Three Novel Insensitive Energetic Cocrystals

Sensitivity which is related to security is the paramount considerations of energetic materials. Cocrystallization is proposed as an effective method to modify the physic-chemical properties of energetic materials, e.g. density, sensitivity and solubility, thus adjusting their properties to satisfy engineering application. The intermolecular interactions of1-nitronaphthalene with TNT, picric acid and MHN were calculated by Gaussian03software. The results showed that1-nitronaphthalene formed intermolecular hydrogen bonds with TNT, picric acid and MHN. The single crystals of1-nitronaphthalene/TNT cocrystal and1-nitronaphthalene/picric acid cocrystal were prepared by solvent-evaporating method and their crystal structures were characterized by single X-ray diffraction (SXRD). The powder of1-nitronaphthlane cocrystals was prepared by melting method and was studied by powder XRD, differential scanning calorimetry (DSC), Raman spectrum and infrared spectrum. The results show that dramatic change in the spectra relative to pure components is due to strong intermolecular interactions exist in the cocrystals.Properties of1-nitronaphthalene cocrystals changed dramatically, especially the sensitivity and melting point of TNT, picric acid and MHN dramatically decreased. Low melting point, insensitivity and good explosive properties make1-nitronaphthalene cocrystals prone to be utilized as Melt-cast explosive, especially cocrystal Ⅲ which melts at92.17℃and is more powerful than TNT.The electrostatic potential surface of1-nitronaphthalene showes that this insensitive material contains a wide range of positive electrostatic potential which leads it prone to cocrystallize with electron-poor energetic materials and modifies their sensitivity. Except for insensitivity,1-nitronaphthalene adopts low density and oxygen balance, these properties are inevitable introduced to cocrystal system. Thus high density insensitive energetic cocrystal requires high density insensitive components to crystallize together.