L.P. Breitenbach

Fourier transform IR spectroscopic observation of pernitric acid formed via HOO + NO2 → HOONO2

Abstract Kinetic and spectroscopic evidence has been found for the formation of pernitric acid via HOO + NO2 → HOONO2 using Cl-atom sensitized oxidation of H2  NO2 mixture and a Fourier transform IR spectroscopic detection method.

An FTIR study of mechanisms for the HO radical initiated oxidation of C2H4 in the presence of NO: detection of glycolaldehyde

Using the long-path FTIR method, glycolaldehyde, CH2(OH)CHO, was detected among the products in photolysis of mixtures containing C2H4, NO and RONO (R = alkyl group) at ppm concentrations in air. The results suggest the occurrence of both unimolecular dissociation and O2 reaction of an oxy-radical, CH2(OH)CH2O, formed in the HO-initiated oxidation of C2H4 in the presence of NO.

Fourier transform IR spectroscopic observation of propylene ozonide in the gas phase reaction of ozone—cis-2-butene—formaldehyde

Abstract IR spectroscopic evidence has been found for the gas phase formation of propylene ozonide via the homogeneous bimolecular reaction of the cis-2-butene ozonolysis intermediate with formaldehyde.

An FIIR study of the mechanism for the gas phase reaction between HO2 radicals

Abstract Product studies of the self-reaction of HO2 were made using the FTIR method in the photolysis of Cl2 in the presence of H2 and O2 at 700 Torr total pressure and 298 K. The nature of the transition state involved in the formation of H2O2 via an H2O4 adduct was determined by an 18O-labeling technique, i.e. H16O2 + H18O2 → H216O2 + 18O2 and H218O2 + 16O2 but not H216O18O + 16O18O. An alternative reaction path 2HO2 → O3 + H2O was determined to be less than 0.1% of the total reaction of HO2.

FTIR studies of the kinetics and mechanism for the reaction of Cl atom with formaldehyde

Abstract Product studies were made with the FTIR method in the photolysis of mixtures containing Cl 2 and CH 2 O up to 1 torr each in I atm Ar. The formation of two principal products, HCl and HCClO, can be accounted for by the chain photochlorination of CH 2 O i.e., Cl 2 + hv → 2 Cl, Cl + CH 2 O → CHO + HCl, CHO + Cl 2 → HCClO + Cl. The rate constant for the ClCH 2 O reaction was determined from relative decay rates of CH 2 O and C 2 H 6 in the photolysis of Cl 2 CH 2 OC 2 H 6 mixtures. The value of k (Cl + CH 2 O/Cl + C 2 H 6 ) = 1.3 combined with the literature value of k (Cl + C 2 H 6 = 6 × 10 −11 cm 3 molecule −1 s −1 gives k (Cl + CH 2 O) = 7.8 × 10 −11 cm 3 molecule −1 s −1 at 298 ± 2 K.

FTIR spectroscopic observation of peroxyalkyl nitrates formed via ROO + NO2 → ROONO2

Abstract Kinetic and spectroscopic evidence has been obtained for the formation of peroxyalkyl nitrates via ROO + NO 2 → ROONO 2 (R = C n H 2 n +1 , n = 1–6) using CI-atom sensitized oxidation of alkane-NO 2 mixtures and a long path Fourier transform IR spectroscopic detection method.

Further IR spectroscopic evidence for the formation of CH2(OH)OOH in the gas-phase reaction of HO2 with CH2O

Abstract Two O-H stretch bands at 3647.5 and 3598.3 cm−1 have been observed for the previously reported “metastable species” formed by HO2-CH2O interactions. These bands are consistent with the presence of an OH and an OOH group and provide support for the earlier tentative identification of hydroperoxy-hydroxy-methane, CH2(OH)OOH, formed via CH2O + HO2 → CH2(OH)OO, CH2(OH)OO + HO2 → CH2(OH)OOH + O2. This compound is relatively stable in the dark at 25°C.

Fourier transform IR spectroscopic observation of chlorine nitrite, ciono, formed via Cl + NO2 (+M) → ClONO(+M)

Abstract Using the FTIR method, chlorine nitrite (ClONO) and nitryl chloride (ClNO 2 ) were identified as reaction products in the photolysis of Cl 2 -NO 2 mixtures. The observed yields of ClONO (⩾ 80%) and ClNO 2 (⩽ 20%) suggest that Cl atom adds mainly to the O atom rather than the N atom of NO 2 molecule.

FTIR studies of the Cl-atom initiated oxidation of formaldehyde: detection of a new metastable species in the presence of NO2

Fourier transform infrared studies of the photolysis of mixtures containing Cl2 (≈1 Torr), CH2O (≈1 Torr) and air (700 Torr) at 25°C have provided further evidence for the previously proposed HO2-radical chain mechanism for the formation of HCOOH from CH2O. In the presence of added NO2, a new transient “peroxynitrate-type” product was observed and identified tentatively as hydroxy-methylperoxy nitrate, CH2(OH)OONO2, formed via HO2 + CH2O→ (HO2CH2O)→ CH2(OH)OO and CH2(OH)OO + NO2→ CH2(OH)OONO2.

FTIR spectroscopic observation of haloalkyl peroxynitrates formed via ROO + NO2 → ROONO2 (R CCI3, CFCI2 and CF2CI)

Kinetic and spectroscopic evidence has been obtained for the formation of haloalkyl peroxynitrates via the gas phase reactions ROO + NO2(+ M) → ROONO2(+M) (R  CCI3, CFCI2 and CF2CI). The possibility is raised that these reactions may participate in stratospheric chemistry.