Video Transcript
According to the IUPAC nomenclature, what name does the following benzene derivative have?
Benzene is a cyclic hydrocarbon that contains six carbon atoms and six hydrogen atoms. It can be represented using a displayed formula, skeletal formula showing alternating single and double bonds, or a skeletal formula with a circle in the middle which represents the delocalized ring of electron density in a benzene molecule.
The molecule provided in the question is a benzene derivative. In this derivative, we can see the ring structure of benzene, but one of the hydrogen atoms has been replaced by a chlorine atom. As only one substituent is attached to the ring, this molecule is classified as a monosubstituted benzene derivative, or a monosubstituted arene.
This type of molecule is easily named following IUPAC nomenclature. IUPAC stands for the International Union of Pure and Applied Chemistry. This organization is the prevailing authority on chemical nomenclature and terminology. According to IUPAC nomenclature, if the single substituent is not an alkyl chain with other functional groups or an alkyl chain with seven or more carbon atoms, the benzene ring is classified as the parent chain. So when naming this compound, we can start by naming the parent chain benzene.
We then need to place the name of the substituent in front of the parent chain name. When chlorine is a substituent, it’s given the name chloro. So we place the term chloro directly in front of the word benzene without any spaces or dashes. With monosubstituted benzene derivatives, position numbers on the benzene ring are not included as a part of the name. Therefore, according to the IUPAC nomenclature, the name of this benzene derivative is chlorobenzene.
