Energy barriers to gas-phase unimolecular decomposition of trinitrotoluenes

Abstract

Alternative versions of gas-phase unimolecular decomposition of six isomeric trinitrotoluenes, in particular homolytic dissociation of Carom–NO2 and Carom–CH3 bonds, nitro–nitrite rearrangement, intramolecular hydrogen transfer from the methyl group to nitro group with formation of aci-trinitrotoluenes, and formation of various bicyclic intermediates, have been simulated at the B3LYP/6-31+G(2df,p) level of theory. Except for 3,4,5-trinitrotoluene, the most energetically favorable for all other examined trinitrotoluenes is intramolecular hydrogen transfer. 3,4,5-Trinitrotoluene preferentially decomposes via formation of [6 + 4]-bicyclic intermediates or homolytic dissociation of the Carom–NO2 bond.