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Chemistry Stack Exchange

Questions tagged [chirality]

Applicable to questions about the ability of a molecule (or class of molecules) to be superimposed on their mirror image(s).

Tag usage

This tag should be used on questions about:

  • Whether a molecule or class of molecules is chiral
  • Group theoretical treatments of chirality
  • Chirality in biomolecules e.g. DNA, proteins
  • The effect of chirality on properties or the reactions of chiral compounds

Definition

Chirality is defined in the IUPAC Gold Book as:

The geometric property of a rigid object (or spatial arrangement of points or atoms) of being non-superposable on its mirror image; such an object has no symmetry elements of the second kind (a mirror plane, σ = S1, a centre of inversion, i = S2, a rotation-reflection axis, S2n). If the object is superposable on its mirror image the object is described as being achiral.

Further reading

The question: What is the perfect definition for chirality? and the answers therein provide an excellent overview of chirality.

258 questions
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Are there reactions where the stirring direction would make a difference?

I'm not a chemist. I don't really do anything with chemistry, so I know little of the subject. I know a bit about chiral molecules. For example, I know that homochirality can affect light polarity. I'm just curious: Are there chemical reactions…
ChocolateOverflow
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How is the cavity of a cyclodextrin chiral?

I am studying the host-guest chemistry of cyclodextrins with achiral aromatic molecules, and I found out that a useful way of studying them is by induced circular dichroism spectroscopy. This technique is used by taking an achiral molecule and…
Gabi
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3
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Why is 2-chloropropene achiral?

Could someone explain to me why some alkenes containing at least one couple of different substituents at the two double-bonded C atoms (that is, some of those with at least two different substituents for both C atoms) are considered achiral? For…
Adrian
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Is chirality a physical or a chemical property?

In my opinion, it should be both, because it will affect the way in which a molecule will interact with plane polarized light (physical), but also affect chemical interactions such as receptor binding. On the other hand, consider $\ce{CHDBrCH3}$,…
Matthieu Kratz
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3
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Is bicyclo[1.1.0]butane chiral?

Is bicyclo[1.1.0]butane chiral? I think it isn't, but if one of the hydrogen atoms bound to the tertiary or secondary carbon atoms is replaced with e.g. chlorine, the formed compound will be chiral, right?
EJC
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2
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How would you change the chirality of a compound such that (S,R) becomes (S,S)?

How would you change the chirality of a compound such that (S,R) becomes (S,S)? That is how would you synthesise a compound from its diastereomer?
Josh Pinto
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Is Inositol chiral or achiral?

I thought Inositol was clearly chiral since it has 6 asymmetric C atoms. But friends of me argue that it is achiral and i've found websites say the same (http://bip.cnrs-mrs.fr/bip10/Inositol-EJB.pdf). So what am I missing? Is it chiral or achiral?
Lukeception
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Enantiomers and Flipping chiral centres

Hello, Normally, it seems like enantiomers have inverted R/S configuration at every chiral centre. However, in the pair below which are clearly enantiomers (note the methyl and benzyl groups are going in and out of page) as mirror image of one is…
Chemz
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Is chirality a property of only molecules with exactly 1 chiral centre?

I have seen chirality being defined in a number of ways in terms of a molecule not being superimposable with its mirror image. My syllabus has a statement: "know that optical isomerism is a result of of chirality in molecules with a single chiral…
VACT-1729
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Can sp2 hybridised carbon show chirality?

I know that any carbon to show chirality has to be bonded to 4 different atoms (groups of atoms). So a double bond is considered as that the carbon is achiral. I learnt from my lecturer that dissubstituted allene is an exception. If it is true that…
Adhesh Sagar
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Why is 1-Ethyl-1-methylcyclohexane achiral?

I was wondering why the 1-Ethyl-1-methylcyclohexane molecule is achiral. Thank you in advance.
Matt
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R/S chirality question

Consider [(1⁠S,2⁠S,4⁠S)-bicyclo[2.2.1]hept-5-en-2-yl]acetic acid: (Source: http://www.chemspider.com/Chemical-Structure.22823922.html) According to the chemspider nomenclature, this has three S stereocenters. However, when I perform the CIP both…
confused chemist
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Configuration, chirality

I'm having trouble assigning priorities for this molecule: I tried assigning priorities with the rules for doubly bonded atoms in mind. I know that the lowest priority group should be going into the page (not on a wedge) but I read that I can simply…
Dissenter
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Is 2 ethyl 3 methyl oxirane optically active?

According to me this molecule does not have any any plane of symmetry nor centre of symmetry, but in my textbook it is given that this is optically inactive.
user102573
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1 answer

Why has this molecule a S-chirality?

Can someone explain to me, why this molecule has an (S)-chirality? I don't get it. I tried to apply the rules, but I get only an (R)-chirality. Is there something special with cyclo-alkanes?
Seminom
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