The preparation and properties of perfluoro-N-heptylbromine(N) tetrafluoride

Reactions of $\text{n}$C₇F₁₅Br with elemental fluorine at 0°C have produced perfluoro-$\text{n}$-heptylbromine(V) tetrafluoride ($\text{n}$-C₇F₁₅BrF₄). This derivative of BrF₅ was characterized by IR, ¹⁹FNMR, mass spectroscopy and elemental analysis. The reactions of $\text{n}$C₇F₁₅BrF₄ with 1,2-dichlorohexafluorocyclopentene-1 (C₅F₆Cl₂) and 1,2-dichlorooctafluorocyclohexene-1 (C₆F₈Cl₂) were used to demonstrate in the fluorinating ability of $\text{n}$C₇F₁₅BrF₄.     

Beitrage zur chemie des bromtrifluorids 1. Teil pentafluorphenylbrom(III)difluorid und -bis (trifluoracetat)

BrF₃ reacts with C₆F₅SiF₃ to form C₆F₅BrF₂, a volatile, colourless, and thermally stable solid, which melts at 35 – 36 °C without decomposition. Its chemical and spectroscopic properties are in contrast to the product described by Sams [1]. The reactivity of the BrF-bonds in C₆F₅BrF₂ allows displacement of fluorine by groups stable against oxidation. With trifluoroacetic acid anhydride C₆F₅Br[O(O)CCF₃]₂ is formed as the first stable carboxylate of Br(III).     

Taming elemental fluorine: Indirect use of fluorine for the synthesis of α-fluoroketones[1]

Fluorine and sodium trifluoroacetate react at ?75° to produce a variety of fluoroxy-compounds. Although it is possible to direct the reaction towards the formation of CF₃COOF or CF₃CF₂OF, mixtures may be used when only the electrophilic fluorine has to be attached to the molecule of interest. Such is the case of the reaction of enol-acetates with the mixture of the fluoroxy reagents. A wide variety of compounds, including steroids and containing various functional groups, were tested. In most cases the desired α-fluoroketones were obtained in good to very good yields. The new fluorine containing compounds are the compounds numbered $\text{2, 9, 11, 13, 15, 16}$ and $\text{20}$.     

Reactions of F-propene and its dimer with sodium dialkyldithiocarbamate

Sodium dialkyldithiocarbamates readily attacked $\text{F}$-propene to give S-(1,1,2,3,3,3-hexafluoropropyl)-N,N-dialkyldithiocarbamates, CF₃CHFCF₂SC(S)-NR₂, and $\text{Z}$ and $\text{E}$-S-(1,2,3,3,3-pentafluoropropenyl)-N,N-dialkyldithiocarbamates, CF₃CFCFSC(S)NR₂. The pyrolysis of the former compound quantitatively gave the dialkylthiocarbamoyl fluorine, R₂NC(S)F, while the latter compound and sodium tetraphenylborate formed the corresponding 1,3-dithiolan-2-ylium tetraphenylborate. $\text{F}$-2-Methyl-2-pentene also reacted with sodium dialkyldithiocarbamate to give (CF₃)₂CHC[SC(S)NR₂]CFCF₃. The mechanism of this reaction is supposed to involve a 1,4-RSF-elimination.     

Coordination chemistry of higher oxidation states. 10 [1]. Oxofluoroanions of osmium(VIII) [OsO4F2]2− and [OsO3F3]−

Trioxotrifluoroosmates(VIII) M[OsO₃F₃] (M = Cs, Rb, K) have been prepared by direct combination of OsO₃F₂ and the appropriate alkali fluoride MF. The reaction of OsO₄ with M′F (M′ = Cs, Rb) in aqueous solution produces the tetraoxodifluoroosmates(VIII) M′₂[OsO₄F₂]. On the basis of their vibrational spectra the assignment of a $\text{fac}$ (C_3v) structure to [OsO₃F₃]^? and a $\text{cis}$ (C_2v) to [OsO₄F₂]^2? is proposed. The electronic spectra of the anions have been recorded and are interpreted using the optical electronegativity concept.     

Preparation of fluoroalkylated benzoheterocycles using F-2-methylpropene

Several benzoheterocyclic compounds carrying a CH(CF₃)₂ group were prepared by the reactions of $\text{F}$-2-methylpropene with ortho-bifunctional benzenes. The reactivity and reaction mode of $\text{F}$-2-methylpropene in these reactions were compared with those of $\text{F}$-propene.     

The synthesis of highly fluorinated phthalonitrile resins and cure studies

The reactions of the potassium salts of 1,3- and 1,4-bis(2-hydroxy-hexafluoro-2-propyl) benzene $\text{1}$ and $\text{2}$ with tetrafluorophthalonitrile $\text{3}$ afforded three isomeric products in each case with reaction at the 4-position of $\text{3}$ predominating. When each mixture was submitted to the usual thermal conditions for phthalocyanine formation [1–5], the expected characteristic color change (blue or green) did not develop.Evidence was procured from our study which indicated that fluorine substituted on the phthalonitrile moieties hindered phthalocyanine formation. Instead, as an alternative reaction, some nucleophilic displacement of fluorine from the aromatic rings by the cyano substituents appeared to have occurred.     

The electronic structure of the BrF3 and BrF5 molecules

Ionization potentials of the BrF₃ and BrF₅ molecules have been calculated by the SCF DV Xα method. The calculations hale been carried out in numerical Hartree-Fock basis sets, or, to be more specific, in bases that are extensions of these bases since “virtual” bromine 4d-functions are added to the numerical HF bases. The results are used for the interpretation of the experimental PDS of these compounds.     

The hydrolysis of dibromofluoromethyltriphenylphosphonium bromide

Hydrolysis of [Ph₃$\text{P}\text{+}$PCFBr₂]Br^? afforded a high yield of dibromofluoromethane and triphenylphosphine oxide. Hydrolysis in the presence of a radioactive isotope of bromine gave evidence that the mechanism of this reaction proceeds $\text{via}$ the dibromofluoromethide ion and not $\text{via}$ a bromofluorocarbene intermediate.     

Bis(perfluoroorganyl)bromonium salts [(RF)2Br]Y (RF = aryl, alkenyl, and alkynyl)

Bromonium salts [(R_F)₂Br]Y with perfluorinated groups R_FC₆F₅, CF₃CFCF, C₂F₅CFCF, and CF₃C≡C were isolated from reactions of BrF₃ with R_FBF₂ in weakly coordinating solvents (wcs) like CF₃CH₂CHF₂ (PFP) or CF₃CH₂CF₂CH₃ (PFB) in 30-90% yields. C₆F₅BF₂ formed independent of the stoichiometry only [(C₆F₅)₂Br][BF₄]. 1:2 reactions of BrF₃ and silanes C₆F₅SiY₃ (Y = F, Me) ended with different products - C₆F₅BrF₂ or [(C₆F₅)₂Br][SiF₅] - as pure individuals, depending on Y and on the reaction temperature (Y = F). With C₆F₅SiF₃ at ≥−30 °C [(C₆F₅)₂Br][SiF₅] resulted in 92% yield whereas the reaction with less Lewis acidic C₆F₅SiMe₃ only led to C₆F₅BrF₂ (58%). The interaction of K[C₆F₅BF₃] with BrF₃ or [BrF₂][SbF₆] in anhydrous HF gave [(C₆F₅)₂Br][SbF₆]. Attempts to obtain a bis(perfluoroalkyl)bromonium salt by reactions of C₆F₁₃BF₂ with BrF₃ or of K[C₆F₁₃BF₃] with [BrF₂][SbF₆] failed. The 3:2 reactions of BrF₃ with (C₆F₅)₃B in CH₂Cl₂ gave [(C₆F₅)₂Br][(C₆F₅)_nBF_4−n] salts (n = 0-3). The mixture of anions could be converted to pure [BF₄]⁻ salts by treatment with BF₃·base.     

The hydrolysis of bromodifluoromethyltriphenylphosphonium bromide [1]

Hydrolysis of [Ph₃$\text{P}\text{+}$CF₂Br]Br^? afforded a high yield of bromodifluoromethane and triphenylphosphine oxide. Hydrolysis in the presence of a radioactive isotope of bromine or sodium iodide gave unequivocal evidence that the mechanism for this reaction proceeds through a difluorocarbene intermediate.     

Organothallium compounds XII NMR spectra of some polyfluorophenylthallium (III) compounds

The PMR and ¹⁹F NMR spectra of the complexes R₂TlBr (R = C₆F₅, $\text{o}$-HC₆F₄, $\text{m}$-HC₆F₄, 3,5-H₂C₆F₃, or 3,6-H₂C₆F₃ and R₃Tl(diox) (R = C₆F₅, $\text{m}$-HC₆F₄, or 3,5-H₂C₆F₃; diox = 1,4-dioxan) have been recorded. Proton and fluorine chemical shifts, thallium-proton, thallium-fluorine, fluorine-fluorine, and fluorine-proton coupling constants, and thallium substituent chemical shifts are given and discussed     

Pyridine•BrF3, the missing link for clean fluorinations of aromatic derivatives

This work demonstrates the unique features of the never used before Py?BrF(3) complex in the field of aromatic organic fluorinations. The main disadvantage of the noncomplexed BrF(3) is the fact that usually, in addition to the desired fluorination, a parallel electrophilic aromatic bromination takes place as well. Use of the Py?BrF(3) complex reduces this electrophilic bromination, which is observed with most reagents based on fluorine and bromine [BrF].     

Bonding information in tungsten(VI) compounds from directly bonded fluorine and fluorophenoxy subtituents

The series of compounds (FC₆H₄O)_nWF_6-n, where n = 1-6 and F is meta or para to oxygen, has been prepared and all fluorine nmr chemical shifts determined. The W-$\text{F}$, para-$\text{F}$, and meta-$\text{F}$ resonances all shift upfield as a function of n with approximate relative sensitivities of 1, 1/20, and 1/30, respectively. All chemical shifts are also found to be sensitive to molecular stereochemistry, with subtituents trans to oxygen shifted to higher field than those trans to fluorine. ¹⁹F data is also reported for the complete series (C₆H₅O)_nWF_6-n     

Synthese d'isoquinoleines F-alkyl substituees

In this paper we report preparation of isoquinolines F-alkyl substituted in $\text{1}$ position by R_F chains such as CF₃, C₃F₇, C₅F₁₁, C₇F₁₅. These compounds are obtained by catalytic deshydrogenation of the F-alkyl-1 dihydro-3,4 isoquinolines which are prepared by cyclodeshydratation of the N-(phenyl-2 ethyl) F-amides and N- (phenyl-2 propyl) F-amides. These last compounds are obtained the N-allyl F-amides by Friedel-Crafts type reaction.The preparations as a whole yield 26 new F-alkyl compounds.     

Zur kenntnis von [O2]22+[Ti7F30]2−

[O₂]²⁺₂[Ti₇F₃₀]^2? has been obtained by reaction of TiO₂ with a mixture of fluorine and oxygen (p_F2/O2 ≈ 300–3500 atm., t ≈ 300–450°C) either as colourless powder or in form of colourless, clear needles. From single crystal studies the spacegroup is P$\text{3}$ - C_3i¹ (No. 147) with a = 10.19₂, c = 6.50_o Å, Z = 1. The crystal structure has been refined to R = 0.086 [R_w = 0.058] (748 unique reflexions [F_o > 2σ(F_o)]). From the structure determination [O₂]²⁺₂[Ti₇F₃₀]^2? has isolated columns of partially distorted [TiF₆] octahedra (- column structure) which are connected only quite loosely by (disordered) O₂⁺ cations. ν_O2+ is at 1857 cm^?1, the magnetic moment μ_eff = 2.35 B.M. (295 K) is quite as expected for a ‘spin-only’ case.     

Fluorine-containing seven-membered benzoheterocycles derived from hexafluoropropene oligomers

4-Fluoro-2-($\text{F}$-ethyl)-3-($\text{F}$-methyl)-1, 5-benzoxazepine was prepared by reaction of $\text{F}$-2-methyl-2-pentene with 2-aminophenol in the presence of triethylamine in diethyl ether. The reaction of $\text{F}$-2,4-dimethyl-3-heptene with 2-aminophenol in dimethylformamide gave 7-($\text{F}$-1-methylethyl)-8- ($\text{F}$-ethyl)-9,14-benzoxazepino[4,3-b]1,6-benzoxazepine. Several ortho-bifunctional benzenes reacted similarly with $\text{F}$-2-methyl-2-pentene and $\text{F}$-2,4-dimethyl-3-heptene to give the corresponding seven-membered benzoheterocycles.     

Radical additions of xenon difluoride to cis- and trans-1-phenylpropenes: comparison with trichloramine and iodobenzene dichloride

We would like to report data which support a free radical pathway for reaction of xenon difluoride (XeF₂) with alkenes in organic solvent. Radical intermediates have been proposed for reaction of XeF₂ to double bonds. For example, a radical pathway was suggested for the gas phase reaction of XeF₂ to ethylene and propene [1]. Zupan speculated on a radical cation pathway for the acid catalyzed reaction of XeF₂ with alkenes but gave no experimental evidence for this mechanism [2,3]. Radical cation intermediates were demonstrated for the reaction of XeF₂ to aromatics by Filler [4]. Acid catalyzed ionic reactions to unsaturated hydrocarbons have been reviewed [5].Zupan and Pollak have shown that alkenes do not react in aprotic solvent with XeF₂ at low concentrations of alkene unless acid catalyst is present [3]. However, we observed that illumination of a dilute solution of $\text{cis-}$ or $\text{trans}$-1-phenylpropenes (I) or (II) in methylene chloride at 0° with a 270 watt sunlamp produced IIIa and IIIb in less then two hours (Table). Furthermore, at high concentration of (I) and (II), a spontaneous reaction occurred in the dark between XeF₂ and these styrenes. The reaction conditions for both of these reactions imply a radical mechanism — the latter a molecule-induced pathway.     

The reactions of aromatic compounds with bromine trifluoride (2): Octafluoronaphthalene

The reaction of bromine trifluoride with octafluoronaphthalene has been investigated, from which was obtained decafluoro-1,2-benzocyclohexa-1,4-diene, 2-bromo-undecafluorotetralin and a mixture of dibromotetradecafluorobicylo [4,4,0] decene isomers. Dehalogenation and reduction gave decafluoro-1,2-benzocyclohexa-1,3-diene in addition to the 1,4-diene and 2$\text{H}$-undecafluorotetralin, a similar mixture being obtained from the dibromo decene. The reactions of the dienes and bromofluorotetralin with methoxide ion have also been studied.     

Photodissociation of alkyl bromides

The branching ratios for the production of Br(4²P_{$\text{1}\text{2}$}) following the broadband flash photolysis of the alkyl bromides, CH₃Br and C₂H₅Br, and the perfluorinated molecules, CF₃Br, C₂F₅ Br and n-C₃F₇ Br, have been determined using time-resolved atomic absorption spectroscopy. The production of electronically excited bromine atoms is shown to be inefficient in the case of the alkyl bromides while the perfluorinated molecules yield decreasing amounts of Br(4²P_{$\text{1}\text{2}$}) as the molecular complexity increases, i.e., CF₃Br > C₂F₅Br > C₃F₅Br > C₃F₇. It is also shown that the hydrogenated bromides deactive electronically excited atoms almost two orders of magnitude faster than do the perfluorinated bromides.