On the Comparison of Small Nitrogen and Phosphorus Oxide Cages
Abstract
Ab initio electronic structure calculations, including a natural bond orbital (NBO) analysis, are employed to compare the stabilities of larger nitrogen oxide cages and phosphorus oxide cages relative to the cage compound c‐N2O3 , which has been previously investigated as a potential energetic oxidizer. The larger NO cages, c‐N2O6 and c‐N4O6 exhibit less internal strain but have significantly lower barriers to decomposition of 1.9 kJ mol−1 and 5.6 kJ mol−1 respectively, compared to 37.6 kJ mol−1 for c‐N2O3, at the MP2/aug‐cc‐pVDZ level of theory. In contrast, the phosphorus oxide cage c‐P2O3 exhibits similar internal strain but has a significantly larger barrier to decomposition of 40.2 kJ mol−1 compared to the 24.4 kJ mol−1 of c‐N2O3 at CCSD(T)/CBS(Q‐5). Furthermore, NBO analysis shows that the PO bond is more ionic in nature compared to the NO bond. The reduced degree of ionic character leads to the kinetic instability of the nitrogen oxide cages and therefore renders them impractical as energetic oxidizers.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 14, 2015
- Source ID
- 10.1002/prep.201500227
Entities
People
- Jerry A. Boatz
- Robert J. Buszek
Organizations
- Air Force Office of Scientific Research