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  2. 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.

  3. SNi - Wikipedia

    en.wikipedia.org/wiki/SNi

    In chemistry, S N i (substitution nucleophilic internal) refers to a specific, regio-selective but not often encountered reaction mechanism for nucleophilic aliphatic substitution. The name was introduced by Cowdrey et al. in 1937 to label nucleophilic reactions which occur with retention of configuration, [ 1 ] but later was employed to ...

  4. 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 ]

  5. Kovats retention index - Wikipedia

    en.wikipedia.org/wiki/Kovats_retention_index

    While retention times vary with the individual chromatographic system (e.g. with regards to column length, film thickness, diameter and inlet pressure), the derived retention indices are quite independent of these parameters and allow comparing values measured by different analytical laboratories under varying conditions and analysis times from ...

  6. 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 ...

  7. Concerted reaction - Wikipedia

    en.wikipedia.org/wiki/Concerted_reaction

    S N 2 reaction of a bromide ion with chloroethane showing the concerted nature of the reaction, the transition state and the predictable stereochemistry through Walden inversion. In chemistry , a concerted reaction is a chemical reaction in which all bond breaking and bond making occurs in a single step .

  8. Conversion (chemistry) - Wikipedia

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

    Conversion and its related terms yield and selectivity are important terms in chemical reaction engineering.They are described as ratios of how much of a reactant has reacted (X — conversion, normally between zero and one), how much of a desired product was formed (Y — yield, normally also between zero and one) and how much desired product was formed in ratio to the undesired product(s) (S ...

  9. Intimate ion pair - Wikipedia

    en.wikipedia.org/wiki/Intimate_ion_pair

    In chemistry, the intimate ion pair concept, introduced by Saul Winstein, describes the interactions between a cation, anion and surrounding solvent molecules. [1] In ordinary aqueous solutions of inorganic salts, an ion is completely solvated and shielded from the counterion. In less polar solvents, two ions can still be connected to some extent.