Prediction of impact sensivity of nitro energetic compounds using QSPR approaches
Résumé
The new European régulation REACH aiming to reinforce the control of risksfrom chemicals in Europe entered into force in 2007. It may require the reassessment of hazardous properties for up to 140000 substances until 2018. However, the complète experimental characterization of (eco)toxicological and physico-chemical properties is time-consuming, costly and sometimes simply not feasible at the R&D stage. Therefore, the development of validated alternative methodsfor assessing hazardous properties ofchemicals is promoied in REACH. The présent work focuses on the development and validation of Quantitative Structure-Property Relationships (QSPR) models to predict the impact sensitivity ofpotentially explosive molécules (nitroaromatics, nitroaliphatics and nitramines,...). To set up appropriate relationships between différent molecular descriptors of thèse compounds and their impact sensitivity, an original approach associating the QSPR method to quantum chemical calculations was developed. More than 300 molecular descriptors (constitutional, topological, geometrical, quantum chemical) were calculated using CodessaPro software from calculated molecular structures, optimized with the Density Functional Theory (DFT) in GaussianO3 package. Thèses descriptors were integrated into statistical multilinear régressions to link them quantitatively to expérimental data obtained on the impact sensitivity property. In order to validate models according to the OECD principles for the use of QSPRs in a regulatory context, models were developed on a training dataset and their predictivity wasverified on a validation dataset. Once validated, models are expected to be integrated into a global toolfor the estimation of explosibility hazards of substances (for classification purposes) and the need for further expérimental testing