Theoretical study of the structures and properties of cyclic nitramines: Tetranitrotetraazadecalin (TNAD) and its isomers

Density Functional Theory (DFT) was employed to study the geometries, electronic structures, infrared vibrational spectra, and thermodynamic properties of seven isomeric cyclic nitramines of C6H10N8O8 (i.e., TNAD and its six isomers) at the B3LYP/6-31G* level of theory. The experimental results available for TNAD were used to determine the reliability of the DFT method for generating structural and IR spectroscopic values for these molecular systems. The relative stabilities of the conformers were evaluated from the energy differences of the structures. Detonation properties of various conformers were evaluated using the Kamlet-Jacobs equations, and it was found that all the calculated results are comparable to the available experimental data. In addition, the calculated results demonstrate that all title compounds can be used as excellent propellant ingredients. (c) 2005 Wiley Periodicals, Inc.