Thionyl Tetrafluoride and Pentafluorosulfur Hypofluorite

Thionyl tetrafluoride and pentafluorosulfur hypofluorite can be prepared by the fluorination of thionyl fluoride. The product distribution obtained upon fluorination appears to be dependent not only upon the reaction conditions, but on whether a source of fluoride ion is present. Fluorination of thionyl fluoride over a hot platinum gauze or in a Monel pressure reactor produces thionyl tetrafluoride, whereas fluorination in the presence of cesium fluoride or a silver fluoride catalyst jdelds pentafluorosulfur hypofluorite. The role of the fluoride ion in the fluorination has not been conclusively established however, the avail- 

Although thionyl tetrafluoride and pentafluorosulfur hypofluorite can be prepared by fluorination in a flow reactor, the procedures described here are performed in a static system. This method offers several advantages. The metal equipment needed is commercially available, and the ability to closely control the stoichiometry of the reactions results in the formation of the products in high purity. However, the amount of material that can be prepared in one run is limited. Thionyl tetrafluoride may also be prepared in good yield by the oxidation of sulfur tetrafluoride. This method is also easy to carry out if the requisite high-pressure equipment is available. 

The procedures for the preparation of thionyl tetrafluoride and pentafluorosulfur hypofluorite are essentially the same, with one important difference the use of a catalyst. The apparatus employed in the preparations consists of several Monel pressure vessels (which have been prefluorinated at 150-200 ), a standard glass vacuum line equipped with several large calibrated storage bulbs (1- or 2-1.), a partial fractionation train, and several ball-joint connections on the main manifold. All the joints and stopcocks on the vacuum line are lubricated with Kel-F-90t grease, and all mercury manometers are covered with Kel-F-10 oil,t which has been well outgassed. The vacuum line is connected to a fluorine metering system and a water 

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