2,2-Bis(5-tetrazolyl)propane as Ligand in Energetic 3d Transition Metal Complexes

This contribution covers the preparation and characterization of 2,2-bis(5-tetrazolyl)propane (5-DTP) (1). The bridged bitetrazole is used as a neutral nitrogen-rich ligand in 3d transition metal(II) based complexes for the first time and can be synthesized via [2+3] cycloaddition from sodium azide and dimethylmalononitrile. The combination with different anions (e.g., perchlorate, nitrate, sulfate, and chloride) yields materials with widely varying physicochemical properties. The obtained coordination compounds were characterized using low-temperature single-crystal X-ray diffraction (except 14), IR spectroscopy, elemental analysis, and DTA (except 16). The sensitivities toward external stimuli (impact and friction) were determined according to the Bundesamt fur Materialforschung und -prufung (BAM) standard methods together with its sensitivities against electrostatic discharge (except 16). Complexes 10 and 14 were characterized in laser ignition experiments. For determination of the compounds' deflagration to detonation transition (DDT) capability, hot plate and hot needle tests were performed for the zinc(II) and copper(II) perchlorate complexes.