enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Nucleophile - Wikipedia

    en.wikipedia.org/wiki/Nucleophile

    A hydroxide ion acting as a nucleophile in an S N 2 reaction, converting a haloalkane into an alcohol. In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they ...

  3. Flippin–Lodge angle - Wikipedia

    en.wikipedia.org/wiki/Flippin–Lodge_angle

    The Flippin–Lodge angle is one of two angles used by organic and biological chemists studying the relationship between a molecule's chemical structure and ways that it reacts, for reactions involving "attack" of an electron-rich reacting species, the nucleophile, on an electron-poor reacting species, the electrophile.

  4. Electrophile - Wikipedia

    en.wikipedia.org/wiki/Electrophile

    In chemistry, an electrophile is a chemical species that forms bonds with nucleophiles by accepting an electron pair. [1] Because electrophiles accept electrons, they are Lewis acids. [2] Most electrophiles are positively charged, have an atom that carries a partial positive charge, or have an atom that does not have an octet of electrons.

  5. Molecules in stars - Wikipedia

    en.wikipedia.org/wiki/Molecules_in_stars

    Some molecules are sensitive to the ratio of elements, and so indicate elemental composition of the star. [6] Different molecules are characteristic of different kinds of stars, and are used to classify them. [5] Because there can be numerous spectral lines of different strength, conditions at different depths in the star can be determined.

  6. HSAB theory - Wikipedia

    en.wikipedia.org/wiki/HSAB_theory

    An application of HSAB theory is the so-called Kornblum's rule (after Nathan Kornblum) which states that in reactions with ambident nucleophiles (nucleophiles that can attack from two or more places), the more electronegative atom reacts when the reaction mechanism is S N 1 and the less electronegative one in a S N 2 reaction.

  7. Bürgi–Dunitz angle - Wikipedia

    en.wikipedia.org/wiki/Bürgi–Dunitz_angle

    In the addition of a nucleophile (Nu) attack to a carbonyl, the BD angle is defined as the Nu-C-O bond angle. The BD angle adopted during an approach by a nucleophile to a trigonal unsaturated electrophile depends primarily on the molecular orbital (MO) shapes and occupancies of the unsaturated carbon center (e.g., carbonyl center), and only secondarily on the molecular orbitals of the ...

  8. SN2 reaction - Wikipedia

    en.wikipedia.org/wiki/SN2_reaction

    For example, OH − is a better nucleophile than water, and I − is a better nucleophile than Br − (in polar protic solvents). In a polar aprotic solvent, nucleophilicity increases up a column of the periodic table as there is no hydrogen bonding between the solvent and nucleophile; in this case nucleophilicity mirrors basicity.

  9. Epoxide - Wikipedia

    en.wikipedia.org/wiki/Epoxide

    The peroxide is viewed as an electrophile, and the alkene a nucleophile. The reaction is considered to be concerted. The reaction is considered to be concerted. The butterfly mechanism allows ideal positioning of the O−O sigma star orbital for C−C π electrons to attack. [ 14 ]