Fluorosulfonic Acid Research Articles

Geometries and vibrational frequencies of oxyacids and carboxylic acids. a study on structural and vibrational effects

The equilibrium geometries of the acids H 3BO 3, H 2CO 3, HNO 2, HNO 3, HPO 3, HClO 4, H 2SO 4, CH 3SO 3H, CF 3SO 3H, FSO 3H, ClSO 3H, H 2SeO 4, H 3PO 4. HCO 2H, HCOOOH and C 6H 5CO 2H, and of the anions H 2BO − 3, HBO - 3, BO 3− 3, HCO 3 −, HSO 4 −, CH 3SO 3 −, CF 3SO 3 −, FSO 3 −, CISO 3 −, HSeO 4 −, HPO 4 2−, H 2PO 4 −, PO 4 3−, HCO 2 −, HCOOO − and C 6H 5CO 2 − were determined at the self-consistent field (SCF) level, employing polarized split-valence basis sets. The MP2/6-31G ∗∗ level was adopted to optimize the geometries of H 3BO 3, HBO 2, H 2CO 3, HNO 3, HPO 3, HNO 2, HCO 2H and HCOOOH; those of the anions H 2BO 3 −, HBO 3 2−, HCO 3 −, HCO 2 − and HCOOO − were studied at the MP2/6-31G ∗∗ level. The last section of the study reports the results of SCF calculations on the hydrogen-bonded complexes (HCO 2 −) (H 2O), (CO 3 2−) (H 2O) and (HCO 3 −) (H 2O).

Electrochemical addition of fluorosulfonic acid to perfluoro-2-methyl-3-isopropyl-2-pentene

Electrolysis of fluorosulfonic acid in the presence of perfluoro-2-methyl-3-isopropyl-2-pentene yields the products of addition of HSO3F at the double bond — 2-hydro-3-fluorosulfatoperfluoro-2-methyl-3-isopropylpentane and 2-fluorosulfato-3-hydroperfluoro-2-methyl-3-isopropylpentane. The formation of monofluorosulfates probably includes the stage of one-electron reduction of the initial olefin.

Intercalation chemistry of graphite fluorides

Graphite fluorides of the general composition CF n , with n  0.25−1.0, are found, according to X-ray diffraction and X-ray photoelectron studies, to contain graphitic zones which allow oxidative intercalation by bis(fluorosulfuryl)peroxide, S 2O 6F 2, as well as intercalation by fluorosulfuric acid HSO 3F and trifluoromethylsulfuric acid HSO 3CF 3. The reactions produce materials of the general composition CF n (SO 3F) m or CF n (HSO 3X) m , with X  F or CF 3. While intercalation of S 2O 6F 2 into the graphitic zones results in the formation of first-stage intercalation products in all instances, higher-stage materials form with HSO 3F and to an increased degree with HSO 3CF 3, particularly when graphite fluorides with low fluorine contents are used. Interestingly, according to their X-ray photoelectron spectra, intercalation of all three reagents causes an increase in the polarity of the C—F bond; the oxidized graphitic zones appear to increase while the fluorine ls binding energies suggest an increased ionic character.

Generation of gold ions in the solid state or in fluorosulfuric acid solution and their identification by ESR

The partial pyrolysis of gold(III) fluorosulfate, Au(SO 3 F) 3 , at temperatures below 145 o C allows the generation of Au 2+ defects in the solid residue by reductive elimination of SO 3 F radicals. Solvated Au 2+ is obtained by the reduction of Au(SO 3 F) 3 in HSO 3 3F solution by gold powder at 65 o C

Internal nucleophilic termination in biomimetic acid mediated polyene cyclizations: stereochemical and mechanistic implications. Synthesis of (.+-.)-Ambrox and its diastereoisomers

Treament of structurally related trienols and dienols with an excess of fluorosulfonic acid in 2-nitropropane at -90°C afforded diastereoisomeric mixtures of the odoriferous norlabdane oxides.

β-Fluorosultones: synthesis, reactivity, structure and uses

β-Fluorosultones are unique cyclic compounds formed by addition of sulfur trioxide to fluorinated olefins. Their extensive chemistry is due, in large part, to the ease of forming reactive isomeric fluorosulfonyl polyfluorocarbonyl fluorides or polyfluoroalkene fluorosulfates. Their reactions can lead via multipathways to a large number of structurally modified fluorosulfonic acids or precursors such as fluoroalkyl sulfonyl-fluorides, esters, amines, and alkoxides.

The 119Sn Mössbauer and solid-state NMR and the crystal and molecular structure of tin(II) bisfluorosulfate, Sn(OSO2F)2

The reaction of tin(II) fluoride with fluorosulfuric acid has been shown to produce tin(II) bisfluorosulfate. Crystals of Sn(OSO2F)2 are monoclinic, space group P21/c with a = 5.195(1), b = 9.709(1), c = 13.861(1) Å, β = 110.12(1)°, Z = 4, R = 0.029, and Rw = 0.030 for 1461 unique reflections. The structure consists of a three-dimensional framework of fluorosulfate groups linked by O—Sn—O bridges with the two crystallographically independent fluorosulfates acting as tridentate bridging ligands between tin atoms. There are four short bonds (Sn—O = 2.338(3), 2.350(3), 2.398(4), and 2.427(3) Å) and two longer ones (Sn—O = 2.695(3) and 2.702(3) Å) around tin. The four short bonds have a disphenoidal, AX4E, primary geometry with the lone pair occupying an equatorial site. If the two longer interactions are also considered the geometry is distorted octahedral, AX4Y2E. Two more non-bonding contacts of 3.420(4) and 3.319(4) Å complete an approximately dodecahedral arrangement of oxygen atoms around the tin. The fluorosulfate groups deviate significantly from C3υ symmetry and have the mean dimensions, S(1)—O = 1.419(4), S(1)—F = 1.541(4), S(2)—O = 1.435(3), S(2)—F = 1.539(3) Å, O—S(1)—O = 114.3(2)°, F—S(1)—O = 104.1(3)°, O—S(2)—O = 114.2(2)°, and F—S(2)—O = 104.1(2)°, respectively. The solid-state 119Sn nmr spectrum shows only one single resonance with a shift of −1534 ppm which is substantially different from that of a solution in HSO3F. The 119Sn Mössbauer spectrum shows an unresolved quadrupole splitting as a result of a distorted environment around tin, produced by the stereochemically active non-bonding electron pair. Key words: tin(II) bisfluorosulfate, 119Sn Mössbauer, solid-state nmr, X-ray crystallography

The anodic behavior of saturated hydrocarbons in fluorosulfuric acid: Part II. Oligomerisation of the three lightest alkanes

The oligocondensations of methane, ethane and propane have been studied by allowing an excess of these hydrocarbons to react on carbenium ions, derived from these alkanes (and obtained by their gentle oxidation at an anode) dissolved in HSO 3F + HF mixture (1:1) which is a good non-nucleophilic solvent. Since these three compounds are not chemically oxidized by HSO 3F into the corresponding carbenium ions, unlike all the other saturated hydrocarbons, an activation method has been developed. Thus the electrooxidation of these gases was conducted successfully in the mixture HSO 3F + HF (1:1) with anodes made of platinum or vitreous carbon “V10”. Ethane was formed from methane and propane, isobutane and isopentane were formed from ethane. The oligocondensation of methane comes to a stop, to give predominantly ethane due to the low electrooxidation rate of this last compound compared with that of methane. In the case of propane, isobutane, isopentane and a mixture of branched-chain hexanes were obtained. A high pressure electrolysis cell has been developed.

Electrochemical fluorosulfation of tetrafluoroethylene

Electrooxidation of certain fluoroolefins on platinum and glass-carbon in fluorosulfonic acid has been studied. The large difference in oxidation potentials of tetrafluoroethylene and the fluorosulfate anion makes it possible to carry out fluorosulfation via an ECEC mechanism. Potentiostatic preparative electrolysis at limiting-current potentials for oxidation of tetrafluoroethylene (E=1.5 V) yields a mixture of α,ω-bis-fluorosulfates which is almost quantitative with respect to current, the main component being 1,2-bis(fluoro-sulfato)tetrafluoroethane.

Fluoro- and fluorosulfato derivatives of the early transition metals

Binary metal fluorosulfates of the type M(SO 3F) 4 (M = Ti, Zr and Hf) are obtained by metal oxidation with bis(fluorosulfuryl)peroxide, S 2O 6F 2, in fluorosulfuric acid, HSO 3F, according to: M + 2S 2O 6F 2 ▪M(SO 3F) 4, M = Ti, Zr or Hf Both zirconium and hafnium tetrakis(fluorosulfate) are high melting white solids which are virtually insoluble in HSO 3F while Ti(SO 3F) 4, a viscous greenish oil, shows limited solubility. All three are fluorosulfate acceptors, and salts of the type Cs 2[M(SO 3F) 6] are easily obtained under milder conditions according to: M + 2CsSO 3F + 2S 2O 6F 2 ▪Cs 2[M(SO 3F) 6], M = Ti, Zr or Hf The binary fluorosulfates M(SO 3F) 5 (M = Nb or Ta) are obtained in solution only, again by metal oxidation with S 2O 6F 2 in HSO 3F, or in form of cesium salts of the type Cs 2[M(SO 3F) 7] or Cs[M(SO 3F) 6] as reported previously (1). It is now found that both niobium and tantalum are also oxidized by S 2O 6F 2 in the absence of HSO 3F, but complete removal of S 2O 2F 2 from the very viscous oils is not possible without decomposition. Oxidation of Nb or Ta in the presence of MF 5 (M = Nb or Ta), according to: nMF 5 + (5−n)M + (5−n)/2 S 2O 6F 2 ▪5MF n(SO 3F) 5−n, M = Nb or Ta provides a facile route to fluoride-fluorosulfates of Nb and Ta.

Stabilisation of the novel gold-cations Au 2+ and Au(CO) 2+ in superacids

The solution of gold tris(fluorosulfate), Au(SO 3F) 3, in fluorosulfuric acid, HSO 3F, is a very strong monoprotonic superacid [1]. In this system gold(III) can be reduced under mild conditions by CO [2] or gold metal [3]. The reduction of Au(SO 3F) 3 with CO is described by the overall reaction: ▪ The action of gold metal on Au(SO 3F) 3 in HSO 3F yields the solvated Au 2+ cation, which has been characterised by ESR spectra. The ESR signal is strongly dependent on the Au 2+/Au(SO 3F) 3 ratio. From the saturated solution a red-yellow precipitate of diamagnetic Au[Au(SO 3F) 4] is formed at room temperature. Paramagnetic Au 2+ ions are also generated as lattice defects in solid Au(SO 3F) 3 by pyrolysis. The resulting materials are studied by ESR and magnetic susceptibility measurements and represent together with Au 2+ (solv) the first unambiguous evidence for the existence of true Au 2+ cations. In addition, a solid complex is obtained where [Au(CO) 2] + is stabilised by Sb 2F 11 −. The linear cation [Au(CO) 2] + is fully characterized by IR-, Raman- and 13C-NMR-spectroscopy. The CO stretching frequencies for [Au(CO) 2] + are the highest reported so far. Its force field is compared to those of other carbonyls and the dicyanoaurate(I) ion, [Au(CN) 2] −. The kinetics of the CO-exchange of [Au(CO) 2] + in HSO 3F-solution has been studied.

Oxidizing properties of transition metal hexafluorides towards p-block elements and polymeric μ-fluoro(phthalocyanine)aluminium(III)

The behaviour of UF 6, MoF 6 and WF 6 towards the p-block elements Se, As, Sb and Bi has been studied using MeCN as solvent. The results obtained, together with previous work involving I 2, Br 2 and Te with MoF 6 and UF 6 [1], have enabled a detailed picture of p-block element redox chemistry in MeCN to be obtained. Complex cation, hexafluorometallates (V) have been isolated for all the elements examined and structures for the cations are proposed on the basis of spectroscopic studies. Oxidation of [Al(Pc)(μ-F)] n Pc = phthalocyanine dianion, by the hexafluorides which has been reported previously using microcrystalline material [2], occurs also in the presence of MeCN. Soluble products are obtained whose electronic spectra are very similar to those of [Al(Pc)(μ-F)] n dissolved in the protonic acids CF 3CO 2H, CF 3SO 3H and HSO 3F. Thin films of [Al(Pc)(μ-F)] n, grown by evaporation onto single crystal KCl or silica wafers, are also oxidised when exposed to UF 6, MoF 6 or WF 6 vapours. The oxidised films are stable in the absence of moisture unlike those obtained using I 2 as oxidant, where the redox reaction appears to be reversible. We thank the SERC for support of this work.

X-ray - PES in graphite intercalation chemistry and the intercalation behaviour of graphite fluoride

X-ray photo electron spectroscopy (X-ray-PES) is employed in the study of acceptor graphite intercalation compounds (GIC's) together with X-ray powder diffraction. For stage 1 to 3 graphite fluorosulfates observed shifts of the C 1s level relative to graphite are interpreted in terms of two opposing effects: a Fermi level shift to lower binding energies and a core level shift due to the partial positive charge of the graphite lattice. In addition, various levels like O 1s, F 1s or S 2p 3/2 of the molecular intercalates are studied. In addition, graphite fluorides of the composition CF x x = 0.25 − 0.80 is found to have both graphitic zones and partially oxidized layers which allow oxidative and non-oxidative intercalation by either bis(fluorosulfuryl) peroxide, S 2O 6F 2, or the protonic acids HSO 3F and HSO 3CF 3. The resulting intercalation compounds are studied by X-ray powder diffraction and X-ray PES.

Janusene and tetrafluorojanusene in superacid media; radical cation formation and chemistry

Both janusene 1 and the facial tetrafluorojanusene undergo one electron oxidation in FSO 3H.SbF 5 (1:1) ‘magic acid’/SO 2ClF and in HF.SbF 5 (1:1)/SO 2ClF at low temperature to give persistent radical cations. Rapid dimerization → polymerization follows. Stable σ-complexes of protonation were not observed at all. In the less oxidizing milder superacid FSO 3H/SO 2, neither 1 nor 2 are fully protonated or oxidized. Radical cation-mediated condensation of 1 is much more rapid than for the fluorinated analog. Two structurally different dimeric compounds could be isolated in quenching experiments. The extent of transannular donor-acceptor interactions in the facially fluorinated janusenes were compared with those for the tropylium-containing janusene, fluorinated [2.2] paracyclophane and its stable σ-complex.

Fluorosulfate derivatives of divalent gold

The reduction of gold(III) fluorosulfate, Au(SO 3F) 3 with either gold powder or carbon monoxide, in fluorosulfuric acid, HSO 3F, yields gold(II) fluorosulfate as a yellow-red solid in high yield. Based on magnetic measurements and vibrational spectra, formulation as mixed valency Au(I) Au(III)- (SO 3F) 4 is suggested. Evidence from ESR measurements for a solvated, paramagnetic Au(II)-species in the supernatant solution is obtained and discussed.

Superacidic FSO3H/HF catalyzed butane isomerization [1

Superacid catalyzed isomerization of butane was studied. Highly efficient isomerization of butane to 2-methylpropane (isobutane) was achieved using fluorosulfuric acid containing up to 5% of hydrogen fluoride acting as a protic co-acid. The isomerization when carried out in excess FSO3H at 21 ° C in a flow system gave ∼70% conversion to 2-methylpropane with generally less than 3% cracking. When 2-methylpropane was isomerized under similar conditions about 12% butane was formed. Attempted isomerization of pentane and hexane with prolonged reaction times in a static system results in predominant protolytic cleavage (cracking).

Study of the propagation of short fissures: Dabezies, B. Establishment Technique Central de l'Armement Report No PB90-178278/XAB 10 May 1989 65 pp (in French)

The molecular geometry of fluorosulphuric acid methyl ester is consistent with the structures of other simple sulphones as determined by microwave spectroscopy and electron diffraction. The results include ra(S=O) = 1.410 · 0.002, ra(S-F) = 1.545·0.006, ra(S-O) = 1.558·0.007 A, ∠F-S-O = 96.8·0.6, ∠F-S=O = 106.8·0.5, ∠O-S=O = 109.5 ± 0.6, ∠O=S=O = 124.4 · 0.7, and ∠S-O-C = 116 5·0.7. As regards the conformational properties, both microwave spectroscopy and electron diffraction revealed the presence of the anti form, while a gauche form could not be excluded.

Recent investigations on precipitation phenomena of aluminium alloys: Murakami, Y. J. Jpn. Inst. Light Met. May 1989 39, (5), 364–377 (in Japanese)

The molecular geometry of fluorosulphuric acid methyl ester is consistent with the structures of other simple sulphones as determined by microwave spectroscopy and electron diffraction. The results include ra(S=O) = 1.410 · 0.002, ra(S-F) = 1.545·0.006, ra(S-O) = 1.558·0.007 A, ∠F-S-O = 96.8·0.6, ∠F-S=O = 106.8·0.5, ∠O-S=O = 109.5 ± 0.6, ∠O=S=O = 124.4 · 0.7, and ∠S-O-C = 116 5·0.7. As regards the conformational properties, both microwave spectroscopy and electron diffraction revealed the presence of the anti form, while a gauche form could not be excluded.

Fluoroaliphatic esters of fluorosulfonic acid. 1. Reactions of higher fluoroolefins with electrochemically generated peroxydisulfuryl difluoride

The electrolysis of fluorosulfonic acid in the presence of perfluoro-2-alkenes in an electrolyzer without a diaphragm results in the formation of a mixture of products, whose composition is determined by both the anodic and cathodic processes.

ChemInform Abstract: The Development of Highly Branched Carboxylic Acids and Their Production.

Copper (I) and silver carbonyl catalysts were prepared in strong acids such as sulfuric acid, hydrogen fluoride, boron trifluoride-hydrate and fluoro sulfuric acid. Carbonylation of olefins, alcohols, dienes, diols, aldehydes and saturated hydrocarbons were carried out under atmospheric pressure and at room temperature by using copper (I) carbonyl catalyst, and tert-carboxylic acids were prepared in high yield.The highly hindered carboxylic acid was prepared from isobutylene oligomer. The industrial process of highly hindered carboxylic acid was established by using sulfuric acid-phosphoric acid-water mixed solvent in the recycle use of catalyst, and pilot plant started in 1988. This carbonylation method is available to the production of another compound also.The derivatives of highly hindered carboxylic acid is stable to hydrolysis and heat. The usages of this hindered carboxylic acid are paint, microgel, surfactant, stabilizer, initiator of polymerization, agricultural chemicals.