Intramolecular Enantiomerism in S(+)2,2-dimethyl -1,3-dioxolane-4-methanol: The Interpretation of Raman Optical Activity Intensity.

A bond polarizability algorithm was developed and applied to interpret the Raman optical activity (ROA) intensity. It is demonstrated that for the chiral molecule such as S(+)2,2-dimethyl-1,3-dioxolane-4-methanol there exists approximate (or symmetry breaking) mirror reflection that reverses the signs of the differential bond polarizabilities of the pair bond coordinates that are related to each other by the mirror reflection, just like that between the right and left enantiomers. The magnitude difference of the differential bond polarizabilities of the pair bond coordinates becomes smaller as they are farther away from the asymmetric atom. Hence, that the asymmetric atom (center) plays a central role in ROA is confirmed from a spectroscopic viewpoint. Meanwhile, the concept of intramolecular enantiomerism is proposed.