THEORETICAL-STUDY OF THE BICYCLIC NITROGEN TETROXIDE CATION, NO4+

The structure and energy of the bicyclic nitrogen tetroxide cation, D- 2d NO4+, and its C-2v transition state for dissociation into NO2+ and O-2 have been studied theoretically by the coupled-cluster (CC) and si milarity-transformed equation-of-motion coupled-cluster methods (STEOM -CC). The computed 137 kcal/mol energy of decomposition and 370 kcal/m ol gas-phase heat of formation identify NO4+ as a highly energetic spe cies. Nevertheless, its low dissociation barrier (12-17 kcal/mol) and high vertical electron affinity (8.4 eV) indicate that NO4+ will have a low stability, which will complicate its experimental observation.