ARTICLE This journal isThe connection of highly endothermic heterocycles with high nitrogen but also oxygen content is a recent trend in the development of new energetic materials in order to increase densities and stabilities. Bis(1-hydroxytetrazolyl)furazane (9) and bis(1-hydroxytetrazolyl)furoxane (10) were synthesized for the first time from dicyanofurazane and dicyanofuroxane, respectively. Several nitrogen-rich (e.g. ammonium and hydroxylammonium) and metal salts thereof were prepared. Most compounds were characterized by single crystal X-ray diffraction. In addition all compounds were analyzed by vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis and DSC measurements. The heats of formation of 4, 5, 15-16, 20 and 24 were calculated using the atomization method based on CBS-4M enthalpies. With these values and the experimental (X-ray) densities several detonation parameters such as the detonation pressure, velocity, energy and temperature were computed using the EXPLO5 code (V.5.05). In addition, the sensitivities towards impact, friction and electrical discharge were tested using the BAM drop hammer and friction tester as well as a small scale electrical discharge device.

During outstanding research in the late 1950s in Munich, which led to the development of the Wacker process for converting ethene into acetaldehyde by catalysis of PdCl 2 , black insoluble nitrosyl-palladium chloride (PdCl(NO)) was obtained. More than sixty years after its first synthesis, its crystal structure was now determined by X-ray diffraction. PdCl(NO) (mP16, P2 1 /c, a = 10.2684( 5), b = 4.0737(2), c = 7.8456(4) Å, β = 111.125(1)°, wR2 = 0.0572) consists of distorted Pd 4 Cl 4 octagons in chair arrange-ment to which four distorted Pd 2 Cl 2 squares are annulated on every second edge. In this arrangement each of the two Pd atoms of the squares are connected to one NÀ O group, bonded alternatively up and down to the Pd atoms with a PdÀ NÀ O angle of 129°. Such a square has the composition of the dimer which was found in the mass spectrum at 343.6 m/e. The octagons with four squares are interconnected to corrugated layers in the b-c-plane as a two-dimensional polymer.

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The advantages of microflow reactors have proven to be manifold, e.g., the excellent cooling ability, which allows performing exothermic reactions like nitrations safely. A critical point remains the transition from gram scale to industrial production. On an industrial scale, they are often designed for specific syntheses and are therefore less useful for a conventional research laboratory. A reactor setup was successfully developed mitigating these shortcomings and allowing the use of highly corrosive materials, like fuming inorganic acids (e.g., nitric, sulfuric acid), bases (e.g., bleach solutions), and chlorinated solvents. As a proof of functionality, the synthesis of nitroguanidine has been performed on a lab scale and was significantly improved over reported batch syntheses in terms of safety and production rate. A scale-up to industrial scale has hence become feasible.