Nitrogen-Rich Copper(II) Bromate Complexes: an Exotic Class of Primary Explosives †.

Abstract

Because of the ongoing very challenging search for potential replacements of the currently used toxic lead-based primary explosives, new synthetic strategies have to be developed. In particular, the smart concept of energetic coordination compounds (ECC) has proven to hold great potential to solve this difficult and complex problem. The herein-described approach combines the exotic and neglected class of copper(II) bromate ECC with different environmentally friendly nitrogen-rich heterocycles, which exhibit the energetic properties of powerful primary explosives. The concept is the simple adjustment of the energetic properties of the complexes through alteration of the corresponding azoles. Six new copper(II) bromate complexes with reasonable sensitivities are featured in this study, which were synthesized in a practical and straightforward fashion, assured through easy access to copper(II) bromate obtained by metathesis reaction. Obtained compounds were comprehensively characterized through various analytical methods such as low-temperature X-ray diffraction, IR spectroscopy, and elemental analysis. Their sensitivities toward impact and friction were assessed through BAM standard techniques, together with their sensitivity against electrostatic discharge. Evaluation of the energetic properties of the newly synthesized compounds included examination of the respective thermal stabilities by differential thermal analysis. Furthermore, the complexes were tested regarding their behavior toward laser irradiation. Additionally, to receive insight into a possible correlation between the laser-investigated compounds' optical absorption and their ability to ignite by exposure to laser irradiation, UV-vis-near-IR spectra were recorded.