Primary quantum yields of photodecomposition of acetone in air under tropospheric conditions

Gas phase reactions of alkyl nitrates with hydroxyl radicals under tropospheric conditions in comparison with photolysis

“…The photolysis of acetone was used as reference to compare the results of the laboratory experiments with the photodissociation of the nitrates in the troposphere, since both substances absorb UV light in the same spectral region between 290 and 330 nm (Calvert and Pitts, 1966;Csizmadia et al, 1973) and the photolysis frequency of acetone can be calculated for the troposphere. The photolysis frequency of acetone was determined in the laboratory from independent experiments where only acetone diluted in air was irradiated in the reactor by using the known quantum yield of CO production, 0¢o =0.024 (Gardner et al, 1984).…”

“…For acetone, a value of J= 3.8 × 10 -7 s -I has been derived by using the solar flux intensities reported by Finlayson-Pitts and Pitts (1986) (with reference to the results of Peterson (1976) andDemerjian et al (1980)), the absorption spectrum given by Calvert and Pitts (1966), and the quantum yield of photodissociation, 0 = 0.08, from Gardner et al (1984). The experimental results and the estimated photolysis frequency for isopropyl nitrate are listed in Table VI1.…”

Kinetics of the reactions of hydroxyl radicals with alkyl nitrates and with some oxygen-containing organic compounds studied under simulated atmospheric conditions

“…45 days. Gardner et al, (1984) reported a photo-dissociative lifetime of ca. 14 days for a solar zenith angle of 40 °, so, although photolysis is slow, it will be the major reaction channel for acetone in the polluted troposphere.…”

The production of carbon monoxide by the homogeneous NO x -induced photooxidation of volatile organic compounds in the troposphere

“…The quantum yields for photodissociation of 2-propanone at 299 and 313 nm have been reported to be independent of pressure between 1000 and 500 mbar and increase by approximately 25% between 1000 and 250 mbar (Gardner et al, 1984). The quantum yields also do not vary with temperature between 298 and 273 K (Gardner et aL, 1984).…”

“…Photodecomposition rates in air for a number of aldehydes and ketones are calculated from the actinic fluxes within the planetary boundary layer (Dimerjian et al, 1980), along with absorption cross-sections and quantum yields, ~z (F6rgeteg et al, 1979;Horowitz and Calvert, 1982;Gardner et aL, 1984;Desai et aL, 1989;Heicklen et al, 1986;Meyrahn et al;Atkinson et al, 1986), or from photolysis rates relative to NO 2 (Plum et aL, 1983). For CH3COC2Hs, a 9~a of 0.1 is assumed (Carter et al, 1986), and for C2HsCOC2H 5 and (CH3)2CHCOCH 3, a #z of 0.2 is assumed within the range of 295 um to 340 nm.…”