Mechanism of Photo-Oxidation
of Heptafluorobutyric
Anhydride in the Presence of NO2. Synthesis
and Characterization of Heptafluoropropyl Peroxynitrate, CF3CF2CF2OONO2
posted on 2012-10-11, 00:00authored byAdriana
G. Bossolasco, Fabio E. Malanca, Maxi A. Burgos Paci, Gustavo
A. Argüello
The photolysis of heptafluorobutyric anhydride at 254
nm in the
presence of NO2 and O2 has been studied. It
leads to the formation of CF3CF2CF2OONO2, CF3CF2OONO2, and
CF2O as the only fluorine-containing carbonaceous products.
The formation of the new heptafluoropropyl peroxynitrate (HFPN, CF3CF2CF2OONO2), as one of the
main products, is a consequence of the formation of CF3CF2CF2OO• radicals followed
by the reaction with NO2. To characterize HFPN, the UV
absorption cross sections and their temperature dependence between
245 and 300 K have been measured over the wavelength range 200–300
nm as well as the infrared absorption cross sections. Kinetic parameters
for its thermal decomposition are also presented in the temperature
range between 281 and 300 K. The Rice–Ramsperger–Kassel–Marcus
calculation reveals that the rate coefficient for the thermal decomposition
at 285 K is almost independent of total pressure. The mechanism for
the decomposition of CF3CF2CF2OONO2 in the presence of NO was adjusted by a kinetic model, which
enabled the calculation of important rate coefficients.