Two new energetic coordination compounds based on tetrazole-1-acetic acid: syntheses, crystal structures and their synergistic catalytic effect for the thermal decomposition of ammonium perchlorate

Abstract

Two new energetic coordination compounds {[Bi(tza)(C₂O₄)(H₂O)]·H₂O}_n (1) and [Fe₃O(tza)₆(H₂O)₃]NO₃ (2) (Htza = tetrazole-1-acetic acid) have been synthesized by a one-pot method and characterized by elemental analyses, IR spectroscopy, single crystal X-ray diffraction, a sensitivity test, thermogravimetric analyses (TG) and differential scanning calorimetry (DSC). The catalytic performances of 1 and 2 as well as the mixtures of compounds 1 and 2 for the thermal decomposition of ammonium perchlorate (AP) were investigated by DSC-TG. Compound 1 exhibits a 3D pillar-layer structure constructed of [Bi(C₂O₄)]⁺ layers and semi-rigid tza⁻ anions, and 2 shows cationic [Fe₃O(tza)₆]⁺ trigonal prismatic clusters with a zero-dimensional structure. Compounds 1 and 2 are thermally stable energetic compounds and were insensitive to impact and friction, and they all exhibit good catalytic action for AP thermal decomposition, and 2 has a higher catalytic activity for AP decomposition than 1. Moreover, a synergetic catalytic effect between 1 and 2 was observed, with a synergetic index of 1.31. Therefore, it is promising that the mixtures of compounds 1 and 2 could be used as the catalysts in AP solid propellants.