Resonance Raman spectrum of the permanganate ion in different host lattices

Abstract

Resonance Raman studies of different salts of the [MnO₄]^– ion by irradiation within the contour of the lowest ¹T₂â†�¹A₁ band indicate that although the value of x₁₁(–1.1 ± 0.2 cm^–1) is not significantly affected by the counterion, that of ω₁ decreases (from ca. 849 to ca. 836 cm^–1) as the size of the host lattice increases. For the [Ph₄P]⁺ salt, the full-width at half-maxima of the members of the v₁ν₁ progression bear a simple linear relationship to v² ₁, as expected if they were to depend on an increase in vibrational relaxation and dephasing times. Involvement of ν₃ in resonance Raman progressions of the sort v₁ν₁+ν₃ indicates a Jahn–Teller distortion along the normal coordinate Q₃ in the ¹T₂ excited state.