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.