Reactions of OH N03 and CI

Table 6.19 gives the room temperature rate constants for the reactions of some oxygen-containing or-ganics with OH as well as with N03 and with chlorine atoms. As expected, the OH reactions are reasonably fast, ranging from ~10-13 cm3 molecule-1 s-1 with acetone to more than 10"11 cm3 molecule-1 s-1 with the aldehydes, furan, and, in general, compounds having an alkyl group larger than -CH-,. Chlorine atoms also react very quickly. The N03 reactions in most cases are sufficiently slow that OH is the only significant tropospheric oxidant on a global basis for these oxygenated compounds. However, N03 can play a role in aldehyde oxidations, especially at night when OH levels are very low.

Aldehydes. Reactions with aldehydes occur by abstraction of the relatively weak (~ 87 kcal mol-1) alde-hydic hydrogen:

The RCO radical produced then adds 02 as expected. For example, for acetaldehyde, reaction (65) is followed by

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