Gas-phase electron paramagnetic resonance absorption in a N16O, N17O, and N18O mixture

The X-band EPR spectra of a gaseous mixture of 14N16O, 14N17O, and 14N18O are presented. Statistically significant differences in the spectra indicate that a unified theory of isotopic effects is derivable from the data. Further interpretation will be presented in a second paper. The oxygen-17 hyperfine interaction was found to be ≈ 57.4 G and a large oxygen-17 quadrupole interaction is indicated. The s character of the 2pπ electron on oxygen in nitric oxide is estimated to be 2.0%, in good agreement with that estimated for the isoelectronic molecule O2−17.