Hydroxyl-radical-initiated oxidation of isobutyl isopropyl ether under laboratory conditions related to the troposphere Product studies and proposed mechanism

Kinetics of OH and Cl reactions with a series of aldehydes

“…, at 298 K, the value reported by Kerr and Sheppard[5], Semmes et al[8], and Stemmler et al[9] is around 2.6 ϫ 10 Ϫ11 cm 3 molecule Ϫ1 s Ϫ1 , while that from Audley et al is lower (1.74 ϫ 10 Ϫ11 cm 3 molecule Ϫ1 s Ϫ1 )[6] and that from Dobé et al is almost a factor 2 higher (4.47 ϫ 10 Ϫ11 cm 3 molecule Ϫ1 s Ϫ1 )[10]. Our value (2.6 ϫ 10 Ϫ11 cm 3 molecule Ϫ1 s Ϫ1 ) is in very good agreement with the first ones.…”

Reactions of OH and Cl with isopropyl formate, isobutyl formate, n-propyl isobutyrate and isopropyl isobutyrate

“…The other processes such as reactions with O 3 , NO 3 and photolysis are expected to be negligible. Tropospheric removal by uptake in surface and rainwater or cloud droplets are also of negligible importance as sinks for these compounds since they are volatile and sparingly soluble in water.…”

“…The only available data are those for OH reaction with isopropyl formate from Stemmler et al [3] (k = (2.2 ± 0.2) Â 10 À12 , placed on absolute basis using k(n-C 3 H 7 ) 2 O = 2.0x10 À11 [2]), Szilagyi et al [4] (k = (1.87 ± 0.08)x10 À12 , using flow discharge flow tube-resonance fluorescence technique) and Pimentel et al [5] (k = (2.37 ± 0.40)x10 À12 , placed on absolute basis using k(C 2 H 4 ) = 7.9 Â 10 À12 [10]. Pimentel et al have also reported the rate coefficient for the reaction of OH isopropyl isobutyrate (k = (7.0 ± 0.4)Â10 À12 placed on absolute basis using k(n-C 3 H 7 ) 2 O = 2.0 Â 10 À11 taken from Calvert et al [2]).…”

“…The reaction of OH with isopropyl isobutyrate has been investigated previously only once [3]. The most investigated compound of the series of interest for this Letter is isopropyl formate but only three groups have studied its kinetics [3][4][5].…”

“…Indeed, relatively high Cl atoms concentrations have been reported by different studies [1] indicating that the reactions of Cl can trigger a fast oxidation of volatile organic compounds and hence compete with the OH reactions. The other possible atmospheric degradation processes such as reactions with ozone, NO 3 and sunlight-induced photolysis are considered to be of minor importance.…”