Quantitative structure-property relationship studies for predicting explosibility of nitroaromatic compounds
Résumé
The new European regulation of chemicals named REACH (for "Registration, Evaluation and Authorization of CHemicals", published by the European Commission in December 2006) implies that a tremendous number of substances (up to 30000) may require a new assessment of hazardous properties. Therefore, there is a growing interest in evaluating capabilities of predictive methods for assessing hazardous properties of chemical substances as a screening process. If Quantitative Structure-Property Relationship (QSPR) type methods have been up to now mainly devoted to screening toxic properties, their use to establish relationships between the explosibility of dangerous substances and structural, energetic or physicochemical descriptors could lead to new perspectives. This contribution focuses on the case of a series of nitroaromatic compounds, which are all expected to present more or less severe explosive properties due to the presence of the nitro group. In particular, this paper shows that a multilinear regression model links correctly adequate molecular descriptors of nitroaromatic compounds with thermal stability (taken as a macroscopic property related to explosibility). The descriptors are mostly obtained by ab initio quantum chemical calculations. Moreover, we present a detailed theoretical investigation on the decomposition pathways of substituted nitrobenzenes using quantum chemical methods that provide pertinent information for the use of descriptors in relation with energetic aspects to access to more robust QSPR models