Resonance Raman intensities show that methoxy substitution induces considerable allowed character to the La transition of benzene. In symmetric 1,3,5-trisubstituted benzene derivatives the induced allowed character should cancel by symmetry. However, in 1,3,5-trimethoxybenzene the resonance Raman spectrum shows a strong fundamental transition of v8, the clear signature of an allowed transition. It is shown that this is due to the presence of a C conformer of 1,3,5-trimethoxybenzene in which one of the three methoxy groups is rotated relative to the other two. This is supported by ab initio calculations of conformational energy, induced transition moment and the splitting of the v8 band.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Raman Spectroscopy|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Materials Science(all)