Alkaline Earth Metal Salts of 5‐Nitro‐2 H ‐tetrazole: Prospective Candidates for Environmentally Friendly Energetic Applications

Deprotonation of ammonium 5‐nitrotetrazolate in aqueous or alcoholic solution upon reaction with a suitable alkaline earth metal (M 2+ ) hydroxide or carbonate (M 2+ = Mg 2+ , Ca 2+ , Sr 2+ or Ba 2+ ) leads to the synthesis of a family of sensitive energetic metal salts based on the 5‐nitrotetrazolate anion (NT – ). These new compounds were characterized by IR, Raman and NMR ( 1 H, 13 C and 14 N) spectroscopy as well as by mass spectrometry and elemental analysis. In addition, the crystal structure of the calcium salt was determined by low‐temperature X‐ray measurements [orthorombic, space group Pna 2; a = 6.8960(2), b = 32.575(1), c = 6.2399(2) Å; V = 1401.73(8) Å 3 ]. All compounds show good thermal stabilities at or above 180 °C, as proved by DSC measurements, and the sensitivity of the salts towards impact and friction increases with the size of the cation (Mg < Ca < Sr < Ba). Lastly, the 5‐nitro‐2 H ‐tetrazole salts presented here show promise for future use as energetic compounds.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)