A Quantum Chemical Theoretical Study of Decomposition Pathways of N9 (C2v) and N9+ (C2v) Clusters

Abstract

Dissociation pathways of N9 (C2v) and N9+ (C2v) clusters have been investigated by ab initio molecular orbital theory and density functional theory methods. The reactants and products involved were optimized at the HF/6-31G*, B3PW91/6-31G*, B3LYP/6-31G*, and MP2/6-31G* levels of theory. Transition states of decomposition processes were found and characterized on the HF/6-31G*, B3PW91/6-31G*, and B3LYP/6-31G* potential energy surfaces (PES). At the above levels, the barrier heights of the process N9 → N6 + N3, with zero point energy corrections, are predicted to be 15.3, 31.8, and 32.9 kcal/mol. Similarly, those of the second step N6 → 3N2 are 8.2, 16.3, and 14.4 kcal/mol. The barrier height of N9+ → N7+ + N2 is 2.1 kcal/mol, and that of second step N7+ → N2 + N5+ is 4.3 kcal/mol at the B3LYP/6-311+G*//B3LYP/6-31G* level. The potential applications of N9 and N9+ as high-energy density materials were examined.