Inorganic chemistry laboratory experiment on an energetic nickel (II) coordination compound, aimed at third-year undergraduate students

This inorganic chemistry laboratory experiment, aimed at third-year undergraduate students, focuses on an energetic coordination compound, tris(hydrazine)nickel(II) nitrate [Ni(N2H4)(3)][NO3](2). As long as the solid is not subject to mechanical stimuli (impact and friction), it can be safely synthesized and handled. In our laboratory conditions (see supplementary information), the experiment includes synthesis of [Ni(N2H4)(3)][NO3](2) in two different morphologies, visual inspection of the samples, analysis by IR spectroscopy, checking the crystallinity by powder X-ray diffraction, 3D visualization of the crystal structure by means of a free program, and observation by scanning electron microscopy. In that respect, the experiment, as a whole, introduces students to nickel(II) complexes, coordination compounds, energetic materials, sonochemical and morphology-controlled syntheses, and a 3D visualization program for crystal structures and structural models. This laboratory experiment is also proposed in the form of alternate (light) versions so that it can be adopted in another inorganic chemistry laboratory that may have restrictions in terms of equipment, and in another third-year curriculum.