What is the Difference Between Vinylic and Aryl Halides

The main difference between vinylic and aryl halides is that vinylic halides are named according to the carbon atom to which the halide atom is bonded, whereas aryl halides are named according to the presence of a cyclic structure to which the halide atom is attached.

Vinyl halides and aryl halides are organic compounds. Halide atoms are directly bonded to the carbon atoms in them. These compounds are categorized depending on the carbon atom to which the halide atom is attached.

Key Areas Covered

1. What are Vinylic Halides
     – Definition, Features, Structure
2. What are Aryl Halides
     – Definition, Features, Structure
3. Difference Between Vinylic and Aryl Halides
     – Comparison of Key Differences

Key Terms

Aryl Halides, Vinylic Halides, Halides

Difference Between Vinylic and Aryl Halides - Comparison Summary

What are Vinylic Halides

Vinylic halides are compounds with the formula CH2=CHX (X = halide). A vinyl group is a functional group that has two carbon atoms double-bonded to each other and singly bonded to a hydrogen atom. The carbon atom containing the halide atom has sp2 hybridization. The geometry around the carbon atom is trigonal planar. These carbon atoms in the double bond are vinylic carbons.

Vinyl halides can exist either as a gas or a liquid at room temperature. This depends on the specific halogen atom and the size of the molecule. Moreover, the two major methods for preparing vinylic halides are dehydrohalogenation of a dihalide and the addition of a hydrogen halide to an alkyne.

Vinyl halides and bromides are present in marine natural products. Vinyl chloride is the most abundantly produced vinyl halide in the industrial setting. Its manufacture involves 1,2-dichloroethane. There are other manufacturing methods for certain vinyl halides. For example, heating chlorodifluoromethane at temperatures of 600-750* results in tetrafluoroethylene.

Compare Vinylic and Aryl Halides - What's the difference?

The polymerization of specific vinylic halides has the potential to yield commercial value. Polyvinyl chlorides are useful in floor tiles, pipes, fittings, downspouts, shingles, and houses, while allyl chloride is useful as a starting material for the synthesis of a variety of organic compounds, including allyl alcohol and allylamine and in the production of synthetic rubber and resins.

Moreover, it’s possible to convert vinylic halides to Grignard reagents. This happens by reacting with magnesium. Furthermore, vinylic halides are reactive compounds that perform many chemical reactions. One common type of reaction that vinylic halide undergo is the nucleophilic substitution reaction. This reaction is useful in the synthesis of pharmaceuticals and other organic compounds. Another important reaction of vinylic halids is the elimination reaction.

What are Aryl Halides

Aryl halides are a type of aromatic compound where a halide replaces one or more hydrogen atoms directly bonded to an aromatic ring. This aromatic ring can be either a benzene ring or any other aromatic ring system.

Several methods can manufacture aryl halides. Two of these methods are Sandmeyer reactions and halogenation of the aromatic ring. Sandmayer reactions involve the conversion of an amino group on the aromatic ring to a halogen atom using a combination of nitrous acid and a halogenating agent. Meanwhile, halogenation of the aromatic ring involves the substitution of a hydrogen atom on the ring with a halogen atom in the presence of a halogenating agent such as chlorine or bromine.

Furthermore, chrolobenze acts as a solvent and a starting material for the synthesis of a wide range of organic compounds, including dyes, plastics, and pharmaceuticals. In addition, bromobenzene is useful in the synthesis of pharmaceuticals and agrochemicals.

When compared to vinylic halides, aryl halides are relatively unreactive. This is due to the resonance stabilization provided by the aromatic ring. However, they still can undergo several reactions, such as nucleophilic aromatic substitution. Another reaction of aryl halids is the palladium-catalyzed cross-coupling reaction. This reaction helps in the synthesis of complex organic molecules.

Difference Between Vinylic and Aryl Halides

Definition

Vinylic halides are compounds with the formula CH2=CHX (X = halide), while aryl halides are a type of aromatic compound where a halide replaces one or more hydrogen atoms directly bonded to an aromatic ring.

Naming

The naming of vinylic halides depends on the carbon atom to which the halide bonds, while the naming of aryl halides depends on the attachment of the halide atom to a cyclic structure.

Reactivity

Vinyl halides are reactive, whereas aryl halides are relatively unreactive.

Structure

In vinylic halides, the halide atom is bonded to a double-bonded carbon atom, whereas in aryl halides, the halide atom is bonded to an aromatic ring.

Conclusion

In brief, vinyl halides and aryl halides are organic compounds. However, these two compounds exhibit different properties. The main difference between vinylic halides and aryl halides is that the naming of vinylic halides depends on the carbon atom to which the halide bonds, while the naming of aryl halides depends on the attachment of the halide atom to a cyclic structure.

Reference:

1. Barns. Kerry. “Aryl Halide: Structure & Reactions.” Study.com
2. “Vinylic halides.” Encyclopedia Britannica. 

Image Courtesy:

1. “Vinilxlorid” By Kəmalə baxa – Own work (CC BY-SA 4.0) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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