16282-67-0Relevant articles and documents
Reaction between carbon dioxide and elementary fluorine
Hasegawa, Yasuo,Otani, Reiko,Yonezawa, Susumu,Takashima, Masayuki
, p. 17 - 28 (2007)
Reactions between carbon dioxide and fluorine were examined at temperatures of 303-523 K under various pressure and mixture ratios of both gases. Reactions were carried out similarly under the existence of NaF, CsF and EuF3. After the reaction, fluorine was removed and the reaction products were analyzed using FT-IR, GC/FT-IR and GC/MS. The major products were CF3OF, COF2, CF4 and CF2(OF)2. The best yield of COF2 was 11.1% under the reaction condition of CO2/F2 = 76 kPa/76 kPa with temperature of 498 K for 72 h in a direct reaction. The formation rate of COF2 in the direct reaction was estimated as 0.232 dm3 mol-1 h-1 under the reaction conditions of CO2/F2 = 76 kPa/76 kPa, at 498 K. In the presence of CsF, it was estimated as 1.88 dm3 mol-1 h-1 at CO2/F2 = 76 kPa/76 kPa at 498 K. The activation energy of the COF2 formation in the direct reaction was estimated as 45.7 kJ mol-1 at CO2/F2 = 76 kPa/76 kPa at 498 K. In addition, 24.2 and 38.9 kJ mol-1 were evaluated at CO2/F2 = 76 kPa/76 kPa at 498 K, respectively, in the presence of CsF and EuF3.
Facile, Temperature-Dependent Formation of Gaseous C1 and C2 Perfluoroalkyl Hypofluorites. Applications as Electrophilic Fluorinating Agents.
Mulholland, G. Keith,Ehrenkaufer, Richard E.
, p. 1482 - 1489 (2007/10/02)
A convenient method for continuous-flow production of gaseous C1 and C2 fluoroxyperfluoroalkanes (RfOF) was developed.Passage of 10percent F2 through short columns of CF3CO2Na resulted in the formation of the following hypofluorites: CF3CF2OF, CF3OF, CF3CF(OF)2, and CF2(OF)2.No other significant oxidizing side products or residual F2 were present in the column effluent under normal conditions.Identifications of the hypofluorites were made through direct 19F NMR measurements at -40 deg C of the -196 deg C condensate of the column effluent and also on the basis of stilbene trapping experiments.Hypofluorites were formed rapidly at temperatures at least as low as -110 deg C but no reaction occurred at -160 deg C.The ratios of hypofluorites formed strongly depended on the temperature of the salt column.Yields of CF3CF(OF)2 exceeding 90percent, based on input F2, were obtained at salt temperatures between -110 and -78 deg C.At moderate temperatures (-20 to +20 deg C) CF3CF2OF was the predominant products, accompanied by significant amounts of CF3OF and CF3CF(OF)2 and traces of CF2(OF)2.CF3OF was the major hypofluorite formed at high (60 to 100 deg C) temperatures.No hypofluorites were detected when the column temperature was above 135 deg C.A minimum of specialized equipment is required to produce hypofluorites by this method.It makes expensive or previously exotic, little-studied fluoroxy compounds readily available for synthetic applications.Fluorinations of anisole, 3,4,6-triacetyl-D-glucal, phenylmercuric acetate, and N,N-dimethylphenylacetamide tert-butyldimethylsilyl enolate were carried out to demonstrate the synthetic utility of RfOF and to compare its chemical reactivity with acetyl hypofluorite, an electrophilic fluorinating agent currently in wide use.RfOF, used as a homogeneous reagent, was comparable in fluorinating ability but was less regio- and stereoselective than acetyl hypofluorite in the cases examined.
