Term used to refer to stereoisomerism resulting from the non-planar arrangement of four groups in pairs about a chirality axis. Axial chirality is a case of chirality in which a molecule does not posess a asymmetric carbon atom (the 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 which is not superposable on its mirror image. Axial chirality is most commonly observed in atropisomeric biaryl compounds (where the rotation about the aryl-aryl bond is restricted), for example biphenyl, [1] (http://siggy.chem.ucla.edu/VOH/30A/Dinitrobiphenyl_(COOH)2.pdf#search='axial%20chirality'), binaphthyls (e.g., 1,1'-bi-2-naphthol), and certain dihydroanthracenone compounds [2] (http://www.arkat-usa.org/ark/journal/2004/I10_Rickards/RI-1154C/RI-1154C.asp). 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 is occasionally employed. In chemistry, a molecule is chiral if is not superimposable on its mirror image regardless of how it is contorted. ... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... 1,1-bi-2-naphthol or 1,1-binaphthol or 1,1-binaphthalene]-2,2-diol or BINOL is an organic compound which is often used as a ligand for transition-metal catalysed asymmetric synthesis. ... An Allene is an hydrocarbon in which one atom of carbon is connected by double bonds with two other atoms of carbon. ...
Chirality is of interest because of its application to stereochemistry in inorganic chemistry, organic chemistry, physical chemistry and biochemistry.
Technically, a molecule is achiral (not chiral) if and only if it has an axis of improper rotation; that is, an n-fold rotation (rotation by 360°/n) followed by a reflection in the plane perpendicular to this axis which maps the molecule onto itself.
Chiral compounds exhibit optical activity, so enantiomers are also called optical isomers.
Chiralmolecules are sometimes referred to as being "dissymmetric"; chirality and dissymmetry being one in the same.
A molecule is achiral rs chirality in chemistry (that is, not chiral) if and only if it has an axis of improper rotation, that is, an n-fold rotation (rotation by 360°/n) followed by a reflection in the plane perpendicular to chirality anime this axis which maps the molecule on to itself.
Chirality is of critical importance in chemistry and unites the traditionally-defined subdisciplines of inorganic chemistry, organic chemistry and physical chemistry.
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