The covalently bound N3O2 molecule: Two possible isomers

Density functional theory has been applied to investigate the possibility of the existence of the neutral N3O2 molecule. Two isomers (cyclic and open ONNNO) are found to be minima on the potential energy hypersurface at the local level of theory. The cyclic structure represents a minimum with the nonlocal functionals as well, while the open form is predicted to be a transition state with one of the applied nonlocal functionals. The open isomer lies about 20 kcal/mol lower in energy than the cyclic molecule, but both isomers are thermodynamically unstable with respect to NO + N2O and N2 + NO2. The calculated equilibrium geometries, vibrational frequencies and bond orders suggest that both isomers are covalently bound structures.