Problems and Approaches for Estimating the Enthalpy of Formation of Energetic Materials

Approaches for estimating the enthalpy of formation of neutral energetic molecules as well as of energetic 1:1 salts were critically evaluated. The effectiveness of using the Trouton rule to obtain the enthalpy of sublimation of neutral energetic material (EM) molecules was compared with the values obtained using the program RoseBoom©, and the estimated values were compared with experimental enthalpy of sublimation values available for energetic molecules. Specific problems associated with estimating the enthalpy of formation for energetic salts were also investigated for 1:1 salts, namely calculation of the enthalpy of formation of the constituent ions in the gasphase, as well as estimation of the lattice enthalpy for these salts. Using experimentally determined values, the lattice potential energy was estimated, and compared to the values calculated using both the Jenkins and Gutowski equations. Furthermore, the enthalpies of formation of several salts were calculated and compared to experimentally determined values (combustion calorimetry) from the literature. Finally, these values were compared to the ones obtained using methods based on the enthalpy of salt reaction described by Sinditskii in the literature.