Info

" From Atkinson (1989). 6 From Tuazon et al. (1994). ' Assuming [oh] = 1 X 10f' radicals cm-3. ''Assuming [O,] = 100 ppb = 2.5 X 1012 molecules cirT3. ' Carl and Crowley (1998). r Koch et al. (1996). Koch et al. (1997).

" From Atkinson (1989). 6 From Tuazon et al. (1994). ' Assuming [oh] = 1 X 10f' radicals cm-3. ''Assuming [O,] = 100 ppb = 2.5 X 1012 molecules cirT3. ' Carl and Crowley (1998). r Koch et al. (1996). Koch et al. (1997).

6. GAS-PHASE REACTIONS IN IRRADIATED ORGANIC-NOv-AIR MIXTURES

temperatures and the associated atmospheric lifetimes under typical, moderately polluted tropospheric conditions. As might be expected, OH reacts quite rapidly with the simple amines. Perhaps somewhat surprising, however, are the relatively rapid reactions of di- and trimethylamine with 03.

The N-H bond strength in CH3NH2 is -100 kcal mol~', stronger than the C-H bond at 93 kcal mol~'. Similarly, in (CH3)2NH, the N-H bond strength is ~92 kcal mol-1, compared to 87 kcal mol-1 for the C-H bond. One might expect abstraction of a C-H hydrogen to predominate in these reactions, and this appears to be the case. For example, for (CH3)2NH, Lindley et al. (1979) report that 63% of the reaction occurs by (80a),

OH + (CH3)2NH -> H20 + CH2NHCH3, (80a) and the remainder by (80b):

(ch3)2ncho i /hcho

CHoNOp

CH3NO2 jy

K^jMACT,

(ch3)2nch2n(ch3)2

(ch3)2nch2n(ch3)2

Was this article helpful?

0 0

Post a comment