REACTIONS OF OXYGEN-CONTAINING ORGANICS

FIGURE 6.16 Formation of polyketones in the OH reaction with p-xylene (adapted from Wiesen et al 1995). 

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 

From Langer and Ljungstrom (1994). r From Rudich et al. (1996). 1 From Rudich et al. (1995). From Teton et al. (1996). 

Ketones. Reactions of ketones are similar to those of alkanes, with abstraction by OH, N03, and Cl occurring from the alkyl chains. In the case of acetone, for example, these reactions generate the radical CH3C0CH202 in air. As for typical R02, this reacts rapidly with NO (k m = 8 X 10 12 cm3 molecule-1 s 1) and with N02 ( 29x = 6.4 X 10-12 cm3 molecule -1 s-1) (Sehested et al., 1998b), giving calculated lifetimes with respect to reaction with 100 ppt each of NO and N02 of about 1 min. In remote areas where the NOx concentrations can be much smaller (see later and Chapter 11), reactions of CH3C0CH202 with H02 and other R02 may also become important. 

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H. REACTIONS OF OXYGEN-CONTAINING ORGANICS TABLE 6.19 (Continued) 215... 

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