Group 1 fluorides carbonyl difluoride

An example of cleavage ol the sulfur-oxygen bond in trifluoromethane-sulfonic ester has been reported Tnfluororaethyl triflate reacts with neutral or anionic nucleophiles with elimination of carbonyl difluoride and formation of trifluoromethanesulfonyl fluoride [57] (equation 32) The mechanism of this reaction involves elimination of fluoride ion, which is a chain carrier in the substitution of fluorine for the trifluoromethoxy group... 

Fluorine and trifluoromethyl groups appear to stabilize oxygen catenation. The trioxide can be approached alternatively by the reaction of oxygen difluoride and carbonyl difluoride over a metal fluoride catalyst. Depending on conditions, the trioxide will be the major product (equations 56 and 57). 

Group 1 metal fluorides have been employed as column packings for the determination of COF2 (and other fluorocarbonyl compounds) in mixtures with tetrafluoroethene [967]. By using a column composed of CsF supported upon CaFj, the tetrafluoroethene is not chemisorbed and is eluted rapidly. The fluorocarbonyl compounds (CF3)jC=0 (b.pt. -28 C), CF3C(0)F (b.pt. -59 C), and COF (b.pt. -84.6 C), however, are eluted in reverse order of boiling temperatures, so that carbonyl difluoride is eluted last [967]. The chemisorption arises from the reversible chemical process [1692] ... 

A higher (62%) yield of benzoyl fluoride was obtained from the reaction of benzoic acid and COFj in the presence of sodium fluoride, by beating the charged vessel at 175 "C for 10 h. The presence of the highly electronegative fluorine atom in benzoyl fluoride clearly deactivates the carbonyl group for further reaction with carbonyl difluoride. 

SF4 forms adducts with main group inorganic fluorides, and these have been variously described as simple Lewis acid-base systems (with SF4 behaving as the base) or as ionic systems such as [SFsJ [BF4] . The reactions of SF4 with organic molecules have been widely studied. The most important reaction is the conversion of a carbonyl group to a difluoride (equation 51). 

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