Isomers

Types

• Structural Isomers
• Stereoisomers / Spatial Isomers
  • Enantiomers / Optical Isomers
  • Diastereomers
    • Meso Isomers (not Mesomers)
    • Cis/Trans Isomers
    • E-Z Isomers
    • Non-enantiometric optical isomers
• Isotopes

Molecular Chirality

Definition:
A chiral molecule is a type of molecule that has a non-superposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom.

Enantiomers:
Two mirror images of a chiral molecule are called enantiomers or optical isomers.

Dextrorotatory, Laevorotatory:
Pairs of enantiomers are often designated as "right-", "left-handed" or, if they have no bias, "achiral". As polarized light passes through a chiral molecule, the plane of polarization, when viewed along the axis toward the source, will be rotated clockwise (to the right) or anticlockwise (to the left). A right handed rotation is dextrorotary (d); that to the left is levorotary (l). The d- and l-isomers are the same compound but are called enantiomers.

Racemic Mixtures (Equal Mixtures of D- and L-)
An equimolar mixture of the two optical isomers, which is called a racemic mixture, will produce no net rotation of polarized light as it passes through.

Applications:
It is studied for its application to stereochemistry in inorganic chemistry, organic chemistry, physical chemistry, biochemistry, and supramolecular chemistry.

More recent developments in chiral chemistry include the development of chiral inorganic nanoparticles that may have the similar tetrahedral geometry as chiral centers associated with sp3 carbon atoms traditionally associated with chiral compounds, but at larger scale. Helical and other symmetries of chiral nanomaterials were also obtained.