Bridging Fluorine Research Articles

The Crucial Role of Sb2F10 in the Chemical Synthesis of F2.

The purely chemical synthesis of fluorine is a spectacular reaction which for more than a century had been believed to be impossible. In 1986, it was finally experimentally achieved, but since then this important reaction has not been further studied and its detailed mechanism had been a mystery. The known thermal stability of MnF4 casts serious doubts on the originally proposed hypothesis that MnF4 is thermodynamically unstable and decomposes spontaneously to a lower manganese fluoride and F2. This apparent discrepancy has now been resolved experimentally and by electronic structure calculations. It is shown that the reductive elimination of F2 requires a large excess of SbF5 and occurs in the last reaction step when in the intermediate [SbF6][MnF2][Sb2F11] the addition of one more SbF5 molecule to the [SbF6]- anion generates a second tridentate [Sb2F11]- anion. The two tridentate [Sb2F11]- anions then provide six fluorine bridges to the Mn(II) cation thereby facilitating the reductive elimination of the two fluorine ligands as F2.

Die entscheidende Rolle von Sb2F10 bei der chemischen Synthese von F2

AbstractDie Synthese von elementarem Fluor auf rein chemischem Weg ist spektakulär und galt länger als ein Jahrhundert als unmöglich. Im Jahr 1986 war man schließlich erfolgreich. Seitdem wurde diese wichtige Reaktion nicht weiter untersucht und ihr detaillierter Mechanismus blieb ein Rätsel. Die ursprüngliche Hypothese eines thermodynamisch instabilen MnF4, welches sich spontan zu einem Manganfluorid niedrigerer Oxidationsstufe und elementarem Fluor zersetzt, wird durch die bekannte thermische Stabilität von MnF4 in Frage gestellt. Diese scheinbare Diskrepanz konnte nun experimentell und durch quantenchemische Rechnungen aufgeklärt werden. Die reduktive Eliminierung von F2 aus MnF4 erfordert einen großen Überschuss an SbF5. Sie findet im letzten Reaktionsschritt statt, wenn sich an das Zwischenprodukt [SbF6][MnF2][Sb2F11] ein weiteres SbF5‐Molekül unter Bildung eines weiteren tridentaten [Sb2F11]−‐Anions anlagert. Die beiden [Sb2F11]−‐Anionen stellen dem Mn‐Atom so sechs verbrückende F‐Atome zur Verfügung und ermöglichen damit die reduktive Eliminierung der beiden terminalen Fluoridoliganden als F2.

Estimation of the proportions of aluminum-fluorine species in NaF-AlF3 mixtures by in situ Raman spectroscopy and theoretical simulations

The quantitative distribution of different types of clusters in a binary NaF-AlF3 molten salt system with a series of cryolite ratios (CR, NaF/AlF3 molar ratio) was explored by in situ high-temperature Raman spectroscopy in conjunction with quantum chemistry (QC) ab initio calculations. Density functional theory (DFT) was used to simulate the Raman spectra of solid crystalline Na5Al3F14 (CR = 1.67) and Na3AlF6 (CR = 3.00). Aluminum-fluorine molecular model clusters containing species with typical characteristic microstructures were built in a molten NaF-AlF3 system. Deconvolution of the major stretching vibrational bands of Al-F-Al and Al-F bonds was carried out by using the Voigt function. The anionic fractions of different species present in the molten NaF-AlF3 system were quantitatively analyzed by a function of the microstructure dependent on Raman scattering cross sections (RSCS). AlF63-, AlF52-, and AlF4- were the dominant species in the aluminum-fluorine molten salt system. As the NaF in the melt increased, the content of AlF52- reached the maximum concentration when CR = 2.00. Apart from the recognized existence of both AlF4- and AlF63-, the aluminum bridging fluorine species of Al2F7- has been proven to exist in molten systems when CR ≤ 1.00. The relationship between the viscosity and various (n-3)Na+·AlFn(n-3)- species distributions has been investigated. The results showed that the contribution of different (n-3)Na+·AlFn(n-3)- to viscosity was essentially the same, and simply depended on the number of different species.

Ab initio molecular dynamics study on microstructure and diffusion properties of CaF2-2.2NaF-AlF3 system

• [AlF 5 ] 2− , [AlF 4 ] − , [AlF 6 ] 3− and [Al 2 F x ] (x−6)− always coexist in molten salt system. • The action intensity of Ca 2+ on [AlF x ] (x−3)− is [AlF 4 ] − < [AlF 6 ] 3− < [AlF 5 ] 2− . • The self-diffusion property of Al 3+ is [AlF 5 ] 2− > [AlF 6 ] 3− > [AlF 4 ] − . The lack of micro-mechanism research on the influence of Ca 2+ in cryolite molten salt has brought great difficulties to the improvement of current efficiency in actual production. The microstructure and diffusion characteristics of molten salt were studied by using ab initio molecular dynamics method, combined with the bridge fluorine distribution and diffusion coefficient of different complex ions. It is found that [AlF 5 ] 2− , [AlF 6 ] 3− , [AlF 4 ] − , [Al 2 F 9 ] 3− and [Al 2 F 10 ] 4− coexist in molten salt system. With the increase of Ca 2+ , [AlF 5 ] 2− is more easily attracted by Ca 2+ but has better self-diffusion performance, and [AlF 6 ] 3− is more easily crosslinked with other [AlF x ] (x−3)− .

Molecular Dynamics Simulation Study of the Effect of Ni, Fe, Cu on Cryolite Molten Salt System 78% Na&lt;sub&gt;3&lt;/sub&gt;AlF&lt;sub&gt;6&lt;/sub&gt;-9.5%AlF&lt;sub&gt;3&lt;/sub&gt;-5.0%CaF&lt;sub&gt;2&lt;/sub&gt;-7.5%-Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;

The effect of different additives Ni, Fe, Cu on the structure and properties of electrolyte system 78% Na3AlF6- -9.5%AlF3-5.0%CaF2-7.5%Al2O3 at 1200K and 1.01Mpa was studied by molecular dynamics method. The radial distribution function, coordination number, diffusion coefficient, conductivity, and viscosity of the system were discussed in detail. The results demonstrated that the order of the self-diffusion coefficient of ions in the electrolyte system is: Na+ &gt; F- &gt; O2- &gt; Ca2+ &gt;Al3+. The addition of Ni and Fe connected the free aluminum composite ion groups in the system through fluorine bridges, which enhanced the interaction between Al3+ and Al3+. The addition of Cu weakened the interaction between Al3 + and Al3+ and the F-. The interaction between Al3+ and Na+, [AlF7]4- ionic groups might appeared in the melt system. After adding NiO, Fe2O3, and Cu, the electrical conductivity of the system increased, and the viscosity decreased. The research work revealed the influence of Ni, Fe, Cu on the ion existence form, mobility, inter-ion interaction and diffusion mechanism of cryolite molten salt system, which has important guiding significance for aluminum electrolysis production.

Theoretical insights into the dimerization mechanism of aluminum species at two different pH conditions

Dimerization mechanism of aluminum species is investigated in weakly acidic solutions and in strongly alkaline solutions using density functional theory, respectively. The results indicate the dimerization is controlled by dehydration of monomeric aluminum and the dissolution of dimer is controlled by the hydroxyl bridge cleavage in weakly acidic solutions. The two processes are enhanced by the rising pH. In addition, the main pathway generating the fluorine bridge is not the direct polymerization, but the terminal substitution of F− into polymeric aluminum followed by the transition of terminal F to bridging F. The formation of fluorine bridge promotes dissolution and di-fluorine-bridged dimer should be excluded. In strongly alkaline solutions, the formation processes of three dimers were speculated, and the existence of mono-hydroxyl-bridged dimer is denied due to the extraordinary instability and high formation energy barriers. It is possible that mono-oxygen-bridged and di-hydroxyl-bridged dimers coexist in highly alkaline solutions. However, the salts of mono-oxygen-bridged anion are much more stable than salts of di-hydroxyl-bridged anion due to the effect of counter cations and the removal of ambient water molecules.

KF-NaF-AlF&lt;sub&gt;3&lt;/sub&gt;体系结构性质的分子动力学模拟

近年来低温铝电解质的研究已成为铝电解工业上节能减排的热点问题，对其基本物理化学性质的探索是一个必然的过程。本文运用密度泛函理论与经典分子动力学方法相结合的方法系统研究了1100 K下xKF-2.2NaF-AlF3熔盐体系的结构性质和输运性质。研究结果表明在平衡的高温钾冰晶石熔盐体系中六配位[AlF6]3−、五配位[AlF5]2−、四配位[AlF4]−络合离子共同存在，且六配位铝氟离子集团占主导地位(70%以上)，并会发生部分的离解，生成五配位或者四配位离子团；当KF浓度增大时，电解质体系中游氟原子含量会增加，桥氟含量逐渐降低，体系的聚合程度也会随之下降。此外，KF的加入使得桥氟离子解离，Na、Al的自扩散系数会先增大后降低，体系显示出低粘度高电导率的特性，但当KF浓度达到2%后，电导率会逐渐降低。 The study of low temperature aluminium electrolytes has become a hot issue for energy saving and emission reduction in the aluminium electrolysis industry in recent years, and the exploration of their basic physicochemical properties is an inevitable process. In this paper, the structural and transport properties of the nKF-2.2NaF-AlF3 molten salt system at 1100 K have been systematically investigated using a combination of density flooding theory and classical molecular dynamics methods. The results show that in the equilibrium high-temperature potassium cryolite molten salt system, hexacoordinated [AlF6]3-, pentacoordinated [AlF5]2- and tetracoordinated [AlF4]- complex ions co-exist, and the hexacoordinated aluminium-fluorine ion group dominates (more than 70%) and undergoes partial dissociation to produce pentacoordinated or tetracoordinated ion groups; As the KF concentration increases, the amount of free fluorine atoms in the electrolyte system increases, the bridge fluorine content gradually decreases and the degree of polymerisation of the system decreases. In addition, the addition of KF causes the dissociation of the bridging fluorine ions, the self-diffusion coefficients of Na and Al will first increase and then decrease, and the system shows the characteristics of low viscosity and high conductivity, but when the KF concentration reaches 2%, the conductivity will gradually decrease.

Reactions of Molybdenum and Tungsten Oxide Tetrafluoride with Sulfur(IV) Lewis Bases: Structure and Bonding in [WOF4]4, MOF4(OSO), and [SF3][M2O2F9] (M = Mo, W).

The structure of [WOF4]4 has been reinvestigated by low-temperature X-ray crystallography and DFT (MN15/def2-SVPD) studies. Whereas the W4F4 ring of the tetramer is planar and disordered in the solid state, the optimized gas-phase geometry prefers a disphenoidally puckered W4F4 ring and demonstrates asymmetric fluorine bridging. Dissolution of MOF4 (M = Mo, W) in SO2 and SF4 results in the formation of MOF4(OSO) and [SF3][M2O2F9], respectively. Both SO2 adducts and [SF3][Mo2O2F9] have been characterized by X-ray crystallography. The crystal structure of [SF3][Mo2O2F9] reveals dimerization of the ion pair that results in a rare heptacoordinate sulfur center. Optimization of the {[SF3][M2O2F9]}2 dimers in the gas phase, however, results in the elongation of one contact such that the sulfur centers are effectively hexacoordinate. Meanwhile, the crystal structure of [SF3][W2O2F9]·HF instead demonstrates hexacoordinate sulfur centers and a highly unusual coordination to [SF3]+ from [W2O2F9]- through an oxido ligand. While [SF3][W2O2F9] does not decompose at ambient temperature, MOF4(OSO) and [SF3][Mo2O2F9] are unstable toward evolution of SO2 or SF4. Computational studies reveal that the monomerization of [WOF4]4 in the gas phase at 25 °C is thermodynamically unfavorable using SO2, but favorable using SF4, consistent with the relative thermal stabilities of WOF4(OSO) and [SF3][W2O2F9].

Difluorochloronium(III) Fluoridometallates – from Molecular Building Blocks to (Helical) Chains

Difluorochloronium(III) compounds were synthesized from the reaction of metal powders (Ru, Os, Ir, Au), metal fluorides (NbF5, SbF3, BiF5) or a metal chloride (TaCl5) with excess liquid chlorine trifluoride. The compounds ClF2[AuF4], ClF2[MF6] (M = Nb, Ta, Ru, Os, Ir, Sb, Bi) and ClF2[Ta2F11] were obtained in crystalline form and their crystal structures were determined by single‐crystal X‐ray diffraction. The ClF2+ cations in the investigated compounds are bent, containing two strong, short, mainly covalent Cl–F bonds and two sterically active, free valence electron pairs in a pseudo‐tetrahedral arrangement. The coordination around the Cl atom is extended by two highly ionic, long fluorine bridges to neighboring fluoridometallate anions, resulting in a total coordination number of six. The crystal structures vary among the ClF2+ compounds and range from molecular building blocks, such as dimeric (ClF2[AuF4])2 and (ClF2[Ta2F11])2, to chains, some of which being helical, as in ClF2[MF6], (M = Nb, Ta, Ru, Os, Ir, Sb, Bi). Quantum‐chemical solid‐state and gas‐phase calculations were carried out to elucidate the bonding within the ClF2+ cations and their interactions with the bridging F atoms.

Effect of Aluminium Fluoride on the Structure and Properties of Cryolite Alumina Molten Salt System

The influence of aluminium fluoride AlF3 on the structure and properties of cryolite-Al2O3 melts are studied by molecular dynamics simulations at 1283 K and 0.1 MPa. The structure property such as radial distribution functions and coordination numbers, and the physical-chemical property such as density, conductivities, diffusion coefficients, and viscosities of the systems are obtained. It is shown that with the increase of aluminium fluoride content, fluorine ions in (Na3AlF6+4%Al2O3)1-w (AlF3) w molten salt system will replace the position of oxygen in alumina to form aluminium oxy-fluoride ion group, while aluminium ion group will form larger aluminium composite ion group through the connection of oxygen bridge and fluorine bridge. The formation of these ionic groups results in the decrease of the diffusion coefficient of anion and anion, the increase of viscosity and the decrease of conductivity in (Na3AlF6+4%Al2O3)1-w (AlF3) w , molten salt system.

Syntheses, Structures, and Bonding of NgF2 ⋅CrOF4 , NgF2 ⋅2CrOF4 (Ng=Kr, Xe), and (CrOF4 )∞.

The noble-gas difluoride adducts, NgF2 ⋅CrOF4 and NgF2 ⋅2CrOF4 (Ng=Kr and Xe), have been synthesized and structurally characterized at low temperatures by Raman spectroscopy and single-crystal X-ray diffraction. The low fluoride ion affinity of CrOF4 renders it incapable of inducing fluoride ion transfer from NgF2 (Ng=Kr and Xe) to form ion-paired salts of the [NgF]+ cations having either the [CrOF5 ]- or [Cr2 O2 F9 ]- anions. The crystal structures show the NgF2 ⋅CrOF4 adducts are comprised of Ft -Ng-Fb - - -Cr(O)F4 structural units in which NgF2 is weakly coordinated to CrOF4 by means of a fluorine bridge, Fb , in which Ng-Fb is elongated relative to the terminal Ng-Ft bond. In contrast with XeF2 ⋅2MOF4 (M=Mo or W) and KrF2 ⋅2MoOF4 , in which the Lewis acidic, F4 (O)M- - -Fb - - -M(O)F3 moiety coordinates to Ng through a single M- - -Fb -Ng bridge, both fluorine ligands of NgF2 coordinate to CrOF4 molecules to form F4 (O)Cr- - -Fb -Ng-Fb - - -Cr(O)F4 adducts in which both Ng-Fb bonds are only marginally elongated relative to the Ng-F bonds of free NgF2 . Quantum-chemical calculations show that the Cr-Fb bonds of NgF2 ⋅CrOF4 and NgF2 ⋅2CrOF4 are predominantly electrostatic with a small degree of covalent character that accounts for their nonlinear Cr- - -Fb -Ng bridge angles and staggered O-Cr- - -Fb -Ng-Ft dihedral angles. The crystal structures and Raman spectra of two CrOF4 polymorphs have also been obtained. Both are comprised of fluorine-bridged chains that are cis- and trans-fluorine-bridged with respect to oxygen.

Effect of CaF2 on the Viscosity and Microstructure of CaO–SiO2–Al2O3 Based Continuous Casting Mold Flux

In this study, a CaO–SiO2–Al2O3-based continuous casting mold flux was designed using the FactSage thermodynamics software to determine the composition range of CaF2. The viscosity characteristics of the mold flux were determined using a rotating viscometer. The results show that the constant temperature viscosity at 1300 °C decreases gradually as CaF2 content is increased from 3% to 11% in the CaO–SiO2–Al2O3-based slag. Viscosity is reduced from 0.854 to 0.241 Pa·s, viscous the flow activation energy is reduced from 157.74 to 114.34 kJ·mol−1, and the break temperature is reduced from 1280 to 1180 °C. Furthermore, when the CaF2 content is increased from 3% to 11%, the number of nonbridging fluorine bonds (Al–F structure and Si–F structure) in the melt increases to 287, the number of bridging fluorine bonds (Al–F–Al structure, Si–F–Si structure, and Si–F–Si structure) is only 17, and the network rupture of fluorine ions in the system is larger than the network formation. Consequently, both the degree of polymerization and viscosity are reduced.

Terminal and bridging fluorine ligands in TiF4 as studied by 19F NMR in solids

To examine bonding nature of fluorine ligands in a metal coordinated system, 19F high-resolution solid-state NMR has been applied to TiF4, which bears both bridging and terminal fluorines. Observed 12 isotropic signals are assigned to 12 crystallographically different fluorines (6 terminal and 6 bridging fluorines) in TiF4 by referring to the calculated isotropic shifts using density functional theory (DFT). The isotropic chemical shift (δiso) for terminal F (FT) appears at high frequency (420–480 ppm from δ(CCl3F) = 0 ppm) with large shielding anisotropy Δσ ∼ 850 ppm. Whereas the δiso and Δσ values for bridging F (FB) are moderate; δiso ∼ 0–25 ppm and Δσ ∼ 250 ppm. The origin of the observed high-frequency shift for FT is ascribed to the second-order paramagnetic shift with increased covalency, shorter Ti–F bonds, and smaller energy difference between the occupied and vacant orbitals. Examination of the orientation of the shielding tensor relative to the molecular structure shows that the most deshielded component of the shielding tensor is oriented along the Ti–F bond. The characteristic orientation is consistent with a Ti–F σ bond formed by dYZ of Ti and pz of F. Further, we show that the selectively observed spinning sideband patterns and the theoretical patterns with the calculated Δσ and η (shielding asymmetry) values are not consistent with each other for FB, indicating deficiency of the present DFT calculation in evaluating Δσ.

The Structure of Hydrated Sodium Fluorophosphatozirconates According to NMR Data

23Na, 31P, 19F, 1H NMR and MAS NMR methods are used to study compounds Na2Zr3F2(PO4)4×3H2O (I), NaZr2F6PO4·4H2O (II), and NaZrO0.5FPO4·4H2O (III). It is established that fluorine in these compounds is coordinated to zirconium and occupies terminal positions in fluorophosphatozirconates I and III. Compound II contains both bridging and terminal fluorine atoms. Hypotheses are proposed concerning the nature of fluorophosphatozirconate crystal structure. The presence of translational motions of water molecules and sodium ions in compounds II and III has been established. The activation energy for the mobility of sodium ions in compound III is 0.24 eV.

Structural Studies of NaPO3–AlF3 Glasses by High-Resolution Double-Resonance Nuclear Magnetic Resonance Spectroscopy

The local structure of the model glasses (NaPO3)1–x-(AlF3)x (0 ≤ x ≤ 0.4), prepared by standard melt-cooling, was extensively investigated by high-resolution solid-state nuclear magnetic resonance (NMR) including advanced double-resonance techniques. This glass system offers the opportunity of studying five different heteronuclear distance correlations (Na–F, Na–P, P–F, Al–F, and P–Al) by 10 distinct double-resonance experiments, involving all of the constituent elements present. 27Al MAS-NMR data indicate that aluminum is predominantly six-coordinated. According to 27Al{31P} and 27Al{19F} rotational-echo double-resonance (REDOR) spectroscopic results, two to three Al–F and three to four Al–O–P linkages occur in these glasses, independent of composition x. 19F MAS-NMR spectra show the presence of terminal P-bound and Al-bound fluorine species. A small amount of fluorine bridging to two aluminum octahedra, which could be assigned based on 19F{27Al} and 19F{31P} REDOR experiments, was also detected. 19F{23N...

Combined Approach for the Structural Characterization of Alkali Fluoroscandates: Solid-State NMR, Powder X-ray Diffraction, and Density Functional Theory Calculations.

The structures of several fluoroscandate compounds are presented here using a characterization approach combining powder X-ray diffraction and solid-state NMR. The structure of K5Sc3F14 was fully determined from Rietveld refinement performed on powder X-ray diffraction data. Moreover, the local structures of NaScF4, Li3ScF6, KSc2F7, and Na3ScF6 compounds were studied in detail from solid-state 19F and 45Sc NMR experiments. The 45Sc chemical shift ranges for six- and seven-coordinated scandium environments were defined. The 19F chemical shift ranges for bridging and terminal fluorine atoms were also determined. First-principles calculations of the 19F and 45Sc NMR parameters were carried out using plane-wave basis sets and periodic boundary conditions (CASTEP), and the results were compared with the experimental data. A good agreement between the calculated shielding constants and experimental chemical shifts was obtained. This demonstrates the good potential of computational methods in spectroscopic assignments of solid-state 45Sc NMR spectroscopy.

Crystallization and luminescence properties of Eu3 +-doped ZrF4–BaF2–NaPO3 glass and glass ceramics

Fluorozirconate–phosphate glasses of the composition ZrF4–BaF2–NaPO3 doped with EuF3 have been investigated by the methods of differential thermal (DTA) and X-ray diffraction (XRD) analysis, nuclear magnetic resonance (19F NMR, 19F and 31P MAS NMR), luminescence spectroscopy, and scanning electron microscopy (SEM). The thermal behavior of the fabricated glasses is similar to that of fluorozirconate glasses – NaPO3 dopants decrease the glass transition temperature (Tg) from 300 down to 250°C and increase the glass stability to crystallization (ΔТ). Resonance lines in 19F NMR spectra correspond to the glass fluorozirconate network, whereas the 19F and 31P MAS NMR data indicate to the presence of bridge and end fluorine atoms in the structure and to low degree of depolymerization of phosphate chains. Thermal treatment in the temperature range Tg–Тх1 induces crystallization of nanosized particles, whose composition corresponds to β-BaZrF6. The SEM data indicate to the globular structure of glasses and synthesized glass ceramics, while the particle sizes are within the range 20–160nm. The intensity of luminescence of glasses doped with europium(III) increases upon doping with 2.5–10mol% of NaPO3 and decreases in glass ceramics. In glass and glass ceramics, europium ions are predominantly present in the fluorozirconate matrix.

Crystal structure and 121,123Sb NQR parameters of ammonium tridecafluorotetraantimonate(III) NH4Sb4F13

(NH4)Sb4F13 crystals (I) are synthesized and their crystal structure (tetragonal crystal system: a = 9.6431(2) A, c = 6.5503(2) A, V = 609.11(3) A3, Z = 2, d calc = 4.100 g/cm3, F(000) = 664, space group I4) is determined. The main structural units of I are tetranuclear anionic [Sb4F13]− complexes and [NH4]+ cations. The anionic complexes are built of four SbF3 groups linked together by tetrahedral bridging fluorine atom. At room temperature the (NH4)Sb4F13 crystals are isostructural to previously studied МSb4F13 (М = K, Rb, Cs, and Tl). The study of 121,123Sb NQR spectra of compound I is performed in a range of 77-370 K, which shows that when the temperature decreases (<250 K) the substance exhibits piezoelectric properties, as do other compounds of this group, but with a violation of their isostructurality.

K+···Cπ and K+···F Non-Covalent Interactions in π-Functionalized Potassium Fluoroalkoxides

Secondary interactions stabilize coordinatively demanding complexes of s-block metals [...]

Ion mobility, conductivity, structure, and phase transitions in K0.7M0.3SbF4 compounds with M=Rb, NH4

Ion mobility, phase transitions, structure, and conductivity in the K0.7M0.3SbF4 (M=Rb, NH4) compounds were studied by NMR spectroscopy, DSC, X-ray, and conductivity measurements. The predominant form in the ion motions resulting from the phase transition of high modification was diffusion of fluoride and ammonium ions above 450K. The high–temperature phases of K0.7M0.3SbF4 (M=Rb, NH4) are superionic, while their conductivity attains the values of ~10−2–10−4S/cm at 450–500K. The structures of α– and β–modifications of the K0.7Rb0.3SbF4 are monoclinic (space group P21/m). The main structural units in them are statistically substituting each other K+ and Rb+ cations and complex [SbF4]−∞1 anions linked into zigzag-like chains by bridge fluorine atoms. The nearest surrounding of each antimony atom contains five fluorine atoms, so that the antimony coordination polyhedron can be described, taking into account the lone electron pair, as a distorted SbF5E octahedron (ψ-octahedron).