Decomposition mechanisms of trinitroalkyl compounds: a theoretical study from aliphatic to aromatic nitro compounds

Abstract

The chemical mechanisms involved in the decomposition of trinitroethyl compounds were studied for both aliphatic and aromatic derivatives using density functional theory calculations. At first, in the case of 1,1,1-trinitrobutane, used as a reference molecule, two primary channels were highlighted among the five investigated ones: the breaking of the C-N bond and the HONO elimination. Then, the influence of various structural parameters was studied for these two reactions by changing the length of the carbon chain, adding substituents or double bonds along the carbon chain. If some slight changes in activation energies were observed for most of these features, no modification of the competition between the two investigated reactions was highlighted and the breaking of the C-N bond remained the favoured mechanism. At last, the reactions involving the trinitroalkyl fragments were highlighted to be more competitive than reactions involving nitro groups linked to aromatic cycles in two aromatic systems (4-(1,1,1-trinitrobutyl)-nitrobenzene and 2-(1,1,1-trinitrobutyl)-nitrobenzene). This showed that aromatic nitro compounds with trinitroalkyl derivatives decompose from their alkyl part and may be considered more likely as aliphatic than as aromatic regarding the initiation of their decomposition process.

Chemoinformatics for the Safety of Energetic and Reactive Materials at Ineris

“…At first, nitro groups are among the functional groups identified as associated to explosive properties [6] . Secondly, the primary cleavage of the C‐NO 2 bond is known as critical in the decomposition mechanism of nitroaliphatic compounds [107] …”

“…[6] Secondly, the primary cleavage of the C-NO 2 bond is known as critical in the decomposition mechanism of nitroaliphatic compounds. [107] After examination by the expert comity, this model was accepted and implemented into version 3.3 of the QSAR Toolbox in December 2014. Two other simple models were proposed recently by Ineris: for the impact sensitivity of nitramines (Eq.…”