The main goal of the presented thesis is a theoretical study of heat of formation for high-nitrogen energetic materials. A modification of the classical approach to the isodesmic reactions is realized with the intent that molecules on both sides of the corresponding equation have not only the same number of atoms but also approximately the same size and skeletal similarity. This approach is designated as a method "Alternative Isodesmic Reaction (AIR method)". At its base, using the DFT B3LYP / cc-pVTZ and B3PW91 / cc-pVTZ, for the high nitrogen heterocycles, which are selected from the group of triazoles, triazines, tetrazines, the enthalpy of formation values the gaseous phase f H°(298,g), were obtained whose values are close to the published f H°(298,g). Their application in the calculation of the relevant characteristics of these heterocycles detonation gave real values.

The prediction of detonation properties of the new generation of high-nitrogen energetic materials (HNEM) is based on knowledge of their heats of formation, which are sum of values of particular nitrogen heterocyclic fragments. The diploma thesis describes theoretical calculations of heats of formation in gas phase ?f H°(298,g) for series of azines (number of N atoms 2-6) and azoles (number of N atoms 2-5) by means of quantum chemical methods. The semiempirical methods as PM3, DFT methods utilizing isodesmic approach and finally thermochemical G-recipes were used. All calculated values of heats of formation were scrutinized and for future application to HNEM materials the DFT B3LYP/cc-pVTZ method and thermochemical recipe T1 were recommended.