Theoretical insight into the effect of solvent polarity on the formation and morphology of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20)/2,4,6-trinitro-toluene(TNT) cocrystal explosive

Autor: Chun-lei Wu, Gang Han, Fu-de Ren, Shuang-fei Zhu, Rui-jun Gou, Shu-hai Zhang
Rok vydání: 2018
Předmět:
Zdroj: Computational and Theoretical Chemistry. 1127:22-30
ISSN: 2210-271X
Popis: Molecular dynamics simulations were employed to study the effect of solvents of varying polarity on the formation and morphology of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20)/2,4,6-trinitro-toluene(TNT) cocrystal explosive. Six solvents, i.e. n-heptane, toluene, ethanol, acetonitrile, methanol and dimethyl sulfoxide with a wide range of polarity were used. The cocrystal morphology was predicted by Growth Morphology Model. The surface conformation and polarity were used to estimate the molecular parking of cocrystal surface. The interaction energies and binding energies were used to determine the influence of solvent properties (i.e. polarity, permittivity, molecule weight and vapor pressure) on the formation and morphology. The results indicate that the predicted morphology of CL-20/TNT cocrystal is dominated by the (0 0 2), (1 1 1), (0 2 0) and (0 2 1) in vacuum. CL-20/TNT cocrystal is easier to form in moderately polar solvents, that is, ethanol and acetonitrile. CL-20 molecules are more inclined to interact with TNT in (1 1 1) and (0 2 1) CL-20/TNT-solvent interfaces than in (0 0 2) and (0 2 0) interfaces. The predicted cocrystal morphology is in good agreement with the experimental morphology in ethonal solution. In addition, radial distribution function (RDF) analyses further proved the existence of interactions between the cocrystal faces and solvents.
Databáze: OpenAIRE