Chapter 6: Chemistry of Aminated 5-Azidotetrazoles: How to Make Sensitive Materials Even More Sensitive

5-Azidotetrazole is a notorious compound, which has gained attention mainly due to its enormous sensitivity, but also due to its extremely high energy content in the explosive’s chemistry community. To date, only very few compounds based on 5-azidotetrazole have been described in the literature (for example, 1- and 2-hydroxy-5-azidotetrazole, ionic derivatives of 5-azidotetrazole or C2N14). Despite or perhaps precisely because of its high sensitivity, the 5- azidotetrazole backbone offers a high synthetic incentive for the generation of further energetic compounds. In this study, we report the N-aminated species of 5-azidotetrazole, 1-amino-5-azidotetrazole (1), which is obtained by diazotization of triaminoguanidinium hydrochloride, and 2-amino-5- azidotetrazole (2), which is accessible through amination (using THA) of 5- azidotetrazole. Synthetic efforts include the nitration of amino-5-azidotetrazoles to nitramino-5-azidotetrazole derivatives and dimerisation by oxidative azo coupling, which results in the formation of azo-(bis-5-azidotetrazole) (C2N16). The obtained compounds were structurally characterised by X-ray diffraction experiments. In addition, they were further characterised by IR, multinuclear NMR, DTA and sensitivity measurements. Based on the crystallographic density and the calculated enthalpy of formation (CBS-4M or CBS-QB3), their detonation parameters were computed using the EXPLO5 code.