Nitrosylazide

• Tetra nitric oxide
• Tetrastickstoffoxid

Pale yellow solid

-60 ° C to -55 ° C.

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Nitrosylazid ( tetra nitric oxide ) is an unstable nitric oxide, which can be seen both as an inorganic azide and covalent Nitrosylverbindung. The nitrogen content in the molecule is 77.79 %.

Representation and extraction

The first preparation was described in 1958. They are prepared by the reaction of sodium azide with nitrosyl chloride at a temperature below -50 ° C. The product is obtained by vacuum distillation from the reaction mixture.

Instead of nitrosyl chloride may also be used as a source of NO and Nitrosylhydrogensulfat and nitrous acid.

Properties

Nitrosylazid can be obtained below -50 ° C as a pale yellow solid. The melting point is given in the range of -60 ° C to -55 ° C. The vapor pressure function is given by August according lg ( P) = -A / T B (P in Torr, T in K) with A = 1215.6 and B = 7.306. By extrapolating a normal pressure boiling point of 1.5 ° C can be estimated. This can not be achieved in practice, because the compound decomposes above -50 ° C in nitrogen and nitrous oxide. A quantum chemical ab initio calculation showed a strongly exothermic reaction heat with -381 kJ · mol -1 for the decay.

A characterization was carried out by means of infrared and Raman spectroscopy, the measured bands agree well with calculated values ​​for a trans - chain structure. Quantum chemical calculations showed a higher energy of 4.2 kJ · mol -1 cis- chain form, as well as a more stable by 54.4 kJ · mol -1 aromatic 6π - ring shape. For the cyclization reaction would have to be applied due to the bending of the azide function a very high activation energy of 205 kJ · mol -1. Which can be seen as a reason that the Nitrosylazid is stable and can be isolated at low temperatures. The cyclic form disintegrates quickly in nitrous oxide and nitrogen.