Polarized Infrared Spectrum of Sodium Nitrite

Abstract

The infrared spectra of single crystals of NaNO₂ were obtained in polarized light. The polarization behavior of the strong absorptions leads to the following assignment of the nitrite fundamentals ν₁ = 1325 cm⁻¹, ν₂ = 831 cm⁻¹, and ν₃ = 1360 cm⁻¹. Other bands of lower intensity are observed. A combination band (ν₁+ν₂) at 2670 cm⁻¹ shows a polarization behavior in accord with site group selection rules. An effect is discussed which results from the use of an infrared microscope in the investigation of polarization spectra.