Thermal decomposition of trifluoromethoxycarbonyl peroxy nitrate, CF₃OC(O)O₂NO₂

Abstract

The thermal decomposition of trifluoromethoxycarbonyl peroxy nitrate, CF3OC(O)O2NO2, has been studied between 278 and 306 K at 270 mbar total pressure using He as a diluent gas. The pressure dependence of the reaction was also studied at 292 K between 1.2 and 270 mbar total pressure. The rate constant reaches its high‐pressure limit at 70 mbar. The first step of the decomposition leads to CF3OC(O)O2 and NO2 formation, that is, CF3OC(O)O2NO2 + M ⇆ CF3OC(O)O2 + NO2 + M (k1, k−1). Reaction (−1) was prevented by adding an excess of NO that reacts with the peroxy radical intermediate and leads to carbonyl fluoride (CF2O), carbon dioxide (CO2), nitrogen dioxide (NO2), and small quantities of CF3OC(O)O2C(O)OCF3. The kinetics of reaction (1) was determined by following the loss of CF3OC(O)O2NO2 via IR spectroscopy. The temperature dependence of the decomposition follows the equation k1(T) = 1.0 × 1016 e−((111±3)/(RT)) for the exponential term expressed in kJ mol−1. The values obtained for the kinetic parameters such as k1 at 298 K, the activation energy (Ea), and the preexponential factor (A) are compared with literature data for other acyl peroxy nitrates. The atmospheric thermal stability of CF3OC(O)O2NO2 and its dependence with altitude is discussed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 831–838, 2008

Trifluoromethyl Fluoroformyl Trioxicarbonate, CF3OC(O)OOOC(O)F: The First Nonsymmetric Acyl Trioxide

“…20 On the other hand, if decomposition followed path 2, FC(O)OONO 2 would be formed 21 with a rate constant k 26 ) 5.5 × 10 -12 cm 3 molecules -1 s -1 . 22 The statement that CF Since the two possible peroxynitrates that should form from the actual sample have been independently characterized 4,19,21,24 and as they are the only peroxy species formed, their quantification as the main products in the thermal decomposition of the trioxide is conclusive proof of the identity of trifluoromethyl fluoroformyl trioxicarbonate. The products obtained and the sum of the absolute quantities of FC(O)OONO energy differences with regard to the conformers analyzed.…”

“…Nevertheless, we first had to study the decomposition of pure CF 3 OC(O)OOOC(O)OCF 3 in excess of NO 2 to be able to subtract its contribution when dealing with the purest synthesized sample of CF 3 OC(O)OOOC(O)F (see Experimental Section). The decomposition of CF 3 OC(O)OOOC(O)OCF 3 following reaction 1 gives rise, in the presence of NO 2 , to trifluoromethoxy carbonyl peroxynitrate 19 The reaction proceeds with a rate constant k 25 ) 6.6 × 10 -12 cm 3 molecules -1 s -1 . 20 On the other hand, if decomposition followed path 2, FC(O)OONO 2 would be formed 21 with a rate constant k 26 ) 5.5 × 10 -12 cm 3 molecules -1 s -1 .…”

Thermal Decomposition of CxF2x+1C(O)OONO2 (x = 2, 3, 4)

“…Our laboratory has synthesized and characterized many peroxyacyl nitrates. [3][4][5][6][7][8][9][10][11][12][13] In the present article, the focus of the study is set on the thermal stability of the C x F 2x+1 C(O)OONO 2 family (x = 2, 3, 4), formed from the atmospheric degradation of molecules containing the C x F 2x+1 C(O) moiety. These include for example the perfluoroaldehydes, C x F 2x+1 C(O)H, which are formed in the atmospheric degradation of telomeric alcohols, C x F 2x+1 CH 2 CH 2 OH (x = 2, 4).…”

“…They are a reservoir of nitrogen dioxide and peroxy radicals. , In the atmosphere, PANs can be transported from polluted sites to higher altitudes in the troposphere and the tropopause, where the lower temperatures increase their stability, and finally reach remote sites, polluting remote locations. Our laboratory has synthesized and characterized many peroxyacyl nitrates. − …”

Photolysis of n-Propyl Formate in the Presence of O2 and NO2: Peroxy Formyl Propyl Nitrate CH3CH2CH2OC(O)OONO2 Synthesis and Characterization

“…Many studies have concluded that the oxidation of either hydrogenated or fluorinated compounds in the presence of NO 2 leads to the formation of peroxynitrates (ROONO 2 ), important reservoir species in the atmosphere. − In particular, the photo-oxidation of formates in the presence of NO 2 should lead to the formation of an important family of thermally stable peroxy acyl nitrates, C x H 2 x +1 OC­(O)­OONO 2 , of which only the shorter chain ( x = 1, 2) congeners have been reported. , …”