Organic Chemistry

Conformations

Different spatial arrangements of a molecule that result from rotation around single sigma bonds.

Staggered conformation

Lower energy and more stable arrangement of atoms in a molecule.

Eclipsed conformation

Higher energy and less stable arrangement of atoms in a molecule.

Chair conformation

Most stable conformation of cyclohexane.

Axial orientation

Position of a substituent in cyclohexane that is oriented vertically.

Equatorial orientation

Position of a substituent in cyclohexane that is oriented horizontally.

Conformers

Same molecule that differs in angle about one or more sigma bonds.

Isomers

Compounds with the same molecular formula but different structures or connectivity.

Constitutional isomers

Isomers with the same molecular formula but different connectivity and names.

Stereoisomers

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

Cis isomer

Isomer where substituents are on the same side of a double bond or a cyclic structure.

Trans isomer

Isomer where substituents are on opposite sides of a double bond or a cyclic structure.

Z isomer

Stereoisomer where both high priority substituents are on the same side.

E isomer

Stereoisomer where high priority substituents are on opposite sides.

Cahn-Ingold-Prelog Rules

Rules used to assign priority to substituents when determining stereochemistry.

Enantiomers

Optical isomers that are non-superimposable mirror images of each other.

Optically active

Substance that rotates the plane of polarized light.

Racemic mixture

A mixture containing equal parts of + and - enantiomers, resulting in no optical activity.

Diastereoisomers

Stereoisomers that are not mirror images of each other and differ in configuration.

Meso compound

A compound that has multiple stereocenters but is superimposable on its mirror image, making it optically inactive.

Chiral center

A carbon atom that is bonded to four different groups, leading to optical activity.