂)₃)₃MF₆ (M = Al, Ga, In) — an in situ E.S.R. Study . The e.s.r. spectroscopic investigation of the title compounds was carried out most successfully by doping them with Cr^III ions. The metal ions in the centres of the MF₆ octahedra are substituted by the Cr^III ions. The zero field splitting parameter | D |, being a measure of the axial distortion of the CrF₆ octahedra, has been determined by fitting the calculated to the experimental resonant field values using a computer program. | D | decreases with increasing temperature. This process is completely reversible in the investigated temperature range of ? 190°C to 270°C. It is explained in terms of the thermally induced movability of the N? H … F network.     

Über die thermische Zersetzung der Hydraziniumpentafluorometallate N2H6MF5 des Eisens,Vanadiums und Aluminiums

On the Thermal Decomposition of Hydraziniumpentafluorometallates N₂H₆MF₅ of Iron, Vanadium and Aluminium The thermal decomposition of the hydraziniumpentafluorometallates of N₂H₆FeF₅, N₂H₆VF₅ and N₂H₆AlF₅ has been investigated by thermoanalytical, X-ray and i.r. spectroscopic methods. The thermal decomposition leads to ammonium compounds forming in consequence of disproportionation of the hydrazinium cation into ammonia and nitrogen. Under quasi-isobaric conditions a multistage decomposition mechanism has been detected. No hydrolysis reactions have been observed. In the iron system a partial reduction of Fe^III takes place. Consequently NH₄Fe₂F₆ is formed which decomposes via (NH₄)_1?xFeF_4?x (x = 0.6-0.8) with HTB-structure into FeF₃ and FeF₂. In the aluminium and vanadium system the formation of tetragonal (NH₄F)_y · MF₃-phases (y = 0.2-0.8) as intermediates has been observed. Final products of decomposition are VF₃ and α-AlF₃.     

Synthesis and Structure of (NH4)2[(AuI4)(MI4)] (M = Ga,In)

The compounds (NH₄)₂[(AuI₄)(MI₄)] (M = Ga, In) were obtained in sealed glass ampoules by reaction of I₂, NH₄I, Au and Ga or In as air‐sensitive black crystals. Both compounds crystallize in the orthorhombic space group Pnma (No. 62) and are isotypic: (NH₄)₂[(AuI₄)(GaI₄)], a = 12.619(2), b = 20.625(5) and c = 7.693(2) Å; (NH₄)₂[(AuI₄)(InI₄)], a = 12.587(2), b = 20.606(5) and c = 7.696(2) Å. The structures can be described as constituted of NH₄⁺ cations and anionic zig zag chains of alternating tetrahedral MI₄^– (M = In, Ga) and square planar AuI₄^– units running along [010]. Within the chains, the MI₄^– ions form weak interactions with two of their I atoms to the AuI₄^– ions resulting in strongly elongated AuI₆ octahedra.     

Ammonium-Alkali-Hexafluorometallate(lll) vom Elpasolith-Typ

Inhaltsübersicht. Durch Festkörperreaktion in Gold- oder Platinampullen unter Druck wurde die Darstellung von Ammonium-Alkali-Hexafluorometallaten(III) vom Typ (NH₄)₂AMF₆ (A = Li, Na, K, Rb) und A₂NH₄MF₆ (A = Eb, Cs) mit M = Al, Ga, Cr, Fe und V versucht. Die Verbindungen (NH₄)₂NaMF₆, (NH₄)₂KMF₆ und Cs₂NH₄MF₆ kristallisieren kubisch flächenzentriert im Elpasolith-Typ, wie aus Röntgenpulveraufnahmen, z. T. auch durch Intensitätsrechnung, belegt wird. Die Ammoniumionen liegen hier entweder in reiner 12facher (Na- und K-Verbindung) oder in reiner 6facher Koordination (Cs-Verbindung) vor. Ammonium Alkali Hexafluorometallates(III) of Elpasolite Type The preparation of ammonium alkali hexafluorometallates(III) of type (NH₄)₂AMF₆ (A = Li, Na, K, Rb) and A₂NH₄MF₆ (A = Rb, Cs), where M means Al, Ga, Cr, Fe and V, was attempted (by solid state reaction in sealed gold or platinum tubes under pressure. The compounds (NH₄)₂NaMF₆, (NH₄)₂KMF₆ and Cs₂NH₄MF₆ crystallize cubic face centered in the elpasolite structure as could be showed by X-ray powder patterns, in part by calculations of intensities. The ammonium ion have the coordination number 12 (Na and K compounds) or 6 respectively (Cs compounds).     

Zwei Galliumfluorid-Ammoniakate: Ga(NH3)F3 und Ga(NH3)2F3

Two Gallium Fluoride Ammine Complexes: Ga(NH₃)F₃ and Ga(NH₃)₂F₃ Two gallium trifluoride ammines, Ga(NH₃)F₃ and Ga(NH₃)₂F₃, are obtained as single crystals through oxidation of gallium metal with NH₄HF₂ (Ga : NH₄HF₂ = 1 : 1.5) and NH₄F (Ga : NH₄F = 1 : 3.5), respectively, at 450 °C and 400 °C. Ga(NH₃)F₃ crystallizes with the non-centrosymmetric space group Abm2 (a = b = 544.6(2) pm, c = 986.6(4) pm) forming two-dimensional layers of [Ga(NH₃)F₅] octahedra. The addition of another NH₃ molecule in Ga(NH₃)₂F₃ (orthorhombic, Immm, a = 700.0(3) pm, b = 724.7(2) pm, c = 393.1(1) pm) leads to one-dimensional rods of [Ga(NH₃)₂F₄] octahedra running parallel [001] which are stacked in the [010] direction. Infrared spectra suggest hydrogen bonding (N–H…F) in Ga(NH₃)F₃, for Ga(NH₃)₂F₃ an unequivocal statement is not possible.     

Darstellung und spektroskopische Charakterisierung der Difluoramino-fluoriminium-Hexafluorometallate F2NC(F)NX2+MF6– (X = H,D; M = As,Sb)

Preparation and Spectroscopic Characterization of the Difluoroaminofluoro-iminium-hexafluorometallates F₂NC(F)NX₂⁺MF₆^– (X = H, D; M = As, Sb) Difluorocyanamin, F₂NCN, does not react with the superacids XF/MF₅ (X = H, D; M = As, Sb) under formation of protonated nitrilium salts. At –78 °C iminium salts of the general form F₂NC(F)NX₂⁺MF₆^– are observed, which are characterized by vibrational and nmr spectroscopy. The structure and vibrational frequencies were computed ab initio at the Hartree-Fock (HF/6-31 + G*) and correlated Møller-Plesset (MP2/6-31 + G*) levels of theory.     

ChemInform Abstract: Quantum‐Chemical Calculations and IR Spectra of the (F2)MF2 Molecules (M: B,Al, Ga,In, Tl) in Solid Matrices: A New Class of Very High Electron Affinity Neutral Molecules.

The new class of neutral adduct molecules (F₂)MF₂ (M: B, Al, Ga, In, Tl) forms by reaction of laser‐ablated group 13 metal atoms with F₂ in excess Ar and Ne during condensation at 5 K.     

Synthesis and Characterization of the 1 : 1-Adducts of In(C6F5)3 with Acetonitrile,Glyme, and DMAP (DMAP = 4-(N,N-dimethylamino)pyridine), and [PNP][In(C6F5)4] (PNP = bis(triphenylphosphinanyliden)immonium) – the Crystal Structure of [PNP][In(C6F5)4]

In(C₆F₅)₃ · CH₃CN and In(C₆F₅)₃ · glyme were synthesized from InCl₃ and Cd(C₆F₅)₂ in CH₃CN or glyme in 43% and 35% yield, respectively. Replacement of CH₃CN or (C₂H₅)₂O by DMAP yielded the corresponding 1 : 1-adduct. [PNP][In(C₆F₅)₄] was best prepared from the corresponding cesium salt which was best synthesized from the reaction of stoichiometric amounts of In(C₆F₅)₃ · CH₃CN, (CH₃)₃ SiC₆F₅ and CsF in good yield. [PNP][In(C₆F₅)₄] crystallizes in the triclinic space group P 1, a = 1104.9(4) pm, b = 1442.4(6) pm, c = 1833.8(8) pm, α = 110.87(2)°, β = 92.04(3)°, γ = 96.55(3)°, Z = 2.     

Untersuchungen der Fluoro-metallate(III), 2. Mitt.: Thermoanalytische Untersuchungen von Hydrazinium-(1+ und2+)-fluoro-aluminaten-gallaten,und-indaten

Zusammenfassung Die thermische Zersetzung dieser Verbindungen im Argon wird beschrieben und führt zu den drei neuen Verbindungen N₂H₅GaF₄, N₂H₅InF₄ und N₂H₅GaF₄·N₂H₆F₂. Außerdem sind zwei neue Phasen mit den Verhältnissen N₂H₄2 Ga6 F und N₂H₄In3F isolierbar. Die thermische Zersetzung von N₂H₆AlF₅ verläuft analog dem N₂H₆GaF₅ ohne trennbare Stufen. Gitterabstände und IR-Spektren der neuisolierten Phasen sind angegeben.

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Fluoro metallates(III), II: Thermoanalytical investigation of hydrazinium(¹⁺ and²⁺)-fluoroaluminates,-gallates, and-indates

The thermal decomposition of these compounds in argon results in the following three new compounds: N₂H₅GaF₄, N₂H₅InF₄, and N₂H₅GaF₄·N₂H₆F₂. Besides, two new phases with composition N₂H₄2 Ga6 F and N₂H₄In3 F are noticed. The thermal decomposition of N₂H₆AlF₅ follows the same path as N₂H₆GaF₅, but no separable steps could be observed. IR spectra together with the d spacings of the new compounds are included.

     

Das Monoammoniakat des Galliumamidfluorids: Ga(NH3)(NH2)F2

The Monoammoniate of Gallium Amide Fluoride, Ga(NH₃)(NH₂)F₂ The oxidation of gallium metal with NH₄F leads at 325 °C in the presence of indium to single crystals of Ga(NH₂)F₂ · NH₃ [monoclinic, C2/m (no. 12), a = 1053.1(1), b = 557.4(1), c = 484.2(3) pm, β = 90.04(4)]. The crystal structure is built up from layers of corner-bridged [Ga(NH₃)₂F₄] and [Ga(NH₂)₂F₄] octahedra, respectively. The infrared spectrum proves the existence of the amide group in Ga(NH₂)F₂ · NH₃.     

Structures and Stability of Complexes of E(C6F5)3 (E = B,Al, Ga,In) with Acetonitrile

Complexes formed by interaction of E(C₆F₅)₃ (E = B, Al, Ga, In) with excess of acetonitrile (AN) were structurally characterized. Quantum chemical computations indicate that for Al(C₆F₅)₃ and In(C₆F₅)₃ the formation of a complex of 1:2 composition is more advantageous than for B(C₆F₅)₃ and Ga(C₆F₅)₃, in line with experimental observations. Formation of the solvate [Al(C₆F₅)₃ · 2AN] · AN is in agreement with predicted thermodynamic instability of [Al(C₆F₅)₃ · 3AN]. Tensimetry study of B(C₆F₅)₃ · CH₃CN reveals its stability in the solid state up to 197 °C. With the temperature increase, the complex undergoes irreversible thermal decomposition with pentafluorobenzene formation.     

From Isolated Polyanions to 1‐D Structure: Synthesis and Crystal Structure of Hybrid Fluorides {[(C2H4NH3)3NH]4+}2 · (H3O)+ · [Al7F30]9– and {[(C2H4NH3)3NH]4+}2 · [Al7F29]8– · (H2O)2

Two new hybrid fluorides, {[(C₂H₄NH₃)₃NH]⁴⁺}₂ · (H₃O)⁺ · [Al₇F₃₀]^9– ( I ) and {[(C₂H₄NH₃)₃NH]⁴⁺}₂ · [Al₇F₂₉]^8– · (H₂O)₂ ( II ), are synthesized by solvothermal method. The structure determinations are performed by single crystal technique. The symmetry of both crystals is triclinic, sp. gr. P 1, I : a = 9.1111(6) Å, b = 10.2652(8) Å, c = 11.3302(8) Å, α = 110.746(7)°, β = 102.02(1)°, γ = 103.035(4)°, V = 915.9(3) ų, Z = 1, R = 0.0489, R_w = 0.0654 for 2659 reflections, II : a = 8.438(2) Å, b = 10.125(2) Å, c = 10.853(4) Å, α = 106.56(2)°, β = 96.48(4)°, γ = 94.02(2)°, V = 877.9(9) ų, Z = 1, R = 0.0327, R_w = 0.0411 for 3185 reflections. In I , seven corner‐sharing AlF₆ octahedra form a [Al₇F₃₀]^9– anion with pseudo 3 symmetry; such units are found in the pyrochlore structure. The aluminum atoms lie at the corners of two tetrahedra, linked by a common vertex. In II , similar heptamers are linked in order to build infinite (Al₇F₂₉)_n^8– chains oriented along a axis. In both compounds, organic moieties are tetra protonated and establish a system of hydrogen bonds N–H…F with four Al₇F₃₀^9– heptamers in I and with three inorganic chains in II .     

Hydrothermal synthesis and crystal structure of a new ammonium gallium hydroxyphosphate (NH4)Ga(OH)PO4

A new ammonium gallium hydroxyphosphate (NH₄)Ga(OH)PO₄ was synthesized under mild hydrothermal conditions (200°C, τ = 168 h). The equimolar content of Ga and P was determined by chemical analysis and electron probe X-ray microanalysis. The presence of NH₄ and OH groups was demonstrated by IR and Raman spectroscopy. An ab initio model of the crystal structure was refined by the Rietveld method (space group P2₁/m, Z = 2): a = 4.4832(1) Å, b = 6.0430(1) Å, c = 8.5674(1) Å, β = 98.019(1)°, R _p = 0.0552, R _wp = 0.0723. A zero SHG signal (T = 300 K) confirmed a centrosymmetric structure of the compound. The structure contains layers composed of GaO₄(OH)₂ octahedra and PO₄ tetrahedra. The interlayer space accommodates ammonium cations. The layer is based on linear chains of edge-sharing GaO₄(OH)₂ octahedra with a zigzag trans-arranged-Ga-(OH)-Ga-(OH)-backbone. The construction of the layer in (NH₄)Ga(OH)PO₄ was found to be topologically related to that in (En)_0.5Fe(OH)PO₄. The effect of the gradual F^? → OH^? substitution in the quasi-morphotropic series (NH₄)GaF_1-δ(OH)_δPO₄ (δ = 0, 0.5, 1.0) on the degree of polarization of the mixed anionic radical was considered. (NH₄)Ga(OH)PO₄ is thermally unstable: removal of NH₃ and H₂O molecules in the range 170–450°C is accompanied by the formation of two polymorphs of GaPO₄.     

The transformation of Sn(ND3)2F4 into Sn(ND2)2F2. Synthesis and neutron crystal structure determination of Sn(ND2)2F2

Diamido-difluoro-tin Sn(ND₂)₂F₂ can be produced by ammonolysis from (NH₄)₂SnF₆ at 633 K. The compound is a product formed from Sn(ND₃)₂F₄ during the ammonolysis reaction. Sn(ND₂)₂F₂ isostructural with Sn(NH₂)₂F₂ crystallizes in space group C2/m with lattice constants a = 1072.92(7), b = 325.97(1) pm, c = 505.79(4) pm and β = 105.713(6) ° (V = 170.28(1) ·10⁶ pm³) containing two formula units per unit cell. Data refinement by the Rietveld method of neutron time-of-flight data collected at POLARIS yields a weighted profile R-value R_wp = 0.022. Tin is octahedrally coordinated by two fluorine atoms and four amido groups. The octahedra are connected to one-dimensional chains by edge sharing. The ND₂ groups are in the bridging position whilst the fluorine atoms are terminal. Nearly linear (175.2(4) °) and angular (134.35(8) °) N-D···F hydrogen linkages connect the chains.     

Darstellung und Struktur von Sn(NH2)2F2

Synthesis and Structure of Sn(NH₂)₂F₂ Diamido-difluoro-tin Sn(NH₂)₂F₂ can be produced by ammonolysis from (NH₄)₂SnF₆ at 613 K. The compound is a product from Sn(NH₃)₂F₄ formed during the ammonolysis reaction. Sn(NH₂)₂F₂ crystallizes in space group C2/m (No. 12) with lattice constants a = 1070.18(7), b = 325.38(3) pm, c = 505.02(3) pm and β = 105.728(3)° (V = 169.271(6) · 10⁶ pm³) containing two formula units per unit cell. Data refinement by the Rietveld method yields a Bragg R-value of R_Bragg = 0.0514 (Profile R-value R_wp = 0.177). Tin is octahedrally coordinated by two fluorine atoms and for amido groups. The octahedra are connected to one-dimensional strings by edge sharing. The NH₂ groups are in the bridging position whilst the fluorine atoms are terminal.     

Dielectric and thermocurrent studies of some fluoride and oxide fluoride compounds with a (NH4)3FeF6−related structure

Dielectric and thermocurrent measurements have been carried out on (NH₄)₃AlF₆,(NH₄)₃FeF₆ and Rb₃FeF₆ ceramic samples. A maximum of permittivity is observed close to the transition temperature (T_tr(NH₄)₃AlF₆ = 217 K; T_tr(NH₄)₃FeF₆ = 264 K; T_tr(Rb₃FeF₆) = 629 K). This non cubic-cubic transition is of the ferroelastic type. The high Curie temperature of the rubidium iron fluoride causes large dielectric losses at the transition and thermocurrent measurements cannot be performed. On the contrary, in the low-temperature phase of the ammonium compounds a polarization current of about 10-9A/cm² is obtained and can be reversed when the sign of the polarization field is changed. This property could correspond to a ferroelectric behavior. However no pyroelectric current is detected when the temperature decreases from T_tr. Another hypothesis, based on the field-induced polarization, has been also considered.In connection with the ferroelectric properties of Rb₃MoO₃F₃, the system Rb₃MoO₃F₃Rb₃FeF₆ has been performed. Extended domains of solid solution with Rb₃(Mo_1?xFe_x)O_3?3xF_3+3x formula and having a (NH₄)₃FeF₆-related structure have been pointed out. The replacement of oxygen by fluorine leads to a strong decrease of the ferroelectric Curie temperature: T_C(x=0) = 538 K, T_C(x=0.4) < 80 K. This result is in good agreement with the lack of ferroelectricity in A₃MF₆ fluorides. In any case, the low-temperature phase is ferroelastic and is characterized by a remanent polarization.