Alkyl Halides and Aryl Halides
1.0 Alkyl halides
1.0 Alkyl halides
Alkyl halides are compounds obtained from alkanes. They involve the replacement of one or more hydrogen atoms by the corresponding number of halogen atoms. They are also known as halogen derivatives of alkanes or haloalkanes.
They can be of various types:
1. Mono-halides
- These are alkyl halides which involve the replacement of only one hydrogen atom with a halogen atom.
- Their general formula is $R-X$, where $R$ is the alkyl group and $X$ is the halogen atom.
- They can be classified as primary, secondary or tertiary based on which carbon the halogen atom is attached to.
For example:
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| Primary Mono-halide | Secondary Mono-halide | Tertiary Mono-halide |
2. Di-halides
- These are obtained by the replacement of two hydrogen atoms by two halogen atoms.
- They are of three types:
Gem-halides Vic-halides Terminal-halides These are compounds in which the halogen atoms are boned to the same carbon atom. These are also known as Alkylidene halides. Compounds in which the two halogen atoms are attached to adjacent carbon atoms (i.e, the carbon atoms which are next to each other). They are also known as alkylene halides. As the name suggests, these are compounds in which the halogen atoms are bonded to the terminal carbon atoms. 
Ethylidene chloride
Propylene chloride
Trimethylene bromide
3. Tri-halides:
- Compounds which are obtained when three halogen atoms replace three hydrogen atoms are known as trihalides.
4. Poly-halide
- Compounds obtained by the replacement of $4$ hydrogen atoms by $4$ halogen atoms are tetra-halides.
- If more hydrogen atoms are replaced by halogen atoms, the corresponding compound is a poly-halide, or a poly halogen compounds.
