THEORETICAL-STUDY ON PYROLYSIS AND SENSITIVITY OF ENERGETIC COMPOUNDS.2. NITRO-DERIVATIVES OF BENZENE

The UHF-SCF-AM1 method has been employed to study the pyrolysis mechan ism and impact sensitivity of nitro derivatives of benzene. Potential energy curves, transition states and activation energies of seven pyro lysis initiation reactions (homolysis of C-NO2 bond into radicals) hav e been obtained here first. The molecular geometries of reactants, tra nsition states and products of the seven reactions were fully optimize d. It is found that there is a good linear relationship between the ac tivation energies and bond orders of the weakest bond C-NO2 in the mol ecule of each reactant. The linear correlation coefficient is 0.996. T his result gives ''the principle of the smallest bond order'' powerful support and shows that the activation energy can also be used as a dy namic criterion of impact sensitivity.