Abstract: A fully fluorinated and fully-saturated heterocyclic organic compound of general formula ##STR1## wherein the saturated rings F are fully fluorinated, and where the Rf radical is selected from perfluoro-alkyl groups, perfluoro-alicyclic groups, and mixed perfluoro-cycloalkyl-alkyl groups, and wherein the Rf radical contains from 1 to 10 carbon atoms inclusive. The compounds are high temperature heat transfer fluids.

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: 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board and soldered preforms, are immersed in a vapor bath to melt the solder, following which the components are withdrawn from the vapor bath.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).