Carbon monoxide carbonyl difluoride

Trifluoromethyl hypofluorite was first made by Cady by passing methanol [184] or carbon monoxide [185, 186] with fluorine over silver difluoride at elevated temperatures. Later, trifluoromethyl hypofluorite and higher perfluoroalkyl hypofluorites were prepared by treating the appropriate carbonyl compound with fluorine in the presence of dry caesium fluoride at sub-zero temperatures (Fig. 81) [187-189]. 

The first authentic preparation of carbonyl difluoride in a pure state (c/. Section 13.7.5.4) was described by Ruff and Miltschitsky in 1934, by the interaction of carbon monoxide and silver(II) fluoride [1756]. Although this method still constitutes a convenient... 

Carbonyl difluoride can be synthesised by burning carbon monoxide in an atmosphere of difluorine according to [1193] ... 

When carbon monoxide is swept over powdered [Oj][SbFg] at ambient temperature, a rapid and exothermic reaction takes place producing dioxygen and carbonyl difluoride according to [1944] ... 

Carbonyl difluoride will react with partially oxidized charcoals to produce graphite fluorides, containing up to 10% fluoride [ICI29]. Treatment of carbonyl difluoride with carbon monoxide at temperatures in excess of 350 C and elevated pressures, and in the presence of a catalyst e.g. Fe or CuFj), is reported to generate tetrafluoroethene [842] ... 

The reaction takes place in a rotating autoclave over eight hours, and under a partial pressure of carbon monoxide of 12 MPa. After bleeding off the carbonyl difluoride co-product and the excess of carbon monoxide, the COFI was removed by distillation at about 26.7 kPa, foliowed by a further distillation in vacuo over antimony powder to give a yield of 12% for COFI (based on IF ). The material is suitably stored in quartz vessels cooled with dry ice [1196,1751]. 

Studies on the well known reaction between fluorine and carbon monoxide have revealed that a film of silver fluoride(s) on copper truly is a catalyst for the reaction Fj + CO - COFa, and for subsequent changes producing bistrifluoromethyl peroxide and trifluoromethyl hypofluorite, whereas caesium fluoride is not and since neither copper nor silver iluoride(s) appears to be a good catalyst for the reaction CF3 OF + COFj CFa O O CFg, it has been suggested that the fluorination of carbon monoxide or carbonyl fluoride in the presence of silver difluoride may possibly involve the steps... 

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