Premium
Evidence for short range orientation effects in pure liquid SO 2 from vibrational Raman spectroscopy
Author(s) -
Kamoun Mohamed
Publication year - 1979
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250080411
Subject(s) - raman spectroscopy , isotropy , anisotropy , molecule , dilution , wavenumber , chemistry , analytical chemistry (journal) , solvent , inert , range (aeronautics) , spectroscopy , orientation (vector space) , molecular physics , nuclear magnetic resonance , materials science , thermodynamics , optics , organic chemistry , physics , geometry , quantum mechanics , composite material , mathematics
In the Raman spectrum of pure liquid SO 2 a difference is observed between the wavenumbers of the isotropic and anisotropic components of the totally symmetric vibrations ν 1 and ν 2 , the anisotropic component being at a higher frequency than the isotropic one. The separations are Δν 1 = 5 cm −1 , Δν 2 ≃ 3.5 cm −1 . This effect is approximately independent of temperature in the range −60 to +40°C. It disappears with dilution of SO 2 in an inert solvent. The same shift is observed in solid SO 2 . Mirone and Fini 2 and Josien 3 have observed and interpreted such an effect in the case of larger molecules. They assume the liquid to be composed of clusters in which the molecules are partially ordered. In the case of SO 2 our calculations based on such a model are in good agreement with the experimental results for ν 2 but not for ν 1 .