Electron spin resonance studies of irradiated nitrous oxide

The γ-radiolysis of N 2 O at 77 °K, or vapor phase irradiation with 1 MeV He + ions followed by condensation at 77 °K, results in the formation and trapping of at least 4 paramagnetic species. Using isotopically labelled N 2 O these are identified as N 2 O + , NO 2 , NO 3 , and N. The latter assignment is reasonable on spectroscopic grounds but since this species arises exclusively from the central nitrogen of N 2 O it is difficult to describe its formation from established chemical reactions. The addition of H 2 O to the vapor phase experiments resulted in the trapping of O 2 − , while the addition of tetranitromethane or NO indicated the existence of O 2 − and O atoms, respectively. Possible reaction mechanisms are indicated.