Knowledge Bank

The infrared spectra of fluorine nitrate $(FONO2)$ and chlorine nitrate $(ClONO2)$, including those of the nitrogen-15 isotopic compounds, have been obtained in the gas and solid phases. The far infrared spectra of the nitrogen-14 compounds in the gas phase were also examined, but only the torsional frequency at $152cm-1$ of the fluoride was observed. The barrier to internal rotation of the FO-group was calculated to be 10.2 kcal/mole, which is slightly greater than that in nitric acid. The present work showed that previous assignments of the fundamentals of these molecules must be revised, and the new assignments will be discussed.