- THE VAPOUR PRESSURES AND EXCESS FREE ENERGIES OF MIXING OF THE SYSTEMS HEXAFLUOROBENZENE-CARBON TETRACHLORIDE AND HEXAFLUOROBENZENE-PERFLUOROMETHYLCYCLOHEXANE
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The vapour pressures of liquid mixtures of hexafluorobenezene with carbon tetrachloride and of hexafluorobenzene with perfluoromethylcyclohexane (tetradecafluoromethylcyclohexane) have been measured in the range of temperature 20-50 deg C, in a static system.These have been used to obtain the excess free energies of the mixtures.Both mixtures show large positive deviations from thermodynamic ideality, and also show azeotropic behaviour.
- Patrick, C. R.,Tomes, F.
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Read Online
- Prevention of anode fouling during the electrochemical perfluorination of aromatic carboxylic acid chlorides
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The electrochemical perfluorination of benzoyl chloride, p-substituted benzoyl chlorides and cyclo-hexane carboxylic acid chloride in anhydrous hydrogen fluoride (AHF) medium on nickel electrode is reported. Experimental conditions suppressing polymeric f
- Ilayaraja,Velayutham,Noel
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experimental part
p. 656 - 661
(2009/12/22)
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- Electrochemical fluorination of toluene and benzotrifluoride in the presence of triallylamine
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Electrochemical fluorination of benzotrifluoride in the presence of triallylamine as depolarizer was studied. The possibility of preparing perfluoromethylcyclohexane and its isomers with high current efficiency and substance yield in combination with perfluorinated tertiary amines was examined.
- Matalin,Kaurova,Berenblit,Gribel'
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p. 2090 - 2092
(2008/09/17)
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- Electrochemical fluorination of unsaturated sulfides and sulfones
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Electrochemical fluorination of some unsaturated sulfides and sulfones and their reactions with anhydrous HF were studied.
- Grigor'eva,Shainyan,Kaurova,Gracheva,Lesnevskaya,Barabanov
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p. 1095 - 1100
(2007/10/03)
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- DIRECT GAS-PHASE CATALYTIC FLUORINATION OF PARTIALLY FLUORINATED ORGANIC COMPOUNDS
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The fluorination of a wide range of polyfluorinated organic compounds with molecular fluorine in the gas phase in a layer of NiF2/support as catalyst was investigated.It was shown that the selectivity of fluorination of the series of fluoroolefins, acid fluorides, polyfluoroalkanes, and hydrogen-containing ethers can be greatly increased.The developed method was used on an industrial scale in the production of perfluorinated liquids.
- Zakharov, V. Yu.,Denisov, A. K.,Novikova, M. D.
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p. 1942 - 1945
(2007/10/03)
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- FLUORINATIONS WITH POTASSIUM TETRAFLUOROCOBALTATE. PART VIII. FLUORINATIONS OF TOLUENE AND OF PHENYLACETIC ACID
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At 340 deg C, toluene gave five 1-trifluoromethyl-substituted compounds: -2H,4H,5H-tetrafluorocyclohexa-1,4-diene (IX); -2H-4H/5H-hexafluorocyclohex-1-ene (X); -2H-octafluorocyclohex-1-ene (IV); -nonafluorocyclohex-1-ene (III); also perfluoromethylcyclohexane (II): traces of perfluorocyclohexane (I) were found.The 1-difluoromethyl-substituted analogues of these five were also obtained: - compounds XII, XV, VIII, VI, and V, respectively.A further five 1-difluoromethyl-substituted derivatives were found : -nonafluorocyclohex-3-ene (VII); an inseparable mixture of the -2H,4H- and -2H,5H-heptafluorocyclohex-1-enes (XI); -2H-3H/4H-hexafluorocyclohex-1-ene (probably) (XIV); and (difluoromethyl)benzene (XIII). Structures of the unknown products were established by analysis and by nmr and ir spectroscopy.Further, the key intermediate (XII) was oxidized to difluoromalonic acid, whilst compound IV was dehydrofluorinated, to give 2H-(difluoromethyl)tetrafluorobenzene (XXI), together with an inseparable mixture of 2H,4H- and 2H,5H-1-(difluoromethyl)pentafluorocyclohexa-1,4-diene (XX).Dehydrofluorination of mixed heptafluoro-enes XI afforded 2H-1-(difluoromethyl)hexafluorocyclohexa-1,4-diene (XVIII), and mixed 2H-1- and 1H-2-(difluoromethyl)hexafluorocyclohexa-1,3-diene (XIX). Difluoromethylundecafluorocyclohexane (V) did not dehydrofluorinate.Phenylacetic acid was fluorinated likewise, and gave a similar range of products, but also one (originally an acid fluoride?) which was converted to the methyl ester of tridecafluoro(cyclohexylacetic) acid (XVII).The probable pathway of the fluorination process could be worked out.
- Bailey, John,Plevey, Raymond G.,Tatlov, John Colin
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- FLUOROCYCLOHEXANES. PART XVII. DEHYDROFLUORINATIONS OF THE CIS AND THE TRANS ISOMERS OF 2H-1-(DIFLUOROMETHYL)DECAFLUOROCYCLOHEXANE
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2H-1-(Difluoromethyl)octafluorocyclohex-1-ene (I) and cobalt trifluoride at 165 deg C afforded 2H-1-(trifluoromethyl)octafluorocyclohex-1-ene (IV) and four decafluorocyclohexane derivatives: the cis (III), and trans (V), 2H-1-(trifluoromethyl)-; the cis (VII), and trans (VI), 2H-1-(difluoromethyl) compounds.Dehydrofluorination of VII, using aqueous potassium hydroxide, gave only one alkene, 1-(difluoromethyl)nonafluorocyclohex-1-ene (VIII).In a slower reaction VI afforded two alkenes, mainly VIII, but also an isomer, 1-(difluoromethyl)nonafluorocyclohex-2-ene (IX) (ratio 2:1).
- Bailey, John,Plevey, Raymond G.,Tatlow, John Colin
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p. 227 - 234
(2007/10/02)
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- FLUORINATIONS WITH COMPLEX METAL FLUORIDES. PART 9. FLUORINATIONS OF TOLUENE AND XYLENE DERIVATIVES BY MEANS OF CAESIUM TETRAFLUOROCOBALTATE(III)
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Benzotrifluoride at 320 deg C afforded some m-fluorobenzotrifluoride and octafluorotoluene (III), together with perfluoromethylcyclohexane (I), and also traces of 2H-heptafluorotoluene and 1-trifluoromethylnonafluorocyclohex-1-ene.Toluene itself gave (difluoromethyl)benzene, fluoro- and difluoro-methylpentafluorobenzene, difluoromethylundecafluorocyclohexane and (I); also traces of di- and tri-fluoromethylnonafluorocyclohex-1-ene: no benzotrifluoride or (III) were detected. 1,3-Bis(trifluoromethyl)benzene at 420 deg C gave 4,5,6-trifluoro-1,3-bis(trifluoromethyl)benzene, decafluoro-1,3-dimethylbenzene, and perfluoro-1,3-dimethylcyclohexane.Para-xylene at 350 deg C afforded 1,4-bis(difluoromethyl)tetrafluorobenzene, 1-difluoromethyl-4-trifluoromethyltetrafluorobenzene, decafluoro-1,4-dimethylbenzene (XIX), and perfluoro-1,4-dimethylcyclohexane (XVIII).Defluorination occurred to a significant extent on passage of the saturated cyclic fluorocarbons (I) and (XVIII) over the fully spent fluorinating agent (presumably caesium trifluorocobaltate) at ca. 400 deg C; the fluorocarbon arenes, (III) and (XIX) respectively, were obtained.
- Bailey, John,Plevey, Raymond G.,Tatlow, John Colin
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- Electron Affinities from Electron-Transfer Equilibria : A(-) + B = A + B(-)
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Determination of the equilibrium constants K1 for gas-phase electron-transfer equilibria with a pulsed electron beam high ion source pressure mass spectrometer led to the electron affinities of 34 compounds with EA's between 0.5 and 3eV.The compounds are mostly substituted nitrobenzenes, substituted quinones, and conjugated molecules containing oxygen atoms.The EA of smaller molecules like SO2, NO2, CS2, and CH3NO2 also were determined.The method is very well suited for rapid, accurate, routine determinations of electron affinities.A comparison with EA's determined with other gas-phase methods and EA's evaluated from polarographic half-wave reduction potentials and charge-transfer spectra in solution is made.The rate constants for a number of exothermic electron-transfer reactions were determined.Most of these proceed at near collision rates.Electron-transfer reactions involving perfluorinated compounds like perfluoromethylcyclohexane, perfluorocyclohexane, and sulfurhexafluoride do not follow this behavior.While the perfluoro compounds have high thermal electron capture cross sections, they do not accept electrons from A(-) of compounds A with lower electron affinity.The perfluoro anions do transfer electrons to compounds A with higher electron affinity, and the rate constants increase with EA(A) - EA(perfluoro compound).
- Grimsrud, Eric P.,Caldwell, Gary,Chowdhury, Swapan,Kebarle, Paul
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p. 4627 - 4634
(2007/10/02)
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- Electron affinity of SF6 and perfluoromethylcyclohexane. The unusual kinetics of electron transfer reactions A- + B = A + B-, where A = SF6 or perfluorinated cyclo-alkanes
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Measurements of the equilibria ( 1 ): A- + B = A + B- with a pulsed electron high pressure mass spectrometer lead to ΔG, ΔH, and ΔS.Equilibria involving SF6 as A and perfluoromethylcyclohexane C7F14 provide electron affinities E.A.(SF6) =1.05 +/- 0.1 eV and E.A.(C7F14) =1.06 +/- 0.15 eV.The kinetics of reactions (1) involving the above two compounds were studied.The rate constants kj for SF6- + B = SF6 + B- were found to increase with exothermicity of the reaction.The temperature dependence for k f was determined.B compounds leading to high exothermicities were associated with kj at the collision limit and essentially no temperature dependence.B of progressively lower electron affinity led to kf below the collision limit and negative temperature dependence, while B with the lowest E.A. but still leading to exothermic reaction produced lowest kf with positive temperature dependence.A model is provided explaining the above behavior.The known large change of geometry between SF6- and SF6 introduces an internal barrier in the reaction coordinate for the reactions ( 1 ) involving SF6.
- Grimsrud, E. P.,Chowdhury, S.,Kebarle, P.
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p. 1059 - 1068
(2007/10/02)
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- FREE RADICAL CHEMISTRY, PART 5. A NEW APPROACH TO THE SYNTHESIS OF PERFLUORINATED ETHERS
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Fluorinations of the free-radical adducts of fluorinated alkenes, to ethers, over cobalt trifluoride are described and perfluorinated ethers are obtained at temperatures in excess of 400 deg C.The effect of structure on the formation of perfluoroethers is outlined.
- Chambers, Richard D.,Grievson, Brian,Drakesmith, Frederick G.,Powell, Richard L.
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p. 323 - 340
(2007/10/02)
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- Reactions of Polyfluorocyclohexane- and Polyfluorocyclohexene-carbonitriles
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The vapour phase reaction of undecafluorocyclohexanecarbonitrile (1) with cobalt(III) or silver(II) fluoride caused stepwise saturation of the CN triple bond to give C6F11CF=NF and C6F11CF2NF2, whereas reaction in a sealed tube with silver(II) fluoride gave the azomethane C6F11CF2N=NCF2C6F11 and with silver(I) fluoride gave tris(undecafluorocyclohexyl)-s-triazine.Methylamine, isopropylamine, and dimethylamine with the nitrile (1) gave the corresponding amidines.Vapour phase fluorination of pentafluorobenzonitrile by cobalt(III) fluoride or potassium tetrafluorocobaltate(III) afforded the nitrile (1), together with nonafluorocyclohex-3-enecarbonitrile (4).The latter was oxidised by potassium permanganate to 3-cyanoheptafluorohexane-1,6-dioic acid.Nonafluorocyclohex-1-enecarbonitrile (2) underwent classical nucleophilic addition-elimination sequences with methanol and with sodium methoxide to give progressively octafluoro-2-methoxy-, heptafluoro-6,6-dimethoxy-, and hexafluoro-2,6,6-trimethoxy-cyclohex-1-enecarbonitrile, whilst with ammonia, 2-aminohexafluoro-6-iminocyclohex-1-enecarbonitrile was formed, again by stepwise addition-elimination.
- Phull, Gurjeet S.,Plevey, Raymond G.,Tatlow, John Colin
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p. 455 - 458
(2007/10/02)
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- POLYFLUORO-COMPOUNDS BASED ON THE CYCLOHEPTANE RING SYSTEM. PART 1. COMPOUNDS DERIVED FROM TRIDECAFLUOROCYCLOHEPTANE
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Partial fluorination of cycloheptane by cobaltic fluoride gave a mixture of polyfluorides, of which tridecafluorocycloheptane was present in significant proportions.With aqueous alkali this afforded dodecafluorocycloheptene, which with lithium aluminium hydride gave 1H-undecafluorocyclohept-1-ene.Each of these cyclo-olefins was oxidised to decafluoropimelic acid.Methanol/KOH reacted with dodecafluorocycloheptene to give mainly 1-methoxy-undecafluorocyclohept-1-ene together with ca 15percent of the 3-methoxy-isomer, and some 1,2-dimethoxydecafluorocyclohept-1-ene.The 1-methoxy-1-ene and cobaltic fluoride gave 1-methoxy- and 1-fluoromethoxytridecafluorocycloheptanone: the former was demethylated by sulphuric acid to dodecafluorocycloheptanone.The dichloro-adduct of the perfluoro-olefin was reduced by lithium aluminium hydride to a complex mixture, from which 1H/2H- and 1H,2H-dodecafluorocycloheptane were isolated.
- Oliver, John A.,Stephens, Robert,Tatlow, John Colin
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- FLUOROCYCLOHEXANES. PART XVI. THE SIX H-TRIFLUOROMETHYLDECAFLUORO- AND TWO OF THE 2H,4H-TRIFLUOROMETHYLNONAFLUORO-CYCLOHEXANES
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Fluorination of benzotrifluoride by cobaltic fluoride at 260-280 deg gave, besides the fluorocarbon, the six possible tridecafluoromethylcyclohexane isomers, and two 2H,4H-dodecafluorides.Of the C7HF13 compounds, only the cis-2H-, and the cis- and trans-4H-isomers could be isolated pure.The two 3H-isomers were made by pyrolysis of perfluoro(1-methyl-3-isopropylcyclohexane) in the presence of toluene.The trans-2H-isomer was made by further fluorination of one of the 2H,4H-dodecafluorides.Aqueous potash and the cis-2H-tridecafluoride gave 1-trifluoromethylnonafluorocyclohex-1-ene, which with stronger alkali hydrolysed to 1-carboxynonafluorocyclohex-1-ene.The cis- and trans- 2H and 4H-tridecafluorides were dehydrofluorinated by sodium fluoride at 320-380 deg (the cis-isomer of each pair reacted faster than the trans-: axial versus equatorial hydrogen) to give, respectively, the 1-trifluoromethylnonafluoro-ene and the 4-trifluoromethyl-isomer.The latter was isomerised to the former by sodium fluoride at 500-600 deg.The 1-CF3-ene gave hexafluoroglutaric acid on oxidation with alkaline potassium permanganate.
- Alsop, Derek J.,Burdon, James,Carter, Paul A.,Patrick, Colin R.,Tatlow, John Colin
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p. 305 - 316
(2007/10/02)
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- FLUORINATIONS WITH COMPLEX METAL FLUORIDES PART 8. RING REARRANGEMENT IN THE FLUORINATIONS OF QUINOLINE WITH CAESIUM TETRAFLUOROCOBALTATE AND WITH COBALT(III) FLUORIDE
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Fluorination of quinoline by caesium tetrafluorocobaltate at ca. 350 deg C afforded mainly a mixture of pentadecafluoro-2-azabicyclodec-1(2)-ene (E), and heptadecafluoro-1-azabicyclodecane (F), arising by skeletal rearrangement.Minor products were six polyfluorocyclohexapyridines (G-L) all with carbocyclic rings having the -(CF2)4 - moiety.Compound F was unreactive, but E was highly susceptible to nucleophiles, e.g. water and methanol.Isoquinoline was fluorinated similarly, but the only new product isolated was tridecafluoro-3-azabicyclodeca-1(6)-2-diene (R).The rearrangement occurring with quinoline prompted a re-examination of its fluorination by cobalt(III) fluoride.At ca. 350 deg C, compound F was the major product, with very little E: there were some ring-opened materials, the most important being tetradecafluoro-4-pentafluoroethyl-2-azaoct-2(Z)-ene (N).
- Plevey, Raymond G.,Rendell, Richard W.,Tatlow, John Colin
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p. 413 - 428
(2007/10/02)
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- Fluorination with Complex Metal Fluorides. Part 5. Fluorination of Nitriles over Caesium Tetrafluorocobaltate(III)
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Benzonitrile and the isomers of benzenedicarbonitrile (phthalo-, isophthalo-, and terephthalo-nitrile) have been fluorinated over caesium tetrafluorocobaltate(III) at elevated temperatures to give a mixtures containing undecafluorocyclohexanecarbonitrile.In addition the dinitriles gave decreasing yields (1,4- > 1,3- > 1,2-) of the corresponding cyclohexanedircarbonitriles.Some reactions (addition, defluorination, hydrolysis, and reduction) of undecafluorocyclohexanecarbonitrile are described.
- Phull, Gurjeet S.,Plevey, Raymond G.,Rendell, Richard W.,Tatlow, John Colin
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p. 1507 - 1511
(2007/10/02)
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