Synthesis and Characterization of Asymmetric 1,2‐Dihydroxy‐5,5′‐bitetrazole and Selected Nitrogen‐Rich Derivatives

A selective synthesis of asymmetric 1,2′‐dihydroxy‐5,5′‐bitetrazole monohydrate (4·H2O) from inexpensive starting materials is presented. This bitetrazole derivative contains two N‐oxides at the N1 and at the N2′ position, which both increase the energetic performance. Various energetic salts, such as hydroxylammonium (5), tetraaminobitriazolium (10), and triaminotriazolotriazolium (11) were synthesized. Neutral 4 and hydroxylammonium salt 5 were compared in detail with other tetrazole mono‐ and di‐N‐oxides to gain a deeper insight into the performance increment of N‐oxides in tetrazoles. Compounds 3–5, 9, and 11 were structurally characterized by using single‐crystal X‐ray diffraction. Additionally, all new compounds were characterized by using NMR, IR and Raman spectroscopy, mass spectrometry, elemental analysis as well as differential thermal analysis (DTA) measurements. The sensitivities of the compounds toward shock, friction, and electrostatic discharge were determined. Finally, the heats of formation were calculated and several detonation parameters were computed with the EXPLO5 v. 6.01 code.