A B3LYP and MP2(full) theoretical investigation into explosive sensitivity upon the formation of the molecule–cation interaction between the nitro group of RNO2 (R = –CH3, –NH2, –OCH3) and Na+, Mg2+ or Al3+

The changes of the bond dissociation energy of the trigger bond (C–NO2, N–NO2 or O–NO2) and nitro group charge upon the formation of the molecule-cation interaction between the nitro group of RNO2 (R = –CH3, –NH2, –OCH3) and cation (Na+, Mg2+, Al3+) have been systematically investigated using the B3LYP and MP2(full) methods with the 6-311++G**, 6-311++G(2d,p) and aug-cc-pVTZ basis sets. The trigger bond dissociation energy is the order of NM⋯Na+ < NM⋯Mg2+ < NM⋯Al3+, NA⋯Na+ < NA⋯Mg2+ < NA⋯Al3+ and MN⋯Na+ < MN⋯Mg2+, respectively. The strength of the trigger bond is enhanced and the explosive sensitivity is reduced upon the formation of molecule-cation interaction. The increment of the trigger bond dissociation energy (ΔBDE) in comparison with the monomer correlates well with the molecule-cation interaction energy Eint., electron density ρBCP(O6⋯cation), delocalization energy E LP ( O 6 ( s ) ) → LP ( cation ) ∗ ( 2 ) and mulliken charge of the nitro group. The linear relationship between the mulliken charge of the nitro group in complex and the O6⋯cation distance or E LP ( O 6 ( s ) ) → LP ( cation ) ( 2 ) is also found. The analyzes of AIM, NBO and electron density shifts show that the electron density shifts toward the trigger bond upon the formation of the molecule-cation interaction. Thus, the trigger bond is strengthened and the sensitivity is reduced.