Relationships for the Impact Sensitivities of Energetic C-Nitro Compounds Based on Bond Dissociation Energy

The ZPE-corrected C-NO2 bond dissociation energies (BDEsZPE) of a series of model C-vitro compounds and 26 energetic C-vitro compounds have been calculated using density functional theory methods. Computed results show that for C-vitro compounds the UB3LYP calculated BDEZPE is less than the UB3P86 using the 6-31G** basis set, and the UB3P86 BDEZPE changes slightly with the basis set varying from 6-31G** to 6-31++G**. For the series of model C-vitro compounds with different chemical skeletons, it is drawn from NBO analysis that the order of BDEZPE is not only in line with that of the NAO bond order but also with that of the energy gap between C-NO2 bonding and antibonding orbitals. It is found that for the energetic C-vitro compounds whose drop energies (Es-dr) are below 24.5 J a good linear correlation exists between E-dr and BDEZPE, implying that these compounds ignite through the C-NO2 dissociation mechanism. After excluding the so-called trinitrotoluene mechanism compounds, a polynomial correlation of In(E-dr) with the BDEZPE calculated at density functional theory levels has been established successfully for the 18 C-NO2 dissociation energetic C-vitro compounds.