Synthesis of Functionalized Tetrazenes as Energetic Compounds

1,4-Bis[1-(2-hydroxyethyl)-1H-tetrazol-5-yl]-1,4-dimethyl-2-tetrazene (12a), 1,4-bis[1-isopropoxycarbonylmethyl-1H-tetrazol-5-yl]-1,4-dimethyl-2-tetrazene (12b), and 1,4-bis[1-carboxymethyl-1H-tetrazol-5-yl]-1,4-dimethyl-2-tetrazene (13) have been synthesized as new nitrogen-rich compounds. The tetrazenes were obtained by oxidation of the corresponding tetrazolylhydrazines using bromine. Moreover, a new method to prepare tetrazolylhydrazines in high yield using 5-bromotetrazoles has been developed. 12a, 12b, and 13 were characterized using vibrational spectroscopy (IR, Raman), mass spectrometry, and multinuclear NMR spectroscopy. The crystal structures of 12a, 12b, and 13 were determined using single crystal X-ray diffraction. Furthermore, the energetic properties of 12a, 12b, and 13 have been investigated using DSC and bomb calorimetric measurements. The sensitivity data toward impact and friction has been determined using BAM methods.