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

Abstract

The photo-oxidation of n-propyl formate (initiated by chlorine atoms) was studied in the presence of NO2, and the products were identified. The Cl atom attack to the molecule occurs in four sites, leading to the formation of formic acid, carbon dioxide, dicarbonylic products, nitrates, peroxy propionyl nitrate (CH3CH2C(O)OONO2, PPN), and a new peroxynitrate, peroxy formyl propyl nitrate (CH3CH2CH2OC(O)OONO2, PFPN). To characterize bulk quantities of the PFPN, its synthesis was carried out by the photolysis of mixtures of CH3CH2CH2OC(O)H, NO2, Cl2, and O2. After purification, its infrared spectrum and thermal stability were determined. The main infrared absorption bands and their corresponding cross sections are 796, 1219, 1302, 1741, and 1831 cm(-1) (1.16, 3.11, 0.88, 2.42, and 1.34 × 10(-18) cm(2) molec(-1), respectively). Thermal decomposition was studied as a function of pressure from 6.0 to 1000 mbar at 298 K, and the activation energy was determined between 293 and 304 K at total pressures of 9.0 and 1000 mbar (Ea = 98 ± 3 and 110 ± 2 kJ/mol, respectively). The atmospheric thermal lifetimes were obtained from kinetic parameters.

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. − …”