MEASUREMENT AND CALCULATION OF THE RAMAN OPTICAL-ACTIVITY OF ALPHA-PINENE AND TRANS-PINANE

Raman scattering and Raman optical activity (ROA) spectra of alpha-pin ene and trans-pinane were measured for both enantiomers. The experimen t was performed on a newly built, fully computer-controlled backscatte ring incident circular polarization ROA instrument. High-quality spect ra were obtained and interpreted on the basis of ab initio quantum che mical calculations. Excellent agreement between the calculated and obs erved spectra was observed in the mid IR region. An approximate distri buted origin gauge model for calculation of the polarization tensors w as proposed. The shapes of ROA spectra calculated with this model are similar to those obtained with conventional, computationally more dema nding ROA computations.