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Cinnamaldehyde Clock
Dicinnamalacetone is a Conjugated system, conjugated organic compound. It is used as an indicator for the presence of hydrogen halides in solvents, and its preparation is used as an example of the aldol condensation in organic chemistry teaching labs. Preparation Dicinnamalacetone (specifically the all-''trans'' isomer) may be prepared by the reaction of acetone and ''Cis–trans isomerism, trans-''cinnamaldehyde catalyzed by a strong base, such as potassium hydroxide. The reaction is typically conducted in a mixture of water and ethanol. Clock reaction The preparation of dicinnamalacetone is an example of a Chemical clock, clock reaction. Upon the addition of acetone to a solution of ''trans''-cinnamaldehyde and potassium hydroxide in ethanol and water, a Precipitation (chemistry), precipitate of dicinnamalacetone forms spontaneously after a delay. The formation of dicinnamalacetone constitutes two separate Aldol condensation, aldol condensations. In the first, one molar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjugated System
In physical organic 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 Chemical stability, stability. It is Resonance (chemistry), conventionally represented as having alternating single and multiple covalent bond, bonds. Lone pairs, radical (chemistry), radicals or carbenium ions may be part of the system, which may be Cyclic molecule, cyclic, acyclic, Linear molecular geometry, linear or mixed. The term "conjugated" was coined in 1899 by the German chemist Johannes Thiele (chemist), Johannes Thiele. Conjugation is the orbital overlap, overlap of one p-orbital with another across an adjacent Sigma bond, σ bond (in transition metals, d-orbitals can be involved). A conjugated system has a region of overlapping p-orbitals, bridging the interjacent locations that simple diagrams illustrate as not having a π bond. They allow a delocalization of pi el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
