Talk:Stereocenter
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"chiral center" vs. "chirality center"
edit"chiral center" vs. "chirality center"? Is there any difference (it seems the two are used interchangeably). Suggest changing to one or emphasizing the difference (quick google poll would indicate chiral center is more common than chirality center). — Preceding unsigned comment added by Zzzzort (talk • contribs) 22:38, 31 January 2011 (UTC)
The flash animation was horrible.
The terms "chiral center" and "chirality centre" are the same. One is the common American usage, the other the common British usage.
It reads extremely choppy having "centre in U.K." after every time the word center is used. That can't be within style guides, can it? Pharmacollie (talk) 07:17, 12 March 2022 (UTC)
Wrong definition chirality center
editI have reverted definition for chirality center which is fact is a definition for chiral carbon:
A chirality center is a stereocenter, consisting of an atom with four different entities, giving rise to two enantiomers.
Definition needs clarification for stereogenic unit!
editStereogenic redirects here. See IUPAC definition of stereogenic unit [1] — Preceding unsigned comment added by 175.38.163.188 (talk) 13:04, 17 August 2013 (UTC)
- I am not sure about the correct definition of stereocenter here. IUPAC does not seam to mention stereocenter. The IUPAC definition of stereogenic unit encompasses tetrahedral chirality (and inorganic voodoo etc), cis-trans alkene etc isomerism and, from my reading, axial chirality. In the WP article on axial chirality it states: 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.
So, what to do..? A new article?..Rename this one and subcategorize???? 175.38.163.188 (talk) 17:26, 17 August 2013 (UTC)
- And what about diastereomers based on axial chirality, they are possible and have no "stereocenter" by this existing definition! — Preceding unsigned comment added by 175.38.163.188 (talk) 18:10, 17 August 2013 (UTC)
Stereocenter, Chiral Center, and Chiral Carbon
editThe correct, logically consistent definitions can be given quite precisely. Minor differences in terms generally correspond to British vs American vs IUPAC preferred terminology.
Stereocenter (stereogenic center, stereogenic atom): An atom at which the interchange of substituents (ligands) gives rise to stereoisomers. Examples are 2-bromobutane with one stereocenter and 2-butene with two stereocenters. There are also 5-coordinate and 6-coordinate stereocenters using other atoms.
Chiral center (chirality centre): An atom holding a set of ligands in a spatial arrangement that is not superimposable on it mirror image. A subset of stereocenters. (C2 of 2-bromobutane and chiral quaternary ammonium salts are examples with 4 ligands. Other examples may contain 5 or 6 ligands.)
Chiral carbon (asymmetric carbon): A carbon atom bonded to four different substituents. A subset of chiral centers. (Most, but not all, chiral organic compounds contain one or more chiral carbons.)
Stereogencity and chirotopicity
editAs Mislow and Siegel (1984, cited) say, stereogenic and chiral have nothing to do with each other, and the two things should be separated (you cannot define one in term of the other!). The definition of stereogenic center (axis, plane) is correct as stated. Definition of chiral is Lord Kelvin's (mirror image not superimposable) and it's a property of the object as a whole. Chiral center or chirality center are oxymorons. IUPAC has not come to terms with this in the past 30 years. — Preceding unsigned comment added by 72.220.48.112 (talk) 06:08, 23 October 2014 (UTC)
Chirality was originally limited to a property of the object as a whole. Over 30 years ago, the term was expanded to apply also to a part of an object taken individually. This has contributed enormously to the ability to analyze the stereochemistry of more complex structures.
In some cases, the term "stereocenter" is le mot juste.
editFor example, in 2,3,4-trichloropentane, C3 is not a chiral center in any diastereomer. Yet C3 is a stereocenter in the meso diastereomer, but it is not a stereocenter in the chiral diastereomer. (This is easy to see using Fischer projections.)
Wiki Education assignment: Honors Organic Chemistry I
editThis article was the subject of a Wiki Education Foundation-supported course assignment, between 22 August 2022 and 2 December 2022. Further details are available on the course page. Student editor(s): ChemistryCat123, ChemistryCatSaysStop (article contribs).
— Assignment last updated by ChemistryCatSaysStop (talk) 20:16, 25 September 2022 (UTC)