Methyl nitrate, photolysis

Photolytic. Photolysis of acetone in air yields carbon monoxide and free radicals, but in isopropanol, pinacol is formed (Calvert and Pitts, 1966). Photolysis of acetone vapor with nitrogen dioxide via a mercury lamp gave peroxyacetyl nitrate as the major product with smaller quantities of methyl nitrate (Warneck and Zerbach, 1992). 

Qualitative work on the photolysis of methyl nitrate suggests free radicals are formed via step (a) . In the photolysis of ethyl nitrate at 2654 A (a) seems to be the exclusive primary step at 3130 A there are some contributions from (b) and (c)... 

By combining the rate coefficient value for the OH reaction and a diurnally averaged OH concentration of 1 x 10 molecule cm , the atmospheric lifetime of methyl nitrate is estimated to be about 50 days. Photolysis is also an important tropospheric loss mechanism for CH3ONO2 (about 10 days for an overhead Sun see table IX-M-1). The reaction of OH with CH3ONO2 at ambient temperature may proceed by an H-atom... 

Imidazole, 2,4,5-trichloro-1-methyl-chlorination, 5, 398 Imidazole, 2,4,5-trideutero-iodination, 5, 401 Imidazole, 1-trifiuoroacetyl-reactions, 5, 451-452 Imidazole, 2-trifiuoromethyl-hydrolysis, 5, 432 Imidazole, 2,4,5-triiodo-nitration, 5, 396 synthesis, 5, 400 Imidazole, 1,2,4-trimethyl-photolysis, 5, 377 rearrangement, 5, 378 Imidazole, 1,2,5-trimethyl-photochemical rearrangement, 5, 377 rearrangement, 5, 378 Imidazole, 1,4,5-trimethyl-bromination, 5, 399 3-oxide... 

Pyrrole, 2-methyoxycarbonyl-1 -methyl-formylation, 4, 45 Pyrrole, nitro-rearrangement, 4, 297 Pyrrole, 2-nitro-nitration, 4, 211 photolysis, 4, 203 radical methylation, 4, 260 synthesis, 4, 210, 362 Pyrrole, 3-nitro- N NMR, 4, 13 nitration, 4, 211 synthesis, 4, 49, 210, 362 Pyrrole, nitroso-rearrangement, 4, 297 Pyrrole, 2-nitroso-reactions... 

Attention has been given to possible adverse effects of incorporating tert-butyl methyl ether into antomobile fuels. tert-Butyl formate is an established product of photolysis, and it has been shown that photolysis in the presence of NO can produce the relatively stable tert-butoxyformyl peroxynitrate. This has a stability comparable to that of peroxy-acetyl nitrate, and may therefore increase the potential for disseminating NO (Kirchner et al. 1997). 

The kinetics of the various reactions have been explored in detail using large-volume chambers that can be used to simulate reactions in the troposphere. They have frequently used hydroxyl radicals formed by photolysis of methyl (or ethyl) nitrite, with the addition of NO to inhibit photolysis of NO2. This would result in the formation of 0( P) atoms, and subsequent reaction with Oj would produce ozone, and hence NO3 radicals from NOj. Nitrate radicals are produced by the thermal decomposition of NjOj, and in experiments with O3, a scavenger for hydroxyl radicals is added. Details of the different experimental procedures for the measurement of absolute and relative rates have been summarized, and attention drawn to the often considerable spread of values for experiments carried out at room temperature (-298 K) (Atkinson 1986). It should be emphasized that in the real troposphere, both the rates—and possibly the products—of transformation will be determined by seasonal differences both in temperature and the intensity of solar radiation. These are determined both by latitude and altitude. 

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