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  2. Pyramidal inversion - Wikipedia

    en.wikipedia.org/wiki/Pyramidal_inversion

    Pyramidal inversion in nitrogen and amines is known as nitrogen inversion. [8] It is a rapid oscillation of the nitrogen atom and substituents, the nitrogen "moving" through the plane formed by the substituents (although the substituents also move - in the other direction); [ 9 ] the molecule passing through a planar transition state . [ 10 ]

  3. Chiral inversion - Wikipedia

    en.wikipedia.org/wiki/Chiral_inversion

    Chiral inversion is the process of conversion of one enantiomer of a chiral molecule to its mirror-image version with no other change in the molecule. [1] [2] [3] [4]Chiral inversion happens depending on various factors (viz. biological-, solvent-, light-, temperature- induced, etc.) and the energy barrier energy barrier associated with the stereogenic element present in the chiral molecule. 2 ...

  4. Inverse problem - Wikipedia

    en.wikipedia.org/wiki/Inverse_problem

    An inverse problem in science is the process of calculating from a set of observations the causal factors that produced them: for example, calculating an image in X-ray computed tomography, source reconstruction in acoustics, or calculating the density of the Earth from measurements of its gravity field. It is called an inverse problem because ...

  5. Walden inversion - Wikipedia

    en.wikipedia.org/wiki/Walden_inversion

    Walden inversion is the inversion of a stereogenic center in a chiral molecule in a chemical reaction. Since a molecule can form two enantiomers around a stereogenic center, the Walden inversion converts the configuration of the molecule from one enantiomeric form to the other.

  6. Umpolung - Wikipedia

    en.wikipedia.org/wiki/Umpolung

    In organic chemistry, umpolung (German: [ˈʔʊmˌpoːlʊŋ]) or polarity inversion is the chemical modification of a functional group with the aim of the reversal of polarity of that group. [ 1 ] [ 2 ] This modification allows secondary reactions of this functional group that would otherwise not be possible. [ 3 ]

  7. SN2 reaction - Wikipedia

    en.wikipedia.org/wiki/SN2_reaction

    If the substrate that is undergoing S N 2 reaction has a chiral centre, then inversion of configuration (stereochemistry and optical activity) may occur; this is called the Walden inversion. For example, 1-bromo-1-fluoroethane can undergo nucleophilic attack to form 1-fluoroethan-1-ol, with the nucleophile being an HO − group. In this case ...

  8. Ring flip - Wikipedia

    en.wikipedia.org/wiki/Ring_flip

    In organic chemistry, a ring flip (also known as a ring inversion or ring reversal) is the interconversion of cyclic conformers that have equivalent ring shapes (e.g., from a chair conformer to another chair conformer) that results in the exchange of nonequivalent substituent positions. [1]

  9. Chirality (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Chirality_(chemistry)

    An example of a molecule that does not have a mirror plane or an inversion and yet would be considered achiral is 1,1-difluoro-2,2-dichlorocyclohexane (or 1,1-difluoro-3,3-dichlorocyclohexane). This may exist in many conformers (conformational isomers), but none of them has a mirror plane.