Abstract: A fully-fluorinated and fully saturated fluorocarbon, containing at least two condensed or non-condensed six-membered rings, seventeen carbon atoms and from 28 to 32 (inclusive) fluorine atoms in its molecule, and having a boiling point from 250.degree. to 265.degree. C.; provided that where the rings are non-condensed they are separated by not more than 4 carbon atoms. Such multi-ring C.sub.17 saturated-perfluorocarbons are produced by the saturation fluorination of the corresponding multi-ring hydrocarbons and are suitable for use as high-temperature vapour-soldering fluids, especially for use with solders melting above 200.degree. C.

Abstract: Increased stability is conferred on oil-in-water emulsions of perfluorocarbons by addition of a minor (0.1-5% w/v) amount of a fluorinated compound of higher boiling point than the perfluorocarbon being emulsified. The added fluorinated compound is preferably a perfluorinated saturated polycyclic hydrocarbon. The most preferred additive is perfluoroperhydrofluoranthene.

Abstract: A method of leak testing electrical or electronic components, by immersion in an inert liquid at a temperature above 100.degree. C., to detect any bubbles arising from the component, after which the component is removed from the liquid and drained, wherein according to the invention the liquid in which the component to be tested is immersed comprises predominantly perfluoroperhydrofluorene, C.sub.13 F.sub.22.

Abstract: Novel perfluorinated heterocyclic compounds have an azabicyclodecane structure with fused 5- and 7-membered rings incorporating a bridgehead nitrogen atom. They are prepared by cobalt (III) fluoride fluorination of quinolines or alkyl quinolines and are useful, when emulsified in aqueous media, as blood substitutes or organ perfusates, prior to transplant.

Abstract: A method of soldering wherein a component or components to be soldered, such as a printed circuit board and soldered preforms, are immersed in a vapor bath to melt the solder, following which the components are withdrawn from the vapor bath. In the method according to the invention, the vapor bath is composed predominantly of perfluorotetradecahydrophenanthrene (C.sub.14 F.sub.24).

Abstract: A process for the production of a fluorobenzonitrile wherein a chlorobenzonitrile having a chlorine atom in an ortho- or para- position with respect to a nitrile group is heated with an alkali metal fluoride at a temperature between 200.degree. and 250.degree. C., in the presence of sulpholane.

Abstract: A method of preparing a fluoronitrobenzene containing a fluorine atom in the para position with respect to the nitro group, comprising heating a polychloronitrobenzene or chloronitrobenzene containing a chlorine atom in the para position with respect to the nitro group with an alkali metal fluoride in the presence of sulpholane.

Abstract: Drying articles by displacement and/or solubilization of water with an organic solvent, by dipping the article into a body of solvent which is made effervescent, the said body of solvent being separated, except at the top and bottom thereof, from a non-effervescent body of solvent by means of a baffle wall which extends from a level above the bottom of the solvent container to substantially the surface level of solvent in the container, whereby a circulation of solvent is set up between the effervescent and non-effervescent bodies, and water is removed from the upper part of the non-effervescent body of solvent.