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What does a locant show in the IUPAC name of an organohalogen compound?
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organohalogen compound
Vinyl chloride is an organohalogen compound that has important industrial applications. When treated with certain catalysts, vinyl chloride monomers undergo polymerization and form the larger compound known as polyvinyl chloride, or PVC. PVC is used in the manufacture of numerous products, including packaging films and water pipes.
In the IUPAC substitutive nomenclature of an organohalogen compound, a locant is a number used to identify the specific carbon atom within the hydrocarbon framework to which a halogen atom is attached.1
By designating the position of the substituent, the locant ensures the chemical name accurately reflects the molecule's structure. When naming these compounds, the halogen is cited as a prefix (such as fluoro-, chloro-, bromo-, or iodo-) alongside this numerical locant.231