Single-Pulse Shock-Tube Studies on C-NO2 Bond Cleavage during the Decomposition of Some Nitro Aromatic Compounds

摘要

Nitrobenzene (NB), o-nitrotoluene (o-NT), and p-nitrotoluene (p-NT) have been decomposed in single-pulse shock-tube experiments. The rate expressions for C-NO2 bond cleavage have been found. These lead to a recombination rate of phenyl + NO2 in the 400,000,000 - 1,200,000,000L/(mol.s) range. Although this is the primary process in nitrobenzene and p-nitrotoluene decomposition, an isomerization reaction involving the formation of the nitrite proceeds under our conditions at less than half the rate of C-NO2 bond cleavage. o-Nitrotoluene is more thermally labile. From mass balance considerations it is clear that neither C-NO2 bond breaking nor NO2 isomerization is the primary decomposition channel. Instead, the former proceeds at about one-third the overall rate. The results are compared with recently published studies using the laser-enhanced pyrolysis technique and some disturbing differences are noted.