Polarized Vibrational Spectra of Potassium Chlorate

Abstract

The Raman spectra of single crystal KClO₃ were measured in the region above 30 cm⁻¹ at 298 and 77°K. Single crystal infrared spectra in the internal mode region were measured by reflection at 298°K. Infrared spectra of the polycrystalline material also were measured at 77°K. Assignments for all of the crystal vibrations that are derived from correlation field splitting of the (internal) ClO₃⁻ vibrations were made from the results of the polarization measurements. Longitudinal optical mode frequencies for the ${\nu }_3{\mathrm{(B}}_u)$ and ${\nu }_3{\mathrm{(A}}_u)$ components obtained from polarized (infrared) specular reflection measurements on polycrystalline KClO₃ are also reported. The bands due to the Raman active lattice modes were observed in the region below 200 cm⁻¹ and were tentatively assigned to librational or to translatory‐type motions. The 2‐cm⁻¹ splitting observed for the ${\nu }_1$ mode of the ³⁵Cl¹⁸O¹⁶O₂ and ³⁷Cl¹⁸O¹⁶O₂ isotopes in the low‐temperature Raman spectra was assigned to an orientational effect in the lattice.