Synthesis and characterization of 5-(1,2,4-triazol-3-yl)tetrazoles with various energetic functionalities

Abstract

In this contribution the synthesis and full structural as well as spectroscopic characterization of three 5-(1,2,4-triazol-3-yl)tetrazoles along with selected energetic moieties like nitro, nitrimino, and azido groups are presented. The main goal is a comparative study on the influence of those variable energetic moieties on structural and energetic properties. A complete characterization including IR and Raman as well as multinuclear NMR spectroscopy of all compounds is presented. Additionally, X-ray crystallographic measurements were performed and reveal insights into structural characteristics as well as inter- and intramolecular interactions. The standard enthalpies of formation were calculated for all compounds at the CBS-4M level of theory and reveal high positive heats of formation for all compounds. The calculated detonation parameters (using the EXPLO5.05 program) are in the range of 8000 m s(-1) (8097 m s(-1) (5), 8020 m s(-1) (6), 7874 m s(-1) (7)). As expected, the measured impact and friction sensitivities as well as decomposition temperatures strongly depend on the energetic moiety at the triazole ring. The C-C connection of a triazole ring with its opportunity to introduce a large variety of energetic moieties and a tetrazole ring, implying a large energy content, leads to the selective synthesis of primary and secondary explosives.