Molecular Design of New Energetic Materials: Calculation of Performances and Thermal Stability

摘要

New energetic materials must combine high performance with lowrnvulnerability. We apply a predictive approach at the molecular level to identifyrnthe best candidate compounds satisfying required specifications.rnPerformances depend on density and formation enthalpy. To predictrndensity, we apply a group contribution method. Solid-state formation enthalpies,rn△_fH°(sol), are obtained from the difference between gas phase values, △_fH°(gas),rnand sublimation enthalpies, △_(sub)H°. To estimate △_fH°(gas), we apply either thernPIMM force field or Density Functional Theory techniques (DFT), depending onrnthe required accuracy. To estimate △_(sub)H°, we use an explicit expression tornrepresent the involved molecular factors. The discrepancy between observed andrncalculated values of △_fH°(sol) meets the accuracy required for thermochemicalrncalculations. Vulnerability includes thermal stability. Prediction of this property isrna complex problem and in a preliminary attempt, we correlated experimentalrndecomposition temperature with a dissociation energy calculated in the PM3rnsemi-empirical approach.