Energetic Improvements by <i>N</i>-Oxidation: Insensitive Amino-Hydroximoyl-Tetrazole-2<i>N</i>-Oxides

<div><p>5-Aminohydroximoyl-2-hydroxytetrazole (<b>3</b>) was synthesized in a three-step synthesis from inexpensive starting materials. This novel tetrazole derivative contains two energetic moieties: an N-oxide as well as an aminohydroximoyl group. Various energetic nitrogen-rich salts such as hydroxylammonium (<b>4</b>), guanidinium (<b>5</b>), aminoguanidinium (<b>6</b>), ammonium (<b>7</b>), and triaminoguanidinium (<b>8</b>) were synthesized. Moreover, zwitterionic 5-amidrazonyl-tetrazole-2-oxide monohydrate (<b>9</b>) was synthesized. Compounds <b>4</b>, <b>5</b>, <b>8</b>, <b>9</b>, and <b>10</b> were structurally characterized using single-crystal X-ray diffraction. Additionally, all new compounds were characterized using nuclear magnetic resonance (NMR) and vibrational (infrared [IR], Raman) spectroscopy as well as mass spectrometry and elemental analysis. The thermal behavior was studied using differential thermal analysis (DTA) measurements and the sensitivities of the compounds toward shock, friction, and electrostatic discharge were determined. Finally, the enthalpies of formation were calculated (atomization method, CBS-4 M enthalpies) and several detonation/propulsion parameters computed with the EXPLO5 code.</p>