Solvent Effect on Optical Rotation:A Case Study of Methyloxirane in Water

摘要

A long-standing challenge in molecular stereochemistry is to assess the contributions of the solvent surrounding chiral organic molecules.The observed specific rotation angles and optical rotatory dispersion (ORD) spectra are strongly influenced by solvent-solute interactions.For example,(S)-methyloxirane has a positive optical rotation (OR) in water and a negative OR in benzene.The vapor phase and condensed phase optical rotations of chiral molecules are also known to differ in large and nonintuitive ways.Access to experimental gas phase optical rotation data and to modern linear-response OR calculations provides the tools needed to analyze and predict the contributions of solute-solvent interactions to OR.Wilson et al.recently reported the OR for a series of organic molecules in the vapor phase using cavity ring-down polarimetry.