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

✍ Scribed by Martín D. Manetti; Fabio E. Malanca; Gustavo A. Argüello

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 185 KB
• Volume: 40
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20355

✦ Synopsis

Abstract

The thermal decomposition of trifluoromethoxycarbonyl peroxy nitrate, CF~3~OC(O)O~2~NO~2~, 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 CF~3~OC(O)O~2~ and NO~2~ formation, that is, CF~3~OC(O)O~2~NO~2~ + M ⇆ CF~3~OC(O)O~2~ + NO~2~ + M (k~1~, k~−1~). Reaction (−1) was prevented by adding an excess of NO that reacts with the peroxy radical intermediate and leads to carbonyl fluoride (CF~2~O), carbon dioxide (CO~2~), nitrogen dioxide (NO~2~), and small quantities of CF~3~OC(O)O~2~C(O)OCF~3~. The kinetics of reaction (1) was determined by following the loss of CF~3~OC(O)O~2~NO~2~ via IR spectroscopy. The temperature dependence of the decomposition follows the equation k~1~(T) = 1.0 × 10^16^ e^−((111±3)/(RT))^ for the exponential term expressed in kJ mol^−1^. The values obtained for the kinetic parameters such as k~1~ at 298 K, the activation energy (E~a~), and the preexponential factor (A) are compared with literature data for other acyl peroxy nitrates. The atmospheric thermal stability of CF~3~OC(O)O~2~NO~2~ and its dependence with altitude is discussed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 831–838, 2008