Theoretical Investigation of the Relationship between Impact Sensitivity and the Charges of the Nitro Group in Nitro Compounds

ABSTRACT By means of density functional theory (DFT), the general gradient approximation method (GGA), and the Beck LYP hybrid functional and DNP basis set, nitro group Mulliken charges (Q NO 2 ) are calculated and defined to assess and correlate with the impact sensitivities (H 50 ) of nitro compounds: very negative Q NO 2 and high H 50 . By calculating, analyzing, and comparing, we find that Q NO 2 can be regarded as a structural parameter to estimate impact sensitivity and has more availability in almost all nitro compounds in contrast to the length of the C‒NO 2, N‒NO 2 , or O‒NO 2 bond R R ‒ NO 2 , molecular electrostatic potential (V mid ), and oxygen balance (OB). At the same time, it has good reliability and accuracy even though there are some exceptions. According to the data in this paper, the compound may be sensitive (H 50 ≤ 0.4 m) when its nitro group has fewer negative charges than about 0.23.