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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.
List of conductive polymers [1] [2]; Class Abbr. Polymer Typical dopants Peak conductivity Peak emission PA: Polyacetylene: PT: Polythiophene: Iodine, bromine, Trifluoroacetic acid, propionic acid, sulfonic acids
In organic chemistry, vinylogy is the transmission of electronic effects through a conjugated organic bonding system. [1] The concept was introduced in 1926 by Ludwig Claisen to explain the acidic properties of formylacetone and related ketoaldehydes.
[2] [3] One result of the large conjugated system is that porphyrins typically absorb strongly in the visible region of the electromagnetic spectrum, i.e. they are deeply colored. The name "porphyrin" derives from Greek πορφύρα (porphyra) 'purple'. [4]
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
Conjugated carbonyls react with secondary amines to form 3-aminocarbonyls (3-ketoamines). For example, the conjugate addition of methylamine to cyclohexen-2-one gives the compound 3-(N-methylamino)-cyclohexanone. Conjugated carbonyls react with hydrogen cyanide to 1,4-keto-nitriles. See hydrocyanation of unsaturated carbonyls.
If these groups are in direct conjugation with the pi-system of the chromophore, they may increase the wavelength at which the light is absorbed and as a result intensify the absorption. A feature of these auxochromes is the presence of at least one lone pair of electrons which can be viewed as extending the conjugated system by resonance.
The best-known example is benzene (C 6 H 6) with a conjugated system of six π electrons, which equals 4n + 2 for n = 1. The molecule undergoes substitution reactions which preserve the six π electron system rather than addition reactions which would destroy it. The stability of this π electron system is referred to as aromaticity. Still, in ...