Stereochemistry: Chiral Molecules

These flashcards cover key concepts and vocabulary related to stereochemistry, particularly focusing on chirality, isomers, and their properties.

Chirality

The property of a molecule that makes it non-superimposable on its mirror image.

Chiral

An object that cannot be superimposed on its mirror image, like human hands.

Achiral

An object that is identical to its mirror image.

Isomers

Different compounds that have the same molecular formula.

Constitutional Isomers

Isomers with the same molecular formula but different connectivity of atoms.

Stereoisomers

Isomers that have the same connectivity but differ in the arrangement of atoms in space.

Enantiomers

Stereoisomers that are non-superposable mirror images of each other.

Diastereomers

Stereoisomers that are not mirror images of each other.

Chirality Center

A tetrahedral atom with four different groups attached, which creates a pair of enantiomers.

Specific Rotation

The degree to which a chiral compound rotates the plane of polarized light.

R,S System

A nomenclature system for enantiomers that assigns priorities to the groups attached to a chirality center.

R Configuration

Describes an enantiomer whose groups descend in priority in a clockwise direction.

S Configuration

Describes an enantiomer whose groups descend in priority in a counterclockwise direction.

Meso Compound

A compound that is achiral despite having chirality centers, due to a plane of symmetry.

Racemic Mixture

A 1:1 mixture of two enantiomers, resulting in no net optical rotation.

Optical Activity

The ability of a chiral substance to rotate plane-polarized light.

Enantiomeric Excess (ee)

A measure of the purity of an enantiomer in a mixture, calculated from optical rotation.

Fischer Projection

A two-dimensional representation of chiral molecules where vertical lines represent bonds projecting behind the plane of paper.

Cahn-Ingold-Prelog System

A systematic way to assign priority to the substituents attached to a chiral center based on atomic numbers.