Ring-cleavage Reactions of Aromatic Hydrocarbons Studied by FT-IR Spectroscopy. III. Photooxidation of 1,2,3-, 1,2,4-, and 1,3,5-Trimethylbenzenes in the NOx-Air System

Article abstract of DOI:10.1246/bcsj.58.2549

Photooxidation of 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes was carried out in the NOx-air system.Formation of glyoxal, methylglyoxal and biacetyl was observed in the case of 1,2,3- and 1,2,4-trimethylbenzenes, and only methylglyoxal was observed from 1,3,5-trimethylbenzene.Yield of glyoxal, methylglyoxal and biacetyl were 7, 18, and 45percent and 8, 37, and 11percent of trimethylbenzene consumed in cases of 1,2,3- and 1,2,4-trimethylbenzenes, respectively.The reaction mechanism which was used to explain the yields of α-dicarbonyl compounds from toluene and o-, m-, p-xylenes in the preceding paper (part II) has been applied to explain these yields, and has been found to reproduce these yields well.Formation of 3-hexene-2,5-dione was observed only from 1,2,4-trimethylbenzene.The fractions of the ring-cleavage process in the total reaction were 70, 56, and 64percent in cases of 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes, respectively.The yields of the ring-cleavage process are discussed.