Advices For Studying Organic Chemistry

5.7. PROPERTIES OF ENANTIOMERS: OPTICAL ACTIVITY

1. Enantiomers have identical physical properties such as boiling points, melting
   points, refractive indices, and solubilities in common solvents except optical
   rotations.

1. Many of these properties are dependent on the magnitude of the intermolecular
   forces operating between the molecules, and for molecules that are mirror
   images of each other these forces will be identical.


2. Enantiomers have identical infrared spectra, ultraviolet spectra, and NMR
   spectra if they are measured in achiral solvents.


3. Enantiomers have identical reaction rates with achiral reagents.

Table 5.1 Physical Properties of (R)- and (S)-2-Butanol

Physical Property (R)-2-Butanol (S)-2-Butanol

Boiling point (1 atm) 99.5 °C 99.5 °C

Density (g mL–1 at 20 °C) 0.808 0.808

Index of refraction (20 °C) 1.397 1.397

2. Enantiomers show different behavior only when they interact with other chiral
   substances.

1. Enantiomers show different rates of reaction toward other chiral molecules.


2. Enantiomers show different solubilities in chiral solvents that consist of a
   single enantiomer or an excess of a single enantiomer.

3. Enantiomers rotate the plane of plane-polarized light in equal amounts but in
   opposite directions.

1. Separate enantiomers are said to be optically active compounds.

5.7A PLANE-POLARIZED LIGHT

1. A beam of light consists of two mutually perpendicular oscillating fields: an