Theoretical investigation on structure and properties of 2,4,5-trinitroimidazole and its three derivatives

Density functional theory has been used to investigate geometries, C-NO2 bond dissociation energies (BDEs), heats of formation (HOFs), and relative specific impulses (Is) of 2,4,5-trinitroimidazole and its three derivatives (1-methyl-2,4,5-trinitroimidazole (I), 1-carboethoxy-2,4,5-trinitroimidazole (II) and 1-picryl-2,4,5-trinitroimidazole (III)). The trigger linkage C-NO2 in process of detonation has been identified on basis of bond dissociation energies. Heats of formation in gas phase at 298 K are determined for the first time using working chemical reactions at B3LYP/6-311+G(3df,2p)//B3LYP/6-31G(d) level. The performance of our employed theoretical level and reactions for calculating HOFs is first verified to be accurate to within 1 kcal mol−1 by a test system. Then HOFs are computed to be 48.1, 52.2 ± 0.6, −35.7 ± 0.9 and 105.7 ± 0.7 kcal mol−1 for 2,4,5-trinitroimidazole, compounds I, II, and III, respectively. Based on the calculated values of HOFs and Is, we predict III to be a good candidate for high energy material.