Hexaamminecobalt(III) Cation as Multiple Hydrogen Bond Donors: Synthesis, Characterization and Energetic Properties of cyclo-Pentazolate and Azide Based Complexes

Abstract

A series of hexaaminocobalt(III) based energetic compounds [Co(NH 3 ) 6 ](N 3 ) 3 (1), [Co(NH 3 ) 6 ](N 5 ) 2 (N 3 ) (2), [Co(NH 3 ) 6 ](N 5 ) 3 (3), and their chloride and nitrate complex salts 4−6 were designed and synthesized by simple metathesis reactions. As far as we know, compound 3 is the first trivalent metal pentazolate salt. The structures of all the new energetic compounds were confirmed by single-crystal X-ray diffraction. Their physicochemical and energetic properties, such as density, thermal stability, sensitivity, and detonation properties, were also evaluated. Due to the extensive hydrogen bonding network, the detonation properties of these salts and acceptable mechanical sensitivities (IS = 3−6 J, FS = 40−80 N) hold the prospective potential as green primary explosives. This work suggests that the cyclo-pentazolate anion has good compatibility with azide and nitrate ions, and they can act together as hydrogen bond acceptors to form novel energetic materials with controllable properties through hydrogen bonds.

Preparation of High-Energy ECPs by Retaining the Coordination Ability of Carbohydrazide Groups

“…Due to their extremely short DDT (deflagration-to-detonation transition) time, it can be triggered by very small stimuli and release tremendous amounts of energy (such as heat and shock waves) in a very short time . With the deepening of research and the development of interdisciplinary fields, more and more new materials are being used in primary explosives, such as ionic salts, metal salts, and organics. − Among them, energetic coordination polymers (ECPs) have attracted widespread attention from researchers due to their novel structures and excellent properties, and the contribution made by Klapötke is particularly prominent in this field. − …”