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nonsuperimposable

Objects that cannot perfectly overlap with each other

Chiral Center

Carbon atom that has 4 different attachments that make the compound lack symmetry

Achiral molecules

Any compound with any plane of symmetry

Enantiomers

nonsuperimposable mirror image of a chiral compund

switching any two groups on a chiral center will

invert the configuration

stereodescriptor

describes the 3D spatial arrangement of the atoms in the molecule

S

123 counterclockwise

R

123 clockwise

Optically active

Compounds that rotate the plane of plane polarized light

Chiral compounds are optically

active

Achiral compounds are optically

inactive

dextrorotatory

compound that gives a positive rotation

levorotatory

compound that gives a negative rotation

Diastereomers

Two compounds that aren’t mirror images of each other and nonsuperimposable

Optically/enantiomerically pure

The light rotations made by samples that have a single enantiomer

Racemic mixtures

1 to 1 mixture of enantiomers that are optically inactive

Atropisomers

Stereoisomers formed from compounds that can’t rotate around a bond and don’t have a chiral center

Allenes

Compounds that have 2 adjacent C=C bonds

Allenes and Atropisomers are chiral because

The whole compound lacks symmetry