Axial chirality is a special case of chirality in which a molecule does not possess a stereogenic center (the most common form of chirality in organic compounds) but an axis of chirality – an axis about which a set of substituents is held in a spatial arrangement that is not superposable on its mirror image. Axial chirality is most commonly observed in atropisomeric biaryl compounds wherein the rotation about the aryl-aryl bond is restricted, for example, biphenyl, binaphthyls, e.g., 1,1'-bi-2-naphthol, and certain dihydroanthracenone compounds 
. Certain allene compounds also display axial chirality. The enantiomers of axially chiral compounds are usually given the stereochemical labels Ra and Sa, although the plus (P) or minus (M) notation (or alternatively Δ / Λ) is occasionally employed. P/M or Δ/Λ is used particularly for molecules that resemble a helix, such as hexahelicene, in which case a right-handed helix is denoted P or Δ and a left-handed helix is denoted M or Λ.

This can also be called helicity, which is the chirality of a helical, propeller or screw-shape molecular entity. P (plus) or Δ is a right-handed helix, where M (minus) or Λ is a left-handed helix.

External links

site for stereochemistry, used in organic synthesis, part of main page shown below

PAGE CREATED BY DR ANTHONY MELVIN CRASTO M.SC, Ph.D (ORGANIC CHEMISTRY,24+ years experience in the field of research and development, currently with Glenmark, Mumbai India

Ентоні  アンソニー  Αντώνιος  安东尼    แอนโทนี   Энтони   אַנטאַני  Антхони  एंथनी  안토니  أنتوني


Principal scientist, GLENMARK-GENERICS LTD

Navi mumbai, INDIA



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  安东尼    Энтони    एंथनी  안토니   Anthony in different languages

アンソニー    安东尼    Энтони    एंथनी  안토니       أنتوني

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