Optical isomerism

Optical isomerism is a form of isomerism (specifically stereoisomerism) whereby the different 2 isomers are the same in every way except being non-superposable mirror images1 of each other. Optical isomers are known as chiral molecules (prounounced ki-rall) .

Related Topics:
Isomerism - Stereoisomerism - Mirror image - 1 - Chiral

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The (-)-form of an optical isomer rotates the plane of polarization of a beam of polarized light that passes through a quantity of the material in solution counterclockwise , the (+)-form clockwise. It is due to this property that it was discovered and from which it derives the name optical. The property was first observed by Louis Pasteur in 1848 in racemic acid.

Related Topics:
Rotates - Polarization - Light - Solution - Counterclockwise - Clockwise - Optical - Louis Pasteur - 1848 - Racemic acid

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The study of optical isomerism is now called stereochemistry. Optical isomers are often called stereoisomers (in fact, stereoisomers constitute a more general group, since stereoisomerism needn't necessarily imply optical activity).

Related Topics:
Stereochemistry - Optical activity

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Two types of molecules which differ only in their relative stereochemistry

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are said to be enantiomers of each other. A mixture of equal amounts

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of both enantiomers is said to be a racemic mixture.

Related Topics:
Enantiomer - Racemic

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This form of isomerism can arise when an atom (usually carbon) is surrounded by four different functional groups. Swapping two of the groups can arise in two different molecules - mirror images of each other.

Related Topics:
Carbon - Functional groups - Molecules

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A rule of thumb for determining the isomeric form (usually called D- and L-)2 of an amino acid, is the "CORN" rule. The groups:

Related Topics:
2 - Amino acid

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COOH, R, NH2 and H (where R is an unnamed carbon chain)

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