Improved reliable approach to predict melting points of energetic compounds

A new general method has been introduced for prediction of melting points of important classes of energetic compounds including polynitro arene, polynitro heteroarene, acyclic and cyclic nitramine, nitrate ester and nitroaliphatic compounds. It extends earlier works, which were used for certain classes of energetic compounds, to estimate melting points of any compound containing at least one of the groups Ar–NO2, C–NO2, C–ONO2 or N–NO2 through additive and non-additive functions. Elemental composition of an energetic compound of composition CxHyNvOw was used as additive function. The methodology assumes that non-additive function of desired compound can be approximated as the difference between the positive and negative contributions of specific structural moieties. The new model is applied for 149 different energetic compounds including complex molecular structures. For those energetic compounds where one of well-developed group additivity methods can be applied, it is shown that average deviation of the new method is much lower. The new method also gives better predictions as compared to another new and suitable model, which is based on division of the calculated enthalpy of melting to entropy of melting.