Refinement of Copper(II) Azide with 1-Alkyl-5H-tetrazoles: Adaptable Energetic Complexes

A concept for stabilizing highly sensitive and explosive copper(II) azide with 1-N-substituted tetrazoles is described. It was possible to stabilize the system by the use of highly endothermic, nitrogen-rich ligands. The sensitivities of the resulting energetic copper coordination compounds can be tuned further by variation of the alkyl chain of the ligands and by phlegmatization of the complexes with classical additives during the synthesis. It is demonstrated, using the compound based on 1-methyl-5H-tetrazole ([Cu(N-3)(2)(MTZ)], 1) that this class of complexes can be applied as a potential replacement for both lead azide (LA) and lead styphnate (LS). The complex was extensively investigated according to its chemical (elemental analysis, single-crystal and powder X-ray diffraction, IR spectroscopy, scanning electron microscopy) and physico-chemical properties (differential thermal analysis, sensitivities towards impact, friction, and electrostatic discharge) compared to pure copper(II) azide.