Propellants Explosives Pyrotechnics, Vol.31, No.5, 361-368, 2006
Calculation of detonation velocity, pressure, and electric sensitivity of nitro arenes based on quantum chemistry
The DFT-133LYP method, with basis set 6-31G*, is employed to optimize molecular geometries and electronic structures of thirty-nine nitro arenes. The averaged molar volume (V) and theoretical density (rho) are estimated using the Monte-Carlo method, based on 0.001 elections/bohr(3) density space and a self-compiled program. The detonation velocity (D) and pressure (P) of the explosives are estimated by using the Kamlet - Jacbos equation on the basis of the theoretical density and heat of formation (Delta H-f), which is calculated using the PM3 method. ne reliability of this theoretical method and results are tested by comparing the theoretical values of rho and D with the experimental or referenced values. The theoretical values of D and P are correlated with the experimental values of electric sensitivity (Ess). It is found that, for the nitro arenes, there is a linear relationship between the square of detonation velocity (D-2) or detonation pressure (P) and electric sensitivity (E-ES), which suggests that such a theoretical approach can be used to predict or judge the magnitude of E,, which is difficult to measure in the molecular design of energetic materials. In addition, we have discussed the influence of the substituted groups and the parameters of the electronic structure on density, detonation velocity, pressure, and electric sensitivity, and have shown that the substituted groups have the effect of activity or insensitivity, and that the influence of Q-(NO2) and E-LUMO is important.
Keywords:nitro;arenes;density functional theory;detonation velocity and pressure;electric sensitivity