(65g) Quantum Chemical Characterization of Candidate Insensitive High Energetic Materials

In recent years, much effort has been put into the development of high performance insensitive munitions (IM). Such materials exhibit high thermal stability, resistance to impact, and high energetic performance [1]. Development of these materials has offered a challenge due to the tendency for IM compounds to exhibit poorer energetic performance in comparison to the traditionally used, higher sensitivity materials such as RDX and TNT [2,3].

In earlier times, when looking for novel energetic materials to meet these criteria, chemicals would be synthesized in a trial-and-error fashion under the hope that the product would meet the newly set standards [4]. This approach has proved to be expensive in both time and resources, and thus the need for a new method arose.

In this work, we perform quantum chemical analysis on candidate IM compounds Dinitropyrazole (DNP), Nitrotriazolone (NTO), 1-methyl-2,4,5-trinitroimidazole (MTNI) to determine heats of formation in the solid, liquid, and vapor phase, heat of sublimation, heat of vaporization, and torsional barriers. From this information we are able to quantify the strength of intramolecular interactions and gain insight into the impetus of these materials. Calculations for heats of formation, vaporization, and sublimation are performed using two different atom equivalent methods described by B. M. Rice and E. F. C. Byrd et. al. [5,6]. Torsional Barriers are calculated at HF, Density functional, and MP2 levels of theory using the 6-31+G(d,p) basis set.

[1] Davies, P. K.; Provatas, A. Weapons Systems Division, DTSO Defense and Science Technology Oranization 2006 Australia

[2] Huynh, M. H. V. ; Hiskey, M. A. ; Chavez, D. E. ; Naud, D. L. ; Gilardi, R. D. JACS 2005, 127, 12537.

[3]Wallace, L ; Cronin, M. P. ; Day, A. I. ; Buck, D. O. Environ, Sci. Technol. 2009, 43, 1993

[4]Rice, B. M. ; Hare, J. J. J. Phys. Chem. A 2002 106, 1770

[5]Rice, B. M. ; Pai, S. V. ; Hare, J. J. Comb. Flame 1999 118, 445

[6]Byrd, E. F. C. ; Rice, B. M. J. Phys. Chem A 2006 110, 1005