Synthesis and characterization of various photosensitive copper(II) complexes with 5-(1-methylhydrazinyl)-1H-tetrazole as ligand and perchlorate, nitrate, dinitramide, and chloride as anions.

The preparation of 5-(1-methylhydrazinyl)-1H-tetrazole monohydrate (1⋅H2O) and various copper(II) complexes with perchlorate (2 and 3), nitrate (4, 5, and 6), dinitramide (7), and chloride (8) is described. The coordination compounds (monomers, dimers, and polymers) were characterized through infrared spectroscopy and elemental analysis. Further, the structures of 2 and 4-8 were determined by single-crystal X-ray diffraction. Compound 1 can act as a bidentate ligand in its neutral form (HMHT) and as a μ2- or μ3-bridging ligand in its deprotonated form (MHT). The energetic properties of the synthesized complexes, such as their sensitivities toward impact and friction, were determined, and laser ignition tests were performed. New information about the laser initiation process and the role of the anion in the initiation criterion was obtained. The perchlorate complexes 2 (T(decomp)=217 °C) and 3 (T(decomp)=206 °C) are potential primary explosives.