Syntheses and Characterization of two cyclo-pentazolate salts

Two energetic salts of cyclo-N 5 − , O-methylisoure pentazolate ( 1 ) and guanidinoacetic acid pentazolate ( 2 ), were synthesized by metathesis reaction. All the energetic cyclo-N 5 − salts were characterized by single-crystal XRD, IR spectroscopy, 1 H and 13 C multinuclear NMR spectroscopy, thermal analysis (DSC) and elemental analysis. They exhibit good thermal stability with decomposition temperatures of more than 100 °C and they are in excellent agreement with those reported non-metallic salts. Salt 1 also exhibits strong π-π interactions. The standard enthalpies of formation and detonation performances of these salts were calculated using Gaussian 09 and EXPLO5 v6.01 programs. The detonation velocities of compound 1 and 2 are both about 7400 m s −1 and these two salts exhibit low mechanical sensitivity (IS>23 J, FS>220 N). Therefore, in this work, the synthesis of the new pentazolate salts enriches the cyclo-pentazolate salts system, which is conducive to the exploration of more heat-resistant and higher detonation velocities pentazolate salts.