Nomenclature
The
common names of alkyl halides are derived by naming the alkyl group followed by
the name of halide. In the IUPAC system of nomenclature, alkyl halides are
named as halosubstituted hydrocarbons. For mono
halogen substituted derivatives of benzene, common and IUPAC names are the
same. For dihalogen derivatives, the prefixes o-, m-,
p- are used in common system but in
IUPAC system.
The dihaloalkanes having the same type of halogen atoms are
named as alkylidene or alkylene
dihalides. The dihalo-compounds
having both the halogen atoms are further classified as geminal
halides or gem-dihalides when both the halogen atoms
are present on the same carbon atom of the chain and vicinal halides or vic-dihalides when halogen atoms are present on adjacent
carbon atoms. In common name system, gem-dihalides
are named as alkylidene halides and vic-dihalides are named as alkylene
dihalides. In IUPAC system, they are named as dihaloalkanes.