What are the most common reactions involving aromatics?
What are the most common reactions involving aromatics?
Substitution Reactions of Benzene and Other Aromatic Compounds
| Reaction Type | Typical Equation | |
|---|---|---|
| Nitration: | C6H6 | + HNO3 & heat H2SO4 catalyst |
| Sulfonation: | C6H6 | + H2SO4 + SO3 & heat |
| Alkylation: Friedel-Crafts | C6H6 | + R-Cl & heat AlCl3 catalyst |
| Acylation: Friedel-Crafts | C6H6 | + RCOCl & heat AlCl3 catalyst |
What type of reaction do aromatics undergo?
Aromatic compounds react by electrophilic aromatic substitution reactions, in which the aromaticity of the ring system is preserved. For example, benzene reacts with bromine to form bromobenzene. Many functional groups can be added to aromatic compounds via electrophilic aromatic substitution reactions.
How do you know if something is aromatic?
A molecule is aromatic when it adheres to 4 main criteria:
- The molecule must be planar.
- The molecule must be cyclic.
- Every atom in the aromatic ring must have a p orbital.
- The ring must contain pi electrons.
Why are aromatic compounds unreactive?
Because of the low hydrogen to carbon ratio in aromatic compounds (note that the H:C ratio in an alkane is >2), chemists expected their structural formulas would contain a large number of double or triple bonds.
What is the importance of aromatic hydrocarbons?
One of the main uses for aromatic hydrocarbons is as a non-polar solvent for other molecules. Thus, aromatic hydrocarbons can be used as additives in gasoline, paints, lacquers, and other solutions. Their low reactivity also contributes to their use as a solvent.
Are aromatic rings good nucleophiles?
A nucleophilic aromatic substitution is a substitution reaction in organic chemistry in which the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring. Aromatic rings are usually nucleophilic, but some aromatic compounds do undergo nucleophilic substitution.
Which is the least reactive towards aromatic electrophilic substitution?
Benzenesulphonic acid is least reactive in an electrophilic aromatic substitution due to −M effect.
Are aromatic rings planar?
The three general requirements for a compound to be aromatic are: The compound must be cyclic. Each element within the ring must have a p-orbital that is perpendicular to the ring, hence the molecule is planar. This means that the ring cannot contain a neutral sp3 carbon.
What are the necessary conditions for any system to be aromatic?
The necessary conditions for any system to be aromatic are planar, conjugated ring system with delocalisation of (4n+2)π electrons, where, n is an integer.
Are aromatics flammable?
Description. Aromatic hydrocarbons are all combustible. The lightest members of this class, benzene and substituted benzenes, have high enough vapor pressures and low enough flash points to be vapor explosion hazards.
Why does aromaticity increase stability?
In terms of the electronic nature of the molecule, aromaticity describes a conjugated system often made of alternating single and double bonds in a ring. This configuration allows for the electrons in the molecule’s pi system to be delocalized around the ring, increasing the molecule’s stability.
