RAMAN SPECTRA OF SOME NEGATIVE MOLECULAR IONS DOPED IN ALKALI HALIDE CRYSTALS

Author Institution: Division of Pure Chemistry, National Research Council of CanadaThe Argon ion laser was used to obtain vibrational spectra of $O^{-}_{2}, N^{-}_{2}, S^{-}_{2}$ and $S^{-}_{3}$ at concentrations of about $10^{-4}$ to $10^{-3}$ mole ratio in some alkali halide single crystals. For the diatomic species a simple relation holds for the change of the vibrational frequency with the lattice constant in a series of crystals with common cation. The spectrum of the $S^{-}_{3}$ ion, shows a pronounced resonance Raman effect permitting the 5th harmonic of the fundamental to be observed in some crystals