| Following steady development over the past two decades, the theory and measurement of Raman optical activity (ROA) have both reached a sophisticated level. This dissertation presents advances in ROA in the areas of artifact control, experimental measurements, theoretical intensity computation, isolation of pre-resonance behavior and observation of surfaced-enhanced phenomena.; Backscattering incident circular polarization (ICP) and in-phase dual circular polarization (DCP{dollar}sb{lcub}rm I{rcub}{dollar}) ROA have been demonstrated theoretically and experimentally to be the best configurations for routine ROA studies on biological molecules in the far-from-resonance limit. Since DCP{dollar}sb{lcub}rm I{rcub}{dollar} ROA provides better signal-to-noise ratios and artifact control when both methods are available on the same ROA instrument, backscattering DCP{dollar}sb{lcub}rm I{rcub}{dollar} ROA spectra were recorded for terpene molecules, (({dollar}-{dollar})-trans-pinane, ({dollar}-{dollar})-cis-myrtanylamine, ({dollar}-{dollar})- -pinene, ({dollar}-{dollar})- -pinene, (+)-nopinone, ({dollar}-{dollar})-verbenone, ({dollar}-{dollar})-myrtenol, ({dollar}-{dollar})-nopol, ({dollar}-{dollar})-myrtenal, ({dollar}-{dollar})-fenchone, (+)-limonene, and ({dollar}-{dollar})-carvone as neat liquids, and ({dollar}-{dollar})-camphor and ({dollar}-{dollar})-camphene in CCl{dollar}sb4{dollar}), ephedrine molecules, ((1S,2R)-ephedrine, (1S,2R)-norephedrine, (1S,2S)-pseudoephedrine and (1S,2S)-norpseudoephedrine in HCl aqueous solution), an amino acid, (L-alanine in H{dollar}sb2{dollar}O and D{dollar}sb2{dollar}O solution), four peptides, (glycyl-L-alanine, L-alanylglycine, L-alanyl-L-alanine and L-alanyl-L-alanyl-L-alanine in H{dollar}sb2{dollar}O and D{dollar}sb2{dollar}O solution), and two proteins, (lysozyme and albumin).; Theoretical Raman and ROA intensities for L-alanine, L-alanine-2-d{dollar}sb1{dollar} and L-alanine-3,3,3-d{dollar}sb3{dollar} in H{dollar}sb2{dollar}O and D{dollar}sb2{dollar}O solution were calculated by using ab initio methods with a 6-31G* basis set. A self-consistent-field calculation with the inclusion of an Onsager reaction field to simulate solvent effects was found necessary to stabilize properly the zwitterionic form of alanine. A high level of agreement was found between experiment and calculation for both Raman and ROA spectra.; By comparing backscattering ICP and DCP{dollar}sb{lcub}rm I{rcub}{dollar} ROA and right-angle ICP and scattered circular polarization (SCP) ROA spectra, pre-resonance ROA behavior was observed. The gradual breakdown of the far-from-resonance approximation was observed by comparing ROA spectra for ({dollar}-{dollar})-trans-pinane, ({dollar}-{dollar})- -pinene, ({dollar}-{dollar})-verbenone and (+)-quinidine. The differences between backscattering ICP and DCP{dollar}sb{lcub}rm I{rcub}{dollar} ROA spectra also resulted in an indirect observation of out-of-phase dual circular polarization (DCP{dollar}sb{lcub}rm II{rcub}{dollar}) ROA signal.; Possible observation of surface-enhanced ROA phenomena for quinidine in an AgCl colloid is reported here for the first time. The experiment was carried out by using a backscattering DCP{dollar}sb{lcub}rm I{rcub}{dollar} ROA configuration. This may open a new frontier for ROA studies. |
