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  2. Carbocation - Wikipedia

    en.wikipedia.org/wiki/Carbocation

    The IUPAC acknowledges the three divergent definitions of carbonium ion and urges care in the usage of this term. For the remainder of this article, the term carbonium ion will be used in this latter restricted sense, while non-classical carbocation will be used to refer to any carbocation with C–C and/or C–H σ-bonds delocalized by bridging.

  3. Vinyl cation - Wikipedia

    en.wikipedia.org/wiki/Vinyl_cation

    It may either destabilize the cation by drawing even more electron density from the carbon or stabilizing by contributing more electron density. The carbocation positive charge can be relieved by an unsaturated carbon-based or heteroatomic substituent through p-donation and/or C-H hyperconjugation by methylene/methyl substituents. In addition ...

  4. Conjugated system - Wikipedia

    en.wikipedia.org/wiki/Conjugated_system

    Cinnamaldehyde is a naturally-occurring compound that has a conjugated system penta-1,3-diene is a molecule with a conjugated system Diazomethane conjugated pi-system. In theoretical chemistry, a conjugated system is a system of connected p-orbitals with delocalized electrons in a molecule, which in general lowers the overall energy of the molecule and increases stability.

  5. Markovnikov's rule - Wikipedia

    en.wikipedia.org/wiki/Markovnikov's_rule

    Adding the hydrogen ion to one carbon atom in the alkene creates a positive charge on the other carbon, forming a carbocation intermediate. The more substituted the carbocation, the more stable it is, due to induction and hyperconjugation. The major product of the addition reaction will be the one formed from the more stable intermediate.

  6. SN2 reaction - Wikipedia

    en.wikipedia.org/wiki/SN2_reaction

    The rate of an S N 2 reaction is second order, as the rate-determining step depends on the nucleophile concentration, [Nu −] as well as the concentration of substrate, [RX]. [1] r = k[RX][Nu −] This is a key difference between the S N 1 and S N 2 mechanisms.

  7. Carbene - Wikipedia

    en.wikipedia.org/wiki/Carbene

    Methylene is the simplest carbene.. In organic chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons.The general formula is R−:C−R' or R=C: where the R represents substituents or hydrogen atoms.

  8. Cationic polymerization - Wikipedia

    en.wikipedia.org/wiki/Cationic_polymerization

    In cationic polymerization, the ions tend to be in equilibrium between an ion pair (either tight or solvent-separated) and free ions. [2] The more polar the solvent used in the reaction, the better the solvation and separation of the ions. Since free ions are more reactive than ion pairs, the rate of propagation is faster in more polar solvents.

  9. Reaction intermediate - Wikipedia

    en.wikipedia.org/wiki/Reaction_intermediate

    In S N 1, a leaving group is broken off to create a carbocation reaction intermediate. Then, a nucleophile attacks and forms a new bond with the carbocation intermediate to form the final, substituted product, as shown in the reaction of 2-bromo-2-methylpropane to form 2-methyl-2-propanol. [4] (CH 3) 3 CBr → (CH 3) 3 C + (CH 3) 3 C + + H 2 O ...