2,2'-Azobis(1,5'-bitetrazole) with a N Chain and 1,5'-Bitetrazolate-2-oxides: Construction of Highly Energetic Nitrogen-Rich Materials Based on C-N-Linked Tetrazoles.

A series of high-nitrogen compounds, including a unique molecule 2,2'-azobis(1,5'-bitetrazole) with a branched N chain and 1,5'-bitetrazolate-2-oxides, were synthesized successfully based on C-N-linked 1,5'-bistetrazoles using azo coupling of -amine bonds and -oxide introduction strategies. All compounds were characterized by NMR spectroscopy, IR spectroscopy, elemental analysis, and differential scanning calorimetry, in which the structures of five compounds were further determined by single-crystal X-ray diffraction analysis (, , , , and ). The nitrogen contents of these five compounds range from 63.62 () to 83.43% (), which are much higher than that of CL-20 (38.34%). The heat of formation for the prepared compounds was calculated by using the Gaussian 09 program, with having the highest value of 5.13 kJ g, about 6 times higher than that of CL-20 (0.83 kJ g). The calculated detonation performances by EXPLO5 v6.05.04 show that has excellent detonation performance ( = 9581 m s, = 35.93 GPa) and a remarkable specific impulse ( = 284.9 s).