A new look on the electric spark sensitivity of nitramines

摘要

Electric spark energy,E_(ES),for a 50%probability of initiation of the 14 nitramines was determined using a measuring instrument in which the electrodes are in direct contact with the sample.Indirectly proportional relationships were established between the logarithm of the E_(ES)values and the length of the longest N-N bond in the nitramine molecule.This finding is compatible with the mechanism of the first step in the electro-reduction of the nitramine grouping.Directly proportional relationships were found to exist between the E_(ES)values and the crystal lattice free volumes,ΔV(i.e.an increase in theΔV values increases the nitramine's resistance to electric sparks)but there were several nitramines with the opposite course of this relationship.Also a semilogarithic relationships between the E_(ES)values and a ratio of intrinsic volumes of molecule,V_(int),to theΔV values were described as well as ambiguous linear dependence between these energies and a sum of the positive and negative extremes of the molecular surface electrostatic potentials,V_(S,∑).Several nitramines studied(always the same ones)display roughly the same distribution in the coordinate systems of relationships with lengths of the longest N-N bonds,the Vint/ΔV ratio and the sum V_(S,∑)as the independent variables.It was found that,typically,such relationships start from a single identical point,in effect a point corresponding to data for a structural unit from which tho studied nitramines can be hypothetically generated,and/or are converging on another point,often the one corresponding to the data for HNIW.All the findings point to a fundamental influence of the intermolecular forces on reactivity of nitramines exposed to electric sparks.