Trifluoride with Chlorine

Submitted by CARL J. SCHACK and R. D. WILSON Checked by DARRYL D. DESMARTEAUt 

---

Trifluoromethylsulphur chloride tetrafluoride, CF3-SF4C1 (which possesses a tronj-octahedral configuration so that all four fluorines attached to sulphur are equivalent), has been prepared by reaction of trifluoromethylsulphur trifluoride with chlorine in the presence of caesium fluoride at room temperature this synthesis is analogous to that of sulphur chloride pentafluoride from sulphur tetrafluoride, chlorine, and caesium fluoride, a method claimed to be inferior to the addition of chlorine monofluoride to sulphur tetrafluoride in the presence of caesium fluoride specially activated by a fusion-solidification-fine-grinding technique. Bis(perfluoroalkyl)-sulphur difluorides result from the fluorination of bis(perfluoroalkyl) sulphides with chlorine monofluoride ... 

Compounds containing fluorine and chlorine are also donors to BF3. Aqueous fluoroboric acid and the tetrafluoroborates of metals, nonmetals, and organic radicals represent a large class of compounds in which the fluoride ion is coordinating with trifluoroborane. Representative examples of these compounds are given in Table 5. Coordination compounds of boron trifluoride with the chlorides of sodium, aluminum, iron, copper, 2inc, tin, and lead have been indicated (53) they are probably chlorotrifluoroborates. 

Treatment of coal with chlorine or bromine results in addition and substitution reactions. At temperatures up to 600°C chlorinolysis produces carbon tetrachloride, phosgene, and thionyl chloride (73). Treatment with fluorine or chlorine trifluoride at atmospheric pressure and 300°C can produce large yields of Hquid products. 

Similar preference in replacement by fluorine of tertiary versus secondary and secondary versus primary hydrogens is observed in the fluorination of alkanes with chlorine trifluoride in 1,2-difluorotetrachloroethane at room temperature (Table 3). Skeletal rearrangements accompany the fluorination [31]... 

Table 3. Fluorination of Mkanes with Chlorine Trifluoride ]...

In the preparation of trifluoromethylsulfur trifluoride, the chloride must be dissolved in a fully halogenated solvent to prevent explosion during treatment with chlorine fluoride or chlorine trifluoride. 

Studies of the interaction of chlorine trifluoride with deuterium or hydrogen atoms in a scattering chamber were accompanied by frequent flashes or explosions, within 3 h if the reactor had been vented, or after 8 h if it had not. 

Combinations of liquid chlorine trifluoride with several halocarbons except perfluo-rohexane exploded immediately when suddenly mixed at all temperatures between 25° and — 70°C. Poly(chlorotrifluoroethylene), below See Carbon tetrachloride, Fluorinated solvents, both above... 

The explosive interaction of chlorine trifluoride with methane and its homologues... 

An old method of producing anhydrous tribromides and triiodides involves heating the anhydrous trichloride in a stream of HBr or HI at 400-600°C for 7-10 hours. For the triiodides (39), a mixture of H2/HI is normally used, and the conversion takes longer than for the tribromides. This process is difficult to carry out, as the last traces of chloride are very difficult to remove. Recently trifluorides LnF3 (Ln = Ce, Nd, Y) have been treated with chlorine to produce trichlorides (114). 

Reaction with iodine forms iodine monochloride, ICl which combines with excess SbCls to form adducts, SbCR 2IC1 and SbCls 31 Cl similarly reaction with chlorine trifluoride, CIF3 gives antimony dichlorotrifluoride, SbCbFs. 

Heating with chlorine, or passing the gas into the molten trichloride yields antimony pentachloride, SbCls. Reaction with HF produces trifluoride, SbF3. 

Arsenic trifluoride is hydrolyzed by water. It reacts with chlorine gas at ice-cold temperature to form arsenic dichloride trifluoride, AsCbFs, a solid hygroscopic product that consists of the ions AsCh and AsFe. 

Fluorine also reacts with other halogens, forming interhalogen compounds. While with bromine and iodine it reacts vigorously at ordinary temperatures, with chlorine the reaction occurs at 200°C. Such interhalogen products with these halogens include iodine heptafluoride, bromine trifluoride, bromine pentafluoride, and chlorine trifluoride. Metalloid elements, such as arsenic, silicon, selenium, and boron also inflame in a stream of fluorine, forming fluorides. 

The metal combines with halogens at elevated temperatures. When heated with fluorine at 500 to 600°C, it forms a trifluoride, RhFs, a red rhombohedral crystalline powder insoluble in water, dilute acids, or alkalis. Also, a blue tetrafluoride, RhF4, is formed as a minor product. When heated with chlorine gas above 250°C, the brown-red trichloride, RhCls, forms. It is hygroscopic, decomposing at 450°C. 

When treated with chlorine trifluoridc in CFC-12 at — 78 C, trifluoromethanesulfenyl chloride and bis(lrifluoromethyl) disulfide are transformed into trifluoromethylsulfur trifluoride (95%) and bis(trifluoromethyl)sulfur difluoride (90%). respectively.121... 

The preparation of selenium tetrafluoride in normal glass apparatus has been reported by the reaction of selenium metal with chlorine trifluoride and selenium tetrafluoride as the solvent.81 Caution chlorine trifluoride (C1F3) is extremely reactive and must be handled with care, avoiding organic compounds and moisture. 

Difluoro-l-silacyclobutane is obtained by the exchange of two chlorine atoms for fluorine in the 1,1-diehloro analog using antimony(III) fluoride in w-xylene yield 46% bp 36 -38 C.64 Antimony(lll) fluoride is supposed to interact, through its lone electron pair, with coordinative-ly unsaturated silicon rather than with chlorine atoms at silicon. Because of this Si —Cl compounds are fluorinated slower than C — Cl derivatives in the presence of boron trifluoride.65... 

Tellurium hexafluoride itself has been found to form complexes with potassium, rubidium and cesium fluorides. The cesium compound has a stochiometry approaching Cs2TeF8 and, in these types of complexes, the stability of the lattice appears to be inversely related to the polarizing power of the cation and the compounds are only stable in the solid state.41 Several heptafluorotellurates(VI) have been prepared from the reaction of tellurium with chlorine trifluoride in anhydrous hydrofluoric acid followed by addition of the metal fluoride.42... 

The trichloride reacts violently with fluorine to form the trifluoride.4 Chlorine dissolves readily at low temperatures without reaction (see p. 110), the gas being expelled on warming.5 Iodine also dissolves without reaction,6 the solubility increasing with temperature, thus ... 

CondChemDict(l96l), 255 13)North American Aviation Inc, Rocketdyne Div Rpt R-3136, "Chlorine Trifluoride Handling Manual (Sept. 1961) 14)H.Allen, Jr M.L. Pinns, "Relative Ignitability of Typical Solid Propellants with Chlorine Trifluoride , NASA Tech Note D-1533(Jan 1963)... 

The UFg used in producing nuclear fuels is prepared by reaction of uranium metal with chlorine trifluoride. Tell which atoms have been oxidized and which reduced, and balance the equation. 

---