Antimony trifluoride, reactions

Procedure. Finely powdered antimony trifluoride is placed in the reservoir of the feed. Phosphorus oxychloride and then antimony pentachloride are placed in the reaction vessel. The temperature of the bath is maintained, thermostatically, at 75° and the pressure kept at 190-200 mm., and the antimony trifluoride is then added slowly from the feed. The distillates in the traps are united and fractionated. The distillate, up to b.p. 90°/760 mm., is collected and carefully refractionated, giving pure phosphorus oxydichlorofluoride, b.p. 54° (20 per cent yield). 

In view of the high toxicity of (II), it seemed that the sulphur analogue, dimethylaminosulphonyl fluoride (VI), might be of some interest. We therefore studied the fluorination of dimethylaminosulphonyl chloride. The reaction with potassium fluoride was incomplete, and that with zinc fluoride unsatisfactory, but that with antimony trifluoride using benzene as a solvent proved to be very satisfactory, and an 80 per cent yield of (VI) was obtained. Physiological examination showed that (VI) caused no irritation when small animals were exposed to a concentration of 1 mg./l. for 10 min., and no deaths took place. With the sulphonyl chloride at the same concentration, lacrimation and nasal irritation were caused no deaths were recorded, and all the animals recovered almost immediately on being removed from the chamber. 

Several methods are available for the synthesis of CFsSBr. Either CF2BrSBr is fluorinated at 100°C with antimony trifluoride (186) or CFsSCl is reacted with bromine cyanide over activated carbon at 70°C (86). Apart from that it is obtained always contaminated with CFsSSCFj in the reaction between Hg(SCF8)2 and bromine (31) these compounds react at 0°C to give a mixture composed of 56% CFsSBr and 45% CFjSSCFs. 

Sb is oxidized by nitric acid, forming a gelatinous precipitate of bydrated antimony pentoxide. It does not react with cold dilute sulfuric acid. However, reaction occurs in bot concentrated acid an oxysulfate of indefinite composition and low acid-solubdity is formed. It reacts with bydrofluoric acid to form soluble antimony trifluoride and pentafluoride. Hydrochloric acid in the absence of air does not readily attack tbe metal however, finely divided antimony reacts with hot concentrated acid forming chloride salt. 

Reactions with antimony trifluoride, SbFs in the presence of antimony pen-tachloride, SbCls, form mixed halides of compositions GeClsF, GeCl3F2, GeCl2F2, and GeClFs. 

Fluorophosphites are prepared by a two step sequence. The initial step is the reaction of phenolic materials with phosphorus trichloride to prepare a chlorophosphite intermediate. The chlorophosphite is then treated with a fluoride source to convert the chloro- intermediate into the desired fluorophosphite product. Many different fluoride sources have been described in the literature including anhydrous hydrogen fluoride, anhydrous potassium fluoride, and antimony trifluoride. While any of these fluoride sources can be used successfully, we have found that antimony trifluoride (10) works well for small scale, lab preparations. 

A number of routes to thiocarbonyl fluoride that do not involve tetrafluoro-dithietane have been developed. In one (50), phosgene is chlorinated to give tri-chlorosulfenyl chloride, which is converted to chlorodifluorosulfenyi chloride by reaction with antimony trifluoride, and the fluorinated compound is then dehalogenated by reaction with tin. 

It must be concluded, therefore, that fluorophosphines are strongly reducing, a fact which was confirmed in further attempts at their preparation, using different reagents in the fluorination of chlorophosphines. There was either no reaction at all under the experimental conditions—e.g., with alkali fluorides in benzene as a solvent—or the trivalent phosphorus in the starting chlorophosphine was readily converted to the quinquevalent state—e.g., when phenyldichlorophosphine reacted with sodium fluoride in the presence of an antimony trioxide catalyst in a polar solvent such as acetonitrile to give phenylphosphonic difluoride. Recent Russian work showed that phenyldichlorophosphine was converted into phenyltetrafluoro-phosphorane, C6H5PF4, when it reacted with antimony trifluoride (34),... 

In the course of a study of the formation of fluorophosphoranes from chloro-phosphines (22) we observed one exception in the compound chloromethyldi-chlorophosphine, which reacted smoothly with antimony trifluoride to give the flammable fluorophosphine, C1CH2PF2, under conditions where many other chloro-phosphines were invariably converted into fluorophosphoranes. As this fluorophosphine is readily available, its interaction with a metal carbonyl derivative was studied, and cycloheptatriene molybdenum tricarbonyl, obtained from the reaction of molybdenum hexacarbonyl with cycloheptatriene (I, 2), was chosen as a starting compound. 

A slightly exothermic reaction took place when the antimony trifluoride was gradually added to the chlorophosphine. The temperature in flask I was maintained sufficiently high to allow distillation of the volatile fluorination products immediately after their formation. Material boiling at 35° to 55° was carefully redistilled at a slow rate. Chloromethyldifluorophosphine was collected, boiling at 33.5°-34.5°. Yield was 29.7 grams (83.5%). 

Organic compounds Organic fluorine compounds arc made by reaction of the corresponding alkane chloro-compounds with silver fluoride, mercurous fluoride, antimony trifluoride, titanium tetrafluoridc. and the arene fluoro-compounds by the diazo-reaction using hydrogen fluoride, and otherwise. The effect of the continued replacemenl of hydrogen atoms by fluorine atoms is an initial increase in reactivity, followed by a reversal of this effect, so lhal the highly substituted compounds arc relatively inert, See also Fluorocarbon. 

SWARTS REACTION. Fluorination of organic polyhalides with antimony trifluoride (or zinc and mercury fluorides) in the presence of a trace of a pentavalent antimony salt. 

Replacement of either one or two of the chlorines of carbon tetrachloride by fluorine can be achieved readily with antimony trifluoride containing some antimony pentachloride. The reaction stops after two chlorines have been replaced. The antimony trifluoride can be regenerated continuously from the antimony chloride by addition of anhydrous hydrogen fluoride ... 

The behavior of a number of chlorine derivatives of methane, ethane, and propane toward antimony trifluoride activated by the trifluorodichloride is shown in Table I. The yield given for each product is the maximum obtained when the reaction was adjusted for the preparation... 

From these experiments it is clear that, in the reaction of a poly-chloroparaffin with antimony trifluoride activated by a pentavalent antimony salt ... 

Preparation of Antimony Trifluorodichloride (SbF3Cl2). This is made in the steel reaction vessel, described on p. 59. A known quantity of antimony fluoride is placed in the vessel the vessel is evacuated, the needle valve is closed, and the whole is weighed. Connection is established to a chlorine cylinder, and the needle valve is opened to permit qhlorine to fill the vessel. Part of it is absorbed rapidly by the salt, with evolution of heat. Soon the reaction slows down as indicated by the rate of pressure fall when the needle valve is dosed. Weighing indicates the amount of chlorine present in the vessel. When the absorption practically ceases, the valve is closed, and the connection with the chlorine tank is removed. The reaction vessel is alternately heated gently, then allowed to cool in order to permit SbFsCl2, which is a viscous liquid, to flow and expose fresh surfaces of crystalline antimony trifluoride. The operation is ended after the absorption of the desired quantity of chlorine. 

Hexachloro-l,3-difluoropropane (CCI2FCCI2CCI2F). 0 In a round-bottomed flask equipped with an air-cooled reflux condenser a mixture of 1500 g. of octachloropropane, 560 g. of antimony, trifluoride, and 75 g. of antimony pentachloride is heated for five hours on a steam bath. A further quantity of 100 g. of antimony pentachloride is then added in small portions, and the heating is continued for twenty hours. The reaction mixture, which gradually becomes homogeneous, is allowed to cool before it is poured into aqueous acid, then is washed and dried. The crude product amounts to 1092 g., from which about 750 g. of difluoride is obtained by fractional distillation at 90 mm. The boiling. point at 760 mm. is 194°, and the freezing point is 29.8°. 

Dichlorodifluoromethane and Trichlorofluoromethane.60 In a flask connected to an ice-cooled reflux condenser, a mixture of 2 moles of carbon tetrachloride and 1 mole of antimony trifluoride is cooled to 0°. After addition of 0.1 mole of antimony pentachloride, the mixture is allowed to warm until the reaction starts. The reaction is regulated by intermittent cooling and heating in order not to overtax the reflux condenser. The uncondensed vapors are led to a receiver cooled with solid carbon dioxide. The distillate is a mixture of CCl3F(b.p. 25°) and CCl2F2(b.p. —30°) whose composition depends on the efficiency of the dephlegmation but is usually 50-50 in a laboratory operation. At the... 

The only fluoropentaborane known is the 2-substituted derivative which was obtained by the reaction of 2-IB5H8 with antimony trifluoride in a flow system at low pressure 184). The compound is a liquid which is moderately stable at room temperature. No boron-fluorine spin coupling is evident in the boron-11 nmr spectrum, but a poorly resolved quartet (Jpb = 60 hz) is observed in the fluorine-19 nmr spectrum. The analogous reaction of I-IB5H8 with antimony trichloride gave a product which was too unstable to characterize 184>. 

Xenon difluoride reacts also with some halosubstituted alkanes18,19 at room temperature in chloroform, carbon tetrachloride, dichloromethane or bromoform, and depending on the nature of the solvent used chloro or bromo derivatives are isolated with imidazo-(l,2-fr)-pyridazine18. Carbon tetrachloride reacts with xenon difluoride at 180°C, while room-temperature transformations are achieved when various catalysts [antimony trifluoride, tantalum(V) fluoride or silica dioxide] are used, whose structure also influences the product distribution20. Tris(fluorosulfonyl)methane gives a fluoro-substi-tuted product in its reaction with xenon difluoride in difluorodichloromethane21. 

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