Synthesis, Characterization And Performance Of Energetic Nitroimidazole Derivatives

In this paper, the synthesis, characterization, crystal structure and performance of nitroimidazoles were studied systematically, especially4-nitroimidazole derivatives, dinitroimidazoles and their derivatives, and2-azido-4-nitroimidazole and its derivatives.A series of N-polynitroaryl derivatives of4-nitroimidazole have been synthesized under CuI/TBAB catalytic system in excellent yields, including1-(2,4,6-trinitrophenyl)-4-nitroimidazole,1-(3-amino-2,4,6-trinitrophenyl)-4-nitroimidazole,1-(3,5-diamino-2,4,6-trinitrophenyl)-4-nitroimidazole,3,5-di-(4-nitroimidazole)-2,4,6-trinitrobenzenamine,3,5-dinitro-2-(4-nitroimidazol-1-yl)pyridin-4-amine.1-(3-amino-2,4,6-trinitrophenyl)-4-nitroimi-dazole was structurally determined by single-crystal X-ray diffraction, it belongs to the Monoclinic system, space group P21/N.A series of dinitroimidazoles derivatives have been synthesized using TBAB as phase transfer catalyst, including1-(2,4,6-trinitrophenyl)-2,4-dinitroimidazole1,1-(3-amino-2,4,6-trinitrophenyl)-2,4-nitroimidazole2,1-(3,5-diamino-2,4,6-trinitrophenyl)-2,4-dinitroimi-dazole3,1-(2,4,6-trinitrophenyl)-4,5-dinitroimidazole4,1-(3-amino-2,4,6-trinitrophenyl)-4,5-nitroimidazole5,1-(3,5-diamino-2,4,6-trinitrophenyl)-4,5-dinitroimidazole6, and the crystal structure of1,3,4,5,6were studied comparatively.1belongs to the Monoclinic system, space group P21/N;3belongs to the Monoclinic system, space group P21/N;4belongs to the Orthorhombic system, space group P212121;5belongs to the Orthorhombic system, space group P212121;6belongs to the Orthorhombic system, space group P212121.It indicated that the densities were increased as two amino groups were introduced, but decreased as one amino group. The thermal stabilities of the related compounds were studied by DSC, and all of the derivatives decomposed between250and350℃, and their thermal stability decreased as the number of amino groups increased. Impact sensitivity of2,3,5,6is92%,76%,64%and76%, and friction sensitivity80%,36%,76%and48%, respectively.2-azido-4-nitroimidazole was synthesized by two methods, and then2-azido-4,5-dinitroimidazole,1-(2,4,6-trinitrophenyl)-2-azido-4-nitroimidazole and1-(3-amino-2,4,6-tri-nitrophenyl)-2-azido-4-nitroimidazole were obtained further.2-azido-4-nitroimidazole-based energetic salts were synthesized by the reaction of2-azido-4-nitroimidazole with ammonium carbonate, guanidine carbonate, and concentrated nitric acid, respectively, and the structures of these new salts were determined.2-azido-4-nitroimidazole was structurally determined by single-crystal X-ray diffraction, it belongs to the Monoclinic system, space group P21/N; 1-(2,4,6-trinitrophenyl)-2-azido-4-nitroimidazole belongs to the Orthorhombic system, space group Pbca;1-(3-amino-2,4,6-trinitrophenyl)-2-azido-4-nitroimidazole belongs to the Orthorhombic system, space group Pbca.Detonation velocity and detonation pressure of the six dinitroimidazoles derivatives were calculated by using the B3LYP functional in Gaussian09program suite, and their values are distributed from8.28to8.48km/s and31.36to32.82GPa, respectively. The calculated values of2-azido-4-nitroimidazole and its derivatives fall in the range of7.49to8.41km/s and24.12to31.70GPa, respectively. The calculated values of trinitroimidazole derivatives are distributed from8.6to9.4km/s and34to41GPa, respectively. The HOFs of2-azido-4-nitroimidazole-based energetic salts are within the range292-338kJ/mol, and their detonation velocities and pressures are distributed from7.3to8.6km/s and18to33GPa, respectively.