Bridging Fluorine Research Articles

Hydrolysis of tin(II) fluoride and crystal structure of Sn4OF6

The hydrolysis of SnF2 in concentrated aqueous solution resulted in the formation of the tin(II) fluoride oxide, Sn4OF6. This is the first evidence for the formation of a basic tin(II) fluoride from an aqueous system. The crystal structure of Sn4OF6 has been determined using single-crystal X-ray diffraction and refined by full-matrix least-squares analysis to R= 0.0199. The compound crystallises in the orthorhombic space group P212121 with a= 16.088(3), b= 10.681 (2), c= 4.940(1)A and Z= 4. The structure consists of a three-dimensional polymeric network of bridging fluorine and oxygen atoms. Tin is present in four distinct sites one showing tetragonal-based pyramidal geometry while the others all show trigonal-pyramidal geometry with a fourth bridging fluorine atom at 2.4–2.5 A. The non-bonding electrons are stereochemically active and appear to point into irregular channels which run parallel to the c axis.

OsO3F2 and OsO2F4, Preparation and Crystal Structures

AbstractThe new method for preparing OsO3F2 is presented. Its crystal structure reveals a polymeric chain structure with distorted octahedral geometry for the OsO3F3 units and symmetrical, non‐linear fluorine bridges. The OsO3F3 unit has a facial geometry. This structure is not in accord with predictions on the molecular structure of OsO3F2. OsO2F4, obtained from KrF2 and OsO4, crystallizes in the space group P61 forming a sixfold helical chain arrangement of nearly octahedral OsO2F4 molecules. Oxygen or fluorine atoms are partially disordered. The cis orientation of the two oxygen atoms is established by means of NMR, vibrational spectroscopy, and X‐ray data.

Adducts of manganese-(III) and -(IV) fluorides with antimony pentafluoride

With the starting materials Mn, MnF 2 or MnF 3 with Sb, SbF 3 and SbF 5, the following amorphous adducts are formed by fluorination at elevated temperature and under pressure: MnF 3 · SbF 5 (75–100 °C, 30–60 bar F 2); 4MnF 4 · SbF 5 (110–350 °C, 60–1000 bar F 2); MnF 4 · SbF 5 (250–330 °C, 230–350 bar F 2, deposited in part of vessel cooled to 30–60 °C). With traces of oxygen present, 8MnF 4 · SbF 5 was found instead of 4MnF 4 · SbF 5. Conductivity measurements and infrared spectra indicate that the compounds are not ionic, but contain covalent fluorine bridges. No trace of a pentavalent [MnF 4] +[SbF 6] − was found.

Polymeric tin(II) fluorocomplexes

Tin(II) fluoride compounds are known to exist either as salts (with tin(II) being in anionic or cationic sublattices) or as neutral complexes. Some are polymeric with fluorine bridges. We wish to deal with the problem of synthesis and stereochemistry polymers of tin(II) fluorides. The main structural fragments in tin(II) fluorides are the chains (FSn) n combined in different ways. There are two types of Sn(II) coordination polyhedra, the first being pentagonal and the second a trigonal bipyramid with the lone electron pair (LEP) in equatorial planes. Two cationic compounds, [Sn 6F 10][TiF 6] ( I) and [Sn 6F 10][NbOF 5] ( II), a neutral material Sn 2(SO 4)F 2·H 2O ( III) and two anionic compounds [Co(H 2O) 6] (SnF 3) 2 ( IV) and K[Co(NH 3) 6](SnF 3) 2(NO 3) 2·1/2H 2O ( V) were synthesized and investigated by X-ray, IR, NMR and DTA. The effect of LEP of tin(II) on the crystal structure of the synthesized compounds has been considered and different distortion of angles FSnF and bonds SnF have been pointed out. Analysis of corresponding distances and angles in other complexes shows that the mean SnF distance in anionic complexes is smaller than in cationic ones, but the mean FSnF angles for anions are larger than those for cations. The steric chemical activity of a LEP on the Sn(II) environment in anions is lower than in cations. This can be explained by additional shielding of a LEP by extra electrons in the anions. Some methods (choice of cations, pH, condition of crystallization, stoichiometry, etc.) for the synthesis of different types of polymeric tin(II) fluorides as cationic, anionic, neutral and anionic with isolated SnF 3 − groups are proposed.

Three-membered cyclic fluoronium ions in gaseous ion-neutral complexes

The fluoriranium ion (CH2CH2*, la) is shown to exist as an intermediate within ion-neutral complexes derived from the molecular ions of @-fluorophenetole (8). Ion-neutral complexes containing the isomeric ion CH3CHF+ (2a) also occur. The parent neutral 8 favors the gauche conformation, and theoretical calculations show that the radical cation 8'+ and the conjugate acid ions should also favor their gauche conformers. NMR analysis of the neutral fluoroethylenes from deuterated analogues of 8'+ show that fluorine bridging to form la and hydride shift to form 2a take place competitively and not sequentially. Nearly the same ratios of ClH2DF loss to C2HD2F loss are observed for the radical cations and from the MD+ conjugate acid ions. By contrast, free C2H2D2P ions quenched by chloride abstraction from (CH3),CCI have the structure 29, in which sequential transpositions have occurred. The difference between free ions and ions within complexes is ascribed to the millionfold difference in lifetimes under the experimental conditions.

Structural characterization of hypervalent fluoride and oxofluoride derivatives of xenon and tellurium and iodine

The study of fluoro- and oxofluoro-anions and cations having coordination numbers higher than six has been of particular interest and is exemplified by the fluoride ion donor and electron pair acceptor properties of the oxofluorides of xenon. The X-ray crystal structure of XeOF 3 +SbF 6 − has been determined. The XeOF 3 + cation is shown to have two fluorine bridges to neighboring SbF 6 − anions, resulting in an AX 6E VSEPR arrangement around xenon in the solid state. The solution 17O NMR spectrum along with the 17O/ 18O isotope shift ratio in the 129Xe spectrum of the XeOF 3 + cation have also been obtained. The fluoride ion donor properties of XeOF 2 and the formation of the XeOF + cation are also discussed. The electron pair acceptor properties of XeOF 4, XeOF 2 and XeO 3 in the presence of nitrogen bases have been investigated by NMR spectroscopy. The XeOF 4·CH 3CN adduct has been isolated as a crystalline solid and its structure also appears to be best represented as a distorted octahedral (AX 6E) arrangement. In collaboration with Dr. K.O. Christe and Dr. W.W. Wilson (Rockwell International), a number of hypervalent anions having coordination numbers exceeding six have been prepared and characterized. The IOF 6 − anion has been characterized as its N(CH 3) 4 + salt by X-ray crystallography, vibrational spectroscopy and in solution by NMR spectroscopy. The X-ray structure shows that the anion is distorted from C 5v point symmetry by means of a puckering of the five fluorines in its equatorial plane. The structures of the N(CH 3) 4 + salts of the TeOF 6 2−, XeOF 5 −, XeF 7 − and TeF 7 − anions will also be described. The Lewis acid properties of XeF + and XeOTeF 5 + have been investigated in the presence of the nitrogen base F 5TeNH 2. The novel XeN bonded F 5TeN(H)Xe + and F 5TeN(H)XeNCH + cations have been synthesized in anhydrous HF and characterized by 1H, 15N, 19F, 125Te and 129Xe NMR spectroscopy.

Pentacoordinate anionic bis(siliconates) containing a fluorine bridge between two silicon atoms. Synthesis, solid-state structures, and dynamic behavior in solution

Pentacoordinate anionic bis(siliconates) containing a fluorine bridge between two silicon atoms. Synthesis, solid-state structures, and dynamic behavior in solution

The effects of interplay of shielding, dipolar coupling, and indirect coupling tensors in the Tin-119 NMR spectra of solid triorganyl tin fluorides

Tin-119 magic-angle-spinning NMR spectra have been recorded for four solid triorganyl tin fluorides R 3SnF (R = methyl, isobutyl, phenyl, and mesityl). The centerbands give evidence of the polymeric nature of the first three compounds, which have fluorine bridges and pentacoordinate tin. The spinning sidebands show the influence of the interplay of shielding, dipolar coupling, and indirect coupling tensors. The theory of such interplay for AX 2 spin systems with coaxial tensors of axial symmetry is developed. Its application to the spectra discussed here results in values for shielding tensor components and dipolar coupling constants (including the pseudo-dipolar contribution) and thence (in principle) in estimates for the indirect coupling anisotropy ΔJ. The values of ΔJ may be given unambiguously since the absolute sign of the isotropic indirect coupling is known, but X-ray data on Sn-F distances are not yet known sufficiently well to make full use of the NMR results. Data from spinning-sideband analysis of trimesityltin fluoride are also given.

Phenylantimony(V) fluoride halides: isolation and crystal structures of SbPh2Br2F·SbPh2Br3, (SbPh2BrF)2O and SbPh3Cl1.8F0.2

Oxidation of diphenylantimony fluoride with chlorine leads to diphenylantimony trichloride as the only isolable product, while the corresponding reaction with bromine gives, in addition to SbPh2Br3, the bromide fluorides, Sb2Ph4Br5F, SbPh2Br2F, Sb2Ph4Br3F3 and SbPh2BrF2. The structure of the first compound has been confirmed by X-ray diffraction as a fluorine-bridged diantimony compound, SbPh2Br2F·SbPh2Br3, where the antimony atoms are, respectively, in trigonal-bipyramidal and distorted-octahedral co-ordination. Hydrolysis during attempts to obtain crystals of the second compound produced the oxygen-bridged (SbPh2BrF)2O, which contains a strong intramolecular fluorine bridge, again giving antimony atoms in both trigonal-bipyramidal and octahedral co-ordination. As an alternative approach to the preparation of mixed chloride fluorides, reactions between diphenylantimony trichloride and KF, AgF and arsenic trifluoride were investigated. There was no reaction with the first two reagents but the product with arsenic trifluoride was a disordered mixed halide, shown by X-ray crystallography to be SbPh3Cl1.8F0.2.

An unusual complex derived from MoCl 3(THF) 3 and AgBF 4 in acetonitrile: Synthesis and structure of [MO 2(μ-F)(NCCH 3) 8O 2][BF 4] 3

Reaction of MoCl 3(THF) 3 with 3 equiv of AgBF 4 in refluxing acetonitrile produces the unusual solvated Mo IV-oxo complex [Mo 2(μ-F)(NCCH 3) 8O 2[BF 4] 3 ( 1) as a result of oxidation by silver(I), as well as abstraction of both a fluoride ion from [BF 4] − and an oxygen atom from THF or adventitious water. Compound 1 has been investigated by 1H and 19F NMR, IR and UV-vis spectroscopy, electrochemistry and X-ray crystallography. Single crystal X-ray data collected at − 92 ± 2°C revealed that 1 is monoclinic, space group P2/ n with a = 11.776(4), b = 12.293(7), c = 12.497(7) Å, β = 100.90(4)°, V = 1776(1) Å 3 and Z = 2. Final refinement led to R = 0.038 and R w = 0.059. The structural core of the molecule consists of the unusual group [OMoFMoO] 3+ for which the angle MoFMo is 165.0°. The pyramidal MoN 4 units around each molybdenum(IV) centre are staggered with respect to one another, and as a result of the basal N plane being 0.27 Å from the molybdenum centre, the acetonitriles are canted towards the centre of the molecule forming a “cupped” central region around the bridging fluorine atom. This fluoride-bridged structure is unique among molybdenum(IV) dimers, and is one of only several documented examples in molybdenum chemistry.

The X-ray structure of bis-2,2-dimethyl-6,6,7,7,8,8,8-heptafluorooctane-3,5-dionatolead(II): an eight-coordinate dimer with bridging fluorine atoms

The title complex, a useful precursor for a range of lead oxides, has an unusual structure involving dimeric, eight-coordinate lead units bridged by the fluorine atoms of the ligand; the compound is unusually volatile which may in part be explained by the structure.

The crystal structures of ammonium pentafluorozirconates NH 4ZrF 5 ·H 2O and NH 4ZrF 5

Proceeding from the structural depolymerization concept one of us suggested [1] and the systematization of fluorozirconate crystal structures performed on its basis [2] to allow to predict the type of crystal structure for uninvestigated compound, it was concluded [2] that NH 4ZrF 5 · H 2O should have a infinite chain structure formed from octacoordinated zirconium polyhedra, one site in which is occupied by the H 2O coordinated molecule. Work [2] also suggests that compared with the structure of NH 4ZrF 5 · H 2O, that of NH 4ZrF 5 should be more polymerized, each polyhedron of ZrF 8 containing essentially two terminal and six bridge fluorine atoms. Our determination of the crystal structures of NH 4ZrF 5 · H 2O and NH 4ZrF 5 confirmed the conclusions made in [2]. The crystals NH 4ZrF 5 · H 2O are monoclinic, space group P2 1/n : a = 10.723(2), b = 7.529(1). c = 6.761(1) Å, β = 78.24(2) o, Z = 4. The Zr-F distances range from 2.010 to 2.249 Å, and the Zr-O(H 20) bond is equal to 2.261 Å. Monocline NH 4ZrF 5 crystals, sp. gr. P2 1/b: a = 7.973(9), b = 7.923(7), c = 7.911(7) Å, γ = 121.68(12) o, Z = 4, isostructural to TlZrF 5 [3], built of NH 4 + cations and (ZrF 5) n− n layers formed by combining ZrF 8 groups by a common edge and four common apices.

ChemInform Abstract: Structures of X2F4, from Carbon to Lead. Unsaturation Through Fluorine Bridges in Group 14.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The Structure of IF

The structure of the IF ion can be described as a distorted octahedron with C3v, symmetry, and thus-—in contrast to that of BrF—it is in keeping with the electron pair repulsion model. Whereas IF in crystals of (CH3)4NIF6 forms a dimer by weak fluorine bridges (see Figure), in the case of a smaller cation a tetramer is found, in analogy to the isoelectronic XeF6.

Structures of X2F4, from carbon to lead. Unsaturation through fluorine bridges in Group 14

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructures of X2F4, from carbon to lead. Unsaturation through fluorine bridges in Group 14Georges Trinquier and Jean Claude BarthelatCite this: J. Am. Chem. Soc. 1990, 112, 25, 9121–9130Publication Date (Print):December 1, 1990Publication History Published online1 May 2002Published inissue 1 December 1990https://doi.org/10.1021/ja00181a014RIGHTS & PERMISSIONSArticle Views106Altmetric-Citations39LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Fluorine-substituted ferracyclopentadiene complexes with an unprecedented fluorine bridge between boron and carbon [Erratum to document cited in CA112(5):36104g

Fluorine-substituted ferracyclopentadiene complexes with an unprecedented fluorine bridge between boron and carbon [Erratum to document cited in CA112(5):36104g

Electronic structure of Pc2Lu and (PcAlF)n oriented thin films using angle resolved photoelectron spectroscopy

Ultraviolet photoelectron spectra have been measured for the radical phthalocyanine dimer, Pc2Lu, and the fluorine bridge stacked phthalocyanine polymer (PcAlF)n. Previous workers have shown that both materials can, under appropriate conditions, be prepared in a well characterised, highly oriented thin film form. Thus, samples for this work were prepared by in situ sublimation at very slow evaporation rates onto crystalline substrates to try to maximise the degree of sample orientation. The angle dependence of the spectra were measured and the sample structure subsequently examined using high resolution TEM. The TEM results show that the (PcAlF)n films have a much higher level of orientation than the Pc2Lu films and this is reflected by the angle dependences of the UPS measurements. The spectra for (PcAlF)n are very similar to measurements on most other simple phthalocyanine compounds and have a small angular dependence. The spectra for Pc2Lu show almost no angular dependence. Again the spectra are broadly similar to that of other Pc's with two significant differences, the lowest energy peak is split and the whole spectra is shifted to lower energy. This result will be discussed in terms of simple molecular orbital ideas. The effect of air on the spectra of both materials was examined and the spectra of (PcAlF)n was found to be particularly sensitive. Attempts to determine the position of the lutetium orbitals by varying the light frequency around the lutetium resonance energies was attempted but no significant variation in the spectra was observed.

ChemInform Abstract: Fluorine‐Substituted Ferracyclopentadiene Complexes with an Unprecedented Fluorine Bridge Between Boron and Carbon.

AbstractThe title complexes (III) are the first examples of any type of compound with a fluorine atom bridging between C and B atoms.

Fluorine-substituted ferracyclopentadiene complexes with an unprecedented fluorine bridge between boron and carbon

The authors recently reported the preparation of ferracyclopentadiene complexes, which are derivatives of the well-known complex Fe{sub 2}({mu}-CH{sub 2})(CO){sub 8}. Pettit has shown that the latter compound readily reacts with alkynes to form binuclear allyl complexes, and it was thus of interest to determine if complex 1 would incorporate alkynes in a similar fashion. However, as reported herein, this reaction takes a most surprising course, to yield fluorine-substituted ferracyclopentadiene complexes that form by fluoride donation from BF{sub 4}{sup {minus}} and which have been crystallographically shown to possess an unprecedented fluorine atom bridge between carbon and boron atoms. Furthermore, it has been found that the fluorine substituent is readily abstracted by the BF{sub 3} group when this complex is treated with nucleophiles.

ChemInform Abstract: The Gas‐Phase Structures of Perfluoroquinolizidine and Perfluorotripropylamine

Abstract The geometric structures of perfluoroquinolizidine (PFQ) and perfluorotripropylamine (PFTA) have been studied by gas electron diffraction. For PFQ only the configuration with the nitrogen lone pair trans to the bridging fluorine atom was observed. Fluorination causes lengthening of the CC bonds and shortening of the NC bonds relative to those in piperidine and flattening of the six-membered rings. For PFTA a large number of rotational isomers has been considered. A structure with C 3 symmetry and planar configuration at the nitrogen atom best reproduces the experimental electron-diffraction intensities. Strong steric interactions in this molecule are further indicated by the increase in the NC and (CC) mean bond lengths [about 0.03 A relative to N (CF 3 ) 3 and C 2 F 6 ] and by opening of the NC 1 C 2 angle to 118.1(12)°.