Hexaamminecobalt(III) Cation as Multiple Hydrogen Bond Donors: Synthesis, Characterization and Energetic Properties of <i>cyclo</i>-Pentazolate and Azide Based Complexes
Yuangang Xu, Jianxin Zhou, Dongxue Li, Pengcheng Wang, Qiuhan Lin, Ming Lu
Abstract
A series of hexaaminocobalt(III) based energetic compounds [Co(NH3)6](N3)3 (1), [Co(NH3)6](N5)2(N3) (2), [Co(NH3)6](N5)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.