Chemical Micro-Mechanism of Initiation by Impact

We were engaged in study of impact sensitivity, defined as the so-called first reactiori , in the past [6,75]. Recently we also have undertaken a study 

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. 

NMR chemical shifts, 51 , of the carbon atoms of aromatic system carrying the most reactive nitro groups (the numbers in brackets denote the positions in molecule). 

The same shape of relationship as shown in Fig. 3 is valid for polynitro arenes in Fig. 5 here the impact sensitivity detected by sound correlates with C NMR chemical shifts of the bearers of the most reactive nitro groups in the molecule. According to this diagram, nitro groups in 2-positions of the 

TNR and BITNT molecules and in 2- or 6-position of picryl group in the PYX molecule are found to be the most reactive. These groups are also most sterically crowded. 

---