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  2. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...

  3. Clar's rule - Wikipedia

    en.wikipedia.org/wiki/Clar's_rule

    Clar's rule is widely applied in the fields of chemistry and materials science. For instance, Clar's rule can be used to predict several properties of graphene nanoribbons . [ 10 ] Aromatic π-sextets play an important part in the determination of the ground state of open shell biradical -type structures., [ 4 ] Clar's rule can rationalize the ...

  4. Character table - Wikipedia

    en.wikipedia.org/wiki/Character_table

    Complex conjugation acts on the character table: since the complex conjugate of a representation is again a representation, the same is true for characters, and thus a character that takes on non-real complex values has a conjugate character. Certain properties of the group G can be deduced from its character table:

  5. 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.

  6. Antiaromaticity - Wikipedia

    en.wikipedia.org/wiki/Antiaromaticity

    The molecule must have a complete conjugated π-electron system within the ring. The molecule must have 4n π-electrons where n is any integer within the conjugated π-system. This differs from aromaticity only in the fourth criterion: aromatic molecules have 4n +2 π-electrons in the conjugated π system and therefore follow Hückel’s rule ...

  7. Homoconjugation - Wikipedia

    en.wikipedia.org/wiki/Homoconjugation

    In chemistry, homoconjugation has two unrelated meanings: In acid–base chemistry, homoconjugation is an alternate name for the phenomenon of homoassociation. In organic chemistry, homoconjugation is a type of conjugated system where two π-systems are separated by one non-conjugating group. See Conjugated system#Mechanism

  8. SN1CB mechanism - Wikipedia

    en.wikipedia.org/wiki/Sn1CB_mechanism

    In coordination chemistry, the S N 1cB (conjugate base) mechanism describes the pathway by which many metal amine complexes undergo substitution, that is, ligand exchange. Typically, the reaction entails reaction of a polyamino metal halide with aqueous base to give the corresponding polyamine metal hydroxide: [ 1 ]

  9. Conjugate (acid-base theory) - Wikipedia

    en.wikipedia.org/wiki/Conjugate_(acid-base_theory)

    On the other hand, if a chemical is a weak acid its conjugate base will not necessarily be strong. Consider that ethanoate, the conjugate base of ethanoic acid, has a base splitting constant (Kb) of about 5.6 × 10 −10, making it a weak base. In order for a species to have a strong conjugate base it has to be a very weak acid, like water.