For example, Klotz et al. (1997, 1998) have shown that benzene oxide/oxepin photolyzes in sunlight to give phenol with a yield of 43.2 + 4.5%. This reaction mechanism is therefore feasible for the formation of phenol in the benzene-OH reaction. However, photolysis of toluene l,2-oxide/2-methyloxepin gave o-cresol only in small yields, 2.7 ± 2.2% (Klotz et al., 1998); this suggests that cresols formed in the OH-toluene reaction come primarily from the direct reaction (63) of the OH adduct with 02, in contrast to the conclusions of Moschonas et al. (f 999).

A variety of smaller multifunctional oxygenated compounds are also found as products of the gas-phase OH-aromatic reactions. Table 6.17 shows the yields of the smallest dicarbonyl compounds from these reactions, which, while small, are not insignificant. In addition to these products, a variety of other multifunctional compounds are typically found, the numbers, types, and concentrations of these products depending on the analytical methodologies used, the reaction conditions, and the skill and imagination of the experimentalist! Table 6.18, for example, shows some products observed in the photooxidation of toluene in air where the loss is due to attack by OH (Dumdei et al., f988). In this particular study, ~44% of the reacted toluene could be accounted for by the products shown in Table 6.18.

Similarly, Yu et al. (1997) and Yu and Jeffries (f997) report a total of 50 products from the oxidation of

TABLE 6.17 Fractional Yields of Dicarbonyl Compounds from the OH Reaction with Some Aromatic Hydrocarbons at 1 atm Total Pressure and 298 Ku
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