Synthesis and Properties of N7O+ (PREPRINT)
Journal article preprint
AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
Pagination or Media Count:
The reaction of NOF2SbF6- with an equimolar amount of HN3 in anhydrous HF solution at -45 degrees Celsius produces N3NOFSbF6-. When an excess of HN3 is used in this reaction, N7OSbF6- is formed. However, this compound could not be isolated as a solid and rapidly decomposed in a quantitative manner with N2O evolution to N5SbF6-. This reaction represents a novel and more convenient synthesis for N5SbF6- because NOF2SbF6- is more readily accessible than N2FSbF6- and the N5 can be labeled in all five positions with 15N by the simple use of terminally singly-labeled N3-. The formation of the N7O cation was established by isotopic labeling experiments and theoretical calculations. It is shown that the addition of a second azido ligand to the same central atom allows attack of the negatively charged N-alpha atom of one ligand by the positively charged N-gamma atom of the second ligand, thereby greatly lowering the activation energy barrier towards decomposition and explaining why geminal diazides are much less stable than either mono-azides or vicinal di-azides.
- Inorganic Chemistry
- Physical Chemistry
- Atomic and Molecular Physics and Spectroscopy