Relationship between the Bond Dissociation Energies and Impact Sensitivities of Some Nitro‐Explosives

ArticleinPropellants Explosives Pyrotechnics 31(4):306 - 310 · August 2006with11 Reads
DOI: 10.1002/prep.200600042
Abstract
The bond dissociation energy (BDE) for removal of the NO2 group for eleven CHNO nitro-containing explosive molecules is studied to find its correlation with impact sensitivity. The BDE for removal of the NO2 group in nitroaromatic molecules with nitro alkyl, and esters with nitro alkyl, is calculated using the B3LYP method of Density Functional Theory with the 6-31G* basis set. The relationship between the impact sensitivities and the weakest C-NO2 bond dissociation energy values is examined. The results indicate a nearly linear correlation between the impact sensitivity and the ratio of the BDE value to the total molecular energy.
    • "Because of the differences between operators, type of apparatus and ways of conducting experiments, the results obtained for the impact sensitivity of energetic materials vary from laboratory to laboratory [18]. There are several reports concerning investigations of the relationship between impact sensitivity and molecular structure [19, 20], bond dissociation energies [21], surface electrostatic potentials [22], friction sensitivity [23], molecular electronegativities [24, 25], activation energy of thermal decomposition [26], heats of fusion [27] and particle size of energetic materials [28]. Kočί and co-workers investigated the relationship between the electrostatic sensitivity of some poly nitro compounds and their impact sensitivity [15]. "
    Article · Jan 2016
    • "The remaining area of the molecule is the electropositive region. The impact sensitivity parameters of the energetic molecule are used to predict the molecule stability [40]. Here, we explore the concept proposed by Murray et al. [39] regarding the buildup of the positive electrostatic potential over the C—NO 2 bonding region and try to relate its impact sensitivity. "
    [Show abstract] [Hide abstract] ABSTRACT: The energetic parameters, such as density, bond strength, and sensitivity of explosives/ propellants decide their detonation power and safety. Experimentally, optimization of these parameters is found to be a difficult task; therefore, prior to synthesis, it makes sense to estimate these parameters by computational techniques, ab initio crystal structure prediction, and quantum chemical calculation coupled with the AIM analysis. Here, we predict the density of an energetic 2,4-dinitrobenzoic acid (DNBA) molecule from different ab initio crystal structure models and validate the results through comparisons with experimental data. The bond topological characterization reveals that the C NO2 bonds are the weakest bonds and are identified as sensitive bonds in the molecule. The bond sensitivity is estimated from Murray’s method. The impact sensitivity of this molecule is also calculated. Large negative electrostatic potential regions are found near the NO2 and carboxylic groups, which are the reactive sites of the molecule.
    Full-text · Article · Nov 2013
    • "Correlations were also proposed with the charge distribution descriptors [15], e.g. empirical molecular electronegativities [16,17], charge of nitro groups [18,19], electrostatic potential at the midpoint of the C-NO 2 bond (V mid ) [15,20,21], or the dissociation energy of this bond [20,22,23]. These correlations notably highlighted the critical part of the C-NO 2 bond in the decomposition process of nitro compounds [24]. "
    [Show abstract] [Hide abstract] ABSTRACT: New quantitative structure–property relationships were developed to predict accurately the impact sensitivity of nitro compounds from their molecular structures. Such predictive approaches represent good alternative to complete experimental testing in development process or for regulatory issues (e.g., within the European REACH regulation). To achieve highly predictive models, two approaches were used to explore the whole diversity of nitro compounds included in a dataset of 161 molecules. In the first step, local models, dedicated to nitramines, nitroaliphatics, and nitroaromatics, were proposed. After that, a global model was developed to be applicable for the whole range of the nitro compounds of the dataset. In both cases, large series of molecular descriptors were calculated from quantum chemically calculated molecular structures, and multilinear regressions were computed to correlate them with experimental impact sensitivities. Both the global and local models could predict nitramines and nitroaliphatics in high accuracy whereas nitroaromatics were more difficult to be predicted due to their complex decomposition mechanisms. The proposed models were validated in the perspective of potential regulatory use according to the OECD principles, including internal, external validation, and the definition of their applicability domain. So, they could then be used for prediction either separately or in a consensus approach. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
    Full-text · Article · Sep 2012
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