Vibrational frequency assignments of isotopically different forms of nitrate ion in ionic nitrate crystals

Abstract

Infrared and Raman spectra of powdered ionic nitrates contain low intensity vibrational bands which are assigned to isotopically different species. Bands at ~(ν1 − 20) and ~ (ν4 − 13) cm−1 are assigned to the 14N16O218O− ion whereas the band at ~ (ν2 − 20) cm−1 is assigned to the 15N16O3− ion. Failure of the ratio of band intensities to agree with predicted isotopic ratios is discussed.