Synthesis and Characterization of Binary, Highly Endothermic, and Extremely Sensitive 2,2'-Azobis(5-azidotetrazole).

2,2'-Azobis(5-azidotetrazole) (C 2 N 16 , 3 ), a highly energetic nitrogen-rich binary CN compound was obtained in a three-step synthesis through the formation of 5-azidotetrazole ( 1 ), subsequent amination using O -tosylhydroxylamine to give 2-amino-5-azidotetrazole ( 2 ), and oxidative azo coupling of 2 using t BuOCl as an oxidant in MeCN. A nitrogen:carbon ratio of 8:1, eight nitrogen atoms in a row, and a nitrogen content of over 90% was unknown for a binary heterocyclic compound until now. The successful isolation was confirmed through X-ray diffraction as well as by vibrational and 13 C NMR spectroscopy. C 2 N 16 can explode instantly and shows mechanical sensitivities far higher than quantitatively measurable. Nevertheless, it features interesting energetic performances, which were calculated using different quantum-chemical methods.