Me. Jenkin et al., MECHANISMS OF THE CL-ATOM-INITIATED OXIDATION OF ACETONE AND HYDROXYACETONE IN AIR, Journal of the Chemical Society. Faraday transactions, 89(16), 1993, pp. 2983-2991
Citations number
41
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
The products of the Cl-atom-initiated oxidation of acetone and hydroxy
acetone (CH3COCH2OH) in O2-N2 MiXtures at 700 Torr and 298 K have been
identified using long-path-length FTIR spectroscopy and long-path-len
gth UV-visible diode array spectroscopy. The oxidation of acetone yiel
ds methyl glyoxal (CH3COCHO), HCHO, CO, CO2, CH3COOH, CH3OH, HCOOH and
O3 as identifiable products. The data have been analysed, utilising t
he results of a kinetic study of the oxidation of acetone in air. The
mechanism of the oxidation proceeds initially via the production of ac
etonylperoxy radicals (CH3COCH2O2) which are removed by their self-rea
ction (3), and reaction with other peroxy radicals [CH3C(O)O2, CH3O2 a
nd HO2] produced by the subsequent chemistry: 2CH3COCH2O2 --> 2CH3COCH
2O + O2 (3a) --> CH3COCHO + CH3COCH2OH + O2 (3b) The thermal decomposi
tion of CH3COCH2O radicals produced in channel (3a) into CH3CO radical
s and HCHO, is shown to predominate over the alternative reaction with
O2, under the conditions of these experiments: CH3COCH2O + M --> CH3C
O + HCHO + M (12) CH3COCH2O + O2 --> CH3COCHO + HO2 (13) Measurements
of the yields of HCHO and CH3COCHO are consistent with the operation o
f both channels of reaction (3) and allow certain conclusions to be dr
awn concerning the reactions of CH3COCH2O2 with CH3O2 and CH3C(O)O2. T
he only detected primary organic product of the oxidation of CH3COCH2O
H is CH3COCHO, formed with a yield of (100 +/- 5)% by the following re
action sequence: Cl + CH3COCH2OH --> HCl + CH3COCHOH (4) CH3COCHOH + O
2 --> CH3COCHO + HO2 (5) The concentration-time dependence of a range
of secondary organic products, formed in the system was also measured.
Identifiable products are CO, CO2, CH3COOH, HCHO, CH3OH, HCOOH and py
ruvic acid (CH3COCOOH). These results are consistent with the presence
of the CH3COCH(OH)O2 radical, formed as an intermediate in reaction (
5): CH3COCH(OH)O2 <-- --> CH3COCHO + HO2 (5'')