Thionyl fluorides

Submitted by W. C. Smith and E. L. Muetterties Checked by J. D. Park and Robert Settine  

Thionyl fluoride can be prepared by the reaction of thio-nyl chloride with metal fluorides such as zinc(II) fluoride1 and arsenic (III) fluoride,2 and with metal fluorosulfites.3 It is also obtained by the action of hydrogen fluoride upon a mixture of tetrasulfur tetranitride and copper(II) oxide4 and by the reaction of hydrogen fluoride with thionyl chloride in the absence of6 or in the presence of6 antimony(V) fluoride as catalyst. Another method and the simplest on a laboratory scale involves the reaction of antimony(III) fluoride with thionyl chloride in the presence of antimony ) chloride as catalyst.7 This last procedure is described below. 

The reaction is carried out in a 500-ml. four-necked flask fitted with a mercury-sealed stirrer, thermometer, dropping funnel, and condenser. The condenser is connected in series to two glass traps, J fitted with stopcocks, and then to a calcium chloride drying tube. 

The apparatus is thoroughly dried, and flushed with nitrogen the reaction flask is charged with 280 g. (1.57 mols) of antimony(III) fluoride and 120 g. (0.524 mol) of antimony- 

The colorless liquid product collected in the trap is purified by distillation in a glass still at atmospheric pressure. The yield is about 55%. Mass spectrometric analysis indicates that the product is 99.5% pure, with air and silicon tetrafluoride as the trace impurities present. 

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Chemical Properties. Sulfur tetrafluoride reacts rapidly with water to give hydrofluoric acid and thionyl fluoride [7783 2-8] ... 

Sulfur forms two main series of oxohalides, the thionyl dihalides OS X2 and the sulfuryl dihalides 02S X2. In addition, various other oxofluorides and peroxofluorides are known (p. 688). Thionyl fluorides and chlorides are colourless volatile liquids (Table 15.14) OSBt2 is rather less volatile and is orange-coloured. 

Thionyl fluoride, as by-product in sulfur tetrafluoride reactions, 41, 105 toxidty of, 41,105 Thiophene-2-OL, 43, 55 2(5H)-Thiophenone, 43, 55 Thiosemicarbazide, in synthesis of 1,2,4 triazole, 40, 99 reaction with formic acid to yield l-formyl-3-thiosemicarbazide, 40,99... 

Nitryl Fluoride Nitrosyl Fluoride Thionyl Fluoride Sulfuryl Fluoride... 

Reaction with hydrofluoric acid forms sulfurous oxyfluoride (thionyl fluoride), SOF2 ... 

Solid sulphur, selenium, and tellurium inflame in fluorine gas at ordinary temp. sulphur burns to the hexafluoride, SF6. The reactivity of sulphur or selenium with fluorine persists at —187°, but tellurium is without action at this temp. Hydrogen sulphide and sulphur dioxide also burn in the gas—the former produces hydrogen fluoride and sulphur fluoride. Each bubble of sulphur dioxide led into a jar of fluorine produces an explosion and thionyl fluoride, S0F2, is formed but if the fluorine be led into the sulphur dioxide, there is no action until the sulphur dioxide has reached a certain partial pressure when all explodes. If the fluorine be led into an atm. of sulphur dioxide at the temp, of the reaction, sulphuryl fluoride, S02F2, is formed quietly without violence. Sulphuric acid is scarcely affected by fluorine. 

Sulfur tetrafluoride is a colorless, highly reactive, toxic, and corrosive gas which has an odor resembling that of sulfur dioxide. It has an LD50 of 50 ppm (4 h) and at higher concentrations the clinical signs are severe animals receiving lethal amounts show pulmonary edema on autopsy. Sulfur tetrafluoride liberates hydrogen fluoride and thionyl fluoride on exposure to moisture and causes burns on unprotected skin areas.1... 

The charged autoclaves are heated, preferably in a rocking muffle furnace. After heating for the required period, the autoclave is allowed to cool to ambient temperature, and excess sulfur tetrafluoride, thionyl fluoride and other volatile byproducts are vented from the autoclave and absorbed in an alkaline absorbent. If the gaseous products are of interest they are condensed... 

Thionyl fluoride has also been obtained in excellent yield by the interaction of liquid hydrogen fluoride and nitrogen sulphide in the presence of a little copper oxide, the reaction being best effected in a copper bomb at 100° C. The gas, which issues on opening the bomb, can be collected in a receiver cooled by liquid air.1... 

When not in contact with glass, e.g. in a tube of platinum, thionyl fluoride can be heated to a white heat without appreciable decomposition. Water causes a slow hydrolysis ... 

The combustion of fluorine in moist hydrogen sulphide or the interaction of fluorine and dry hydrogen sulphide in a glass vessel (the last-named supplying the necessary oxygen) also gives rise to a mixture of sulphuryl fluoride with thionyl fluoride, sulphur hexafluoride and silicon fluoride.3... 

Heated to 120° C. in a closed platinum vessel, hydrogen fluoride and nitrogen sulphide unite to form a red liquid, which readily decomposes into its constituents. In the presence of traces of moisture, thionyl fluoride is formed. Dry hydrogen chloride reacts with nitrogen sulphide according to the equation 1... 

Tetrakis (N-dihydropyridyl) aluminate, 64 Thionyl fluoride, 462 Torsional strains, 71 19-Tosyloxyandrost-4-ene-3,17-dione, 198... 

Thionyl Fluoridate 2,2,2-Trifluoro-l-trifluoromethyl-ethyl ElOa. 251 (S-Cl - S-F)... 

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