Colin Russell Patrick

Fluorocyclohexanes. Part XVI. The six H-trifluoromethyldecafluoro- and two of the 2H,4H-trifluoromethylnonafluoro-cyclohexanes

Abstract Fluorination of benzotrifluoride by cobaltic fluoride at 260–280° gave, besides the fluorocarbon, the six possible tridecafluoromethylcyclohexane isomers, and two 2H,4H-dodecafluorides. Of the C 7 HF 13 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° (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°. The 1−CF 3 -ene gave hexafluoroglutaric acid on oxidation with alkaline potassium permanganate.

Polyfluorocycloalkenes. Part XVI [1]. Some addition reactions of 1-trifluoromethylnonafluorocyclohex-1-ene

Abstract Reactions with alcohols and base replaced the vinylic fluorine of 1-trifluoromethylnonafluorocyclohex-1-ene(I) by methoxy and ethoxy groups. Fluorination with cobaltic fluoride gave, from the former, a number of saturated polyfluoro-ethers. Oxidation of the alkoxy-cycloalkenes gave hexafluoroglutaric acid. Cycloalkene I gave which ammonia an imino-enamine, which was hydrolysed by dilute acid to a keto-enamine. I was defluorinated by heated iron to octafluorotoluene.

The effects of releases of chlorofluorocarbons on stratospheric ozone: The present position [1]

Abstract Current estimates of the depletion of the global content of ozone, due to the release of chlorofluoromethanes at present levels will be about 6% or less, but these are associated with changes in the vertical distributions of ozone. Recent analyses of ozone content show no evidence of depletion, consistent with the small estimates of depletion until about the present time. Relevant information is reviewed briefly.

The mixing properties of hexafluorobenzene with carbon tetrachloride and with perfluoromethylcyclohexane

Abstract Excess thermodynamic functions (free energies, enthalpies and entropies of mixing) have been obtained from measurements of vapour pressures, together with excess volumes of mixing, for mixtures of hexafluorobenzene with carbon tetrachloride and with perfluoromethyl-cyclohexane (tetradecafluoromethylcyclohexane). Deviations from thermodynamic ideality are large, although the systems are completely miscible. Critical temperatures of the mixtures are also reported. A correlation between the data, anticipated from a simple model for mixtures of asymmetric molecules, does not obtain.

The vapour pressures and excess free energies of mixing of the systems hexafluorobenzene-carbon tetrachloride and hexafluorobenzene-perfluoromethylcyclohexane

Abstract The vapour pressures of liquid mixtures of hexafluorobenzene with carbon tetrachloride and of hexafluorobenzene with perfluoromethylcyclohexane (tetradecafluoromethylcyclohexane) have been measured in the range of temperature 20–50 °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.