Nitramino group, structure

Fig. 1. Structure of the nitramino group, with dimethylnitramine as an example...

No analogous relationships between Edr values and NMR chemical shifts, Sn, of nitro-group nitrogen atoms were found [97], due to less correlation of the shifts with structural details. It must be stated that the aza (amino) nitrogen chemical shifts, Sa, in the nitramino groups are expected to be influenced by the nitrogen hybridisation, the size and conformation of molecule. 

Fig. 12. A cattergram display of the amino C-N C bond angle and the amino bend (in degrees, see Fig. 6 for definition) of the nitramino group, as observed in more than 60 X-ray structural determinations. The curved line represents the best fit to the data by a second-degree polynomial function.

The nomenclature of nitroaminotetrazoles (also referred to as nitramino-or nitriminotetrazoles) is usually inconsistent in literature [52] as a result of incomplete characterization of the previously reported compounds. Therefore, a complete characterization of three well-known nitroaminotetrazoles is given in this chapter (see also [53]). The crystal structures show the first examples of neutral 5-aminotetrazoles that have been nitrated at the primary NH2 group. For 5-nitroaminotetrazole only the cell parameters have been previously pubhshed [54], while several examples of 5-methyl-nitraminotetrazoles have been structurally characterized and reported in the literature [55]. On the basis of the crystal structures obtained, the nitration product of 5-aminotetrazole (1) is now referred to as 5-nitriminotetrazole (2). 

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