Synthesis of 1-(2H-tetrazol-5-yl)-5-nitraminotetrazole and its derivatives from 5-aminotetrazole and cyanogen azide: a promising strategy towards the development of C–N linked bistetrazolate energetic materials. Issue 39 (27th September 2017) - Wang, Binshen
Abstract : A series of C–N linked bistetrazolate nitramino compounds were successfully prepared with excellent detonation performance coupled with moderate sensitivities. Abstract : A series of C–N linked bistetrazolate nitramino compounds, i.e., 1-(2 H -tetrazol-5-yl)-5-nitraminotetrazole (2 ) and its energetic salts (3–8 ), were successfully prepared from readily available 5-aminotetrazole. All new energetic compounds were fully characterized by IR and NMR spectra and elemental analysis, and six of them (1, 3–7 ) were further determined by single-crystal X-ray diffraction analysis. The nitrogen contents of these energetic bistetrazolate compounds, ranging from 59.3% (3 ) to 74.8% (7 ), are much higher than those of the commonly used high explosives such as RDX (N: 37.8%), HMX (N: 37.8%) and CL-20 (N: 38.3%). And theoretical calculations by using the Gaussian 09 program package demonstrate that compounds1–8 have high positive heats of formation, of which the heats of formation of ammonium salt4 (3.60 kJ g −1 ), aminonitroguanidinium5 (3.11 kJ g −1 ) and dihydrazinium salt7 (3.25 kJ g −1 ) are approximately eight times higher than those of RDX (0.39 kJ g −1 ) and HMX (0.39 kJ g −1 ), and four times higher than that of CL-20 (0.83 kJ g −1 ). The high nitrogen contents and high heats of formation have endowed these energetic compounds with prominent detonation performance. It is noteworthy that compound7 exhibits an excellent calculated detonation velocity of 9822 m s −1 superior to that of CL-20 (9730 m s −1 ), while the impact and friction sensitivities of7 (IS = 8 J, FS = 192 N) are comparable to those of HMX (IS = 7 J, FS = 112 N). The good detonation properties with moderate sensitivities demonstrate that compound7 is a promising candidate for application as a high-performance energetic material.