Raman optical activity, quantitation

Vitalis and Pappu have applied experimental /hohp couplings for dipeptides as one of the tests to assess the validity of the ABSINTH model, their new continuum solvation model for simulations of polypeptide structures in aqueous solutions. Theoretical and experimental vicinal proton-proton couplings have been found by Bouo and co-workers to be quantitatively consistent with the Raman optical activity of four proline containing model dipeptides. 

Qu X, Lee E, Yu G-S, Freedmann TB and Nafie LA (1996) Quantitative comparison of experimental infrared and Raman optical activity spectra. Applied Spectroscopy 50 649-657. 

Raman spectroscopy is one of the optical molecular spectroscopic techniques capable of giving quantitative information about molecular orientation in polymers. A resonant Raman-active agent and/or highly anisotropic rigid rod polymeric substance incorporated into polymers can be easily detected at low concentration levels and used as an indicator of the molecular orientation of the processed polymer itself [425]. It is possible to apply resonance Raman spectroscopy to many more problems. The combined application of UV/VIS and near-IR Raman excitation may be advantageous. UV excitation selects for a small number of resonance-enhanced bands of an analyte and the measurements are made with high sensitivity and selectivity. In contrast, with non-resonance visible and near-IR excitation, numerous Raman bands occur with similar intensities for all components in the sample in proportion to their concentrations. Consequently, one obtains both average and specific information on sample composition [419]. 

---