Isomers {stereoisomer}| {optical isomer} can have right-handed and left-handed structures that single-bond four different substituents to carbon atom. Stereoisomers are asymmetric molecules, such as enantiomer, racemic, diastereomer, and meso compound. The D and L system {glyceraldehyde} designates stereoisomers relative to (+)-glyceraldehyde {D-glyceraldehyde} and (-)-glyceraldehyde {L-glyceraldehyde}.
For R-S systems {Cahn-Ingold-Prelog system} {CIP system}, at asymmetric carbon atom, place lowest-atomic-number bound atom straight-behind the plane, with the three other atoms facing observer. Mark highest-atomic-number atom and next highest. For atoms with same atomic number, use atomic mass. If two or more atoms are the same, go outward from chiral atom, applying same rules to farther atoms. Double bonds, triple bonds, and aromatic rings are like two or three bonds with atoms. If highest to next highest goes clockwise, compound is R or Rectus. If highest to next highest goes counterclockwise, compound is S or Sinister.
Isomers {meso compound}| have asymmetric carbon but also have symmetry plane that cancels optical rotation.
Two isomers {enantiomer}| {enantiomorph} can be mirror images.
Mixtures {racemic mixture} can have equal enantiomer amounts.
Reactions {racemization}| can change one enantiomer into the other.
Stereoisomers can rotate plane-polarized light clockwise {dextrorotatory} (+), as measured by degrees in polarimeter.
Stereoisomers can rotate plane-polarized light counterclockwise {levorotatory} (-), as measured by degrees in polarimeter.
5-Chemistry-Organic-Bond Orientation-Isomer
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225