IEO Level 2- English Olympiad (SOF) Class 9 Coaching Programs

⏳ 🎯 Online Tests (2 Tests [50 Questions Each]): NTA Pattern, Analytics & Explanations

Click Here to View & Get Complete Material

Rs. 200.00

3 Year Validity (Multiple Devices)

πŸŽ“ Study Material (303 Notes): 2024-2025 Syllabus

Click Here to View & Get Complete Material

Rs. 450.00

3 Year Validity (Multiple Devices)

🎯 250 MCQs (& PYQs) with Full Explanations (2024-2025 Exam)

Click Here to View & Get Complete Material

Rs. 200.00

3 Year Validity (Multiple Devices)

Compound of Carbon Containing Halogen: Nomenclature of Haloalkanes

Nomenclature of Haloalkanes

Rules for naming haloalkanes according to the IUPAC system are as follows:

The longest chain of the carbon atoms bearing the halogen atom is selected.

Illustration: Nomenclature of Haloalkanes

The longest chain of carbon atoms in the above example is shown in the box.

Numbering of the carbon atoms in the chain is done in such a way that the carbon atom bearing the halogen atom gets the lowest number. For example,

Illustration: Nomenclature of Haloalkanes

The word chloro, is prefixed to the parent hydrocarbon name. So, the correct name for the above halo compound is

Illustration: Nomenclature of Haloalkanes

In alkyl substituted haloalkanes, the longest chain containing halogen atom is selected for numbering. For example,

Illustration: Nomenclature of Haloalkanes
  • In structure I , both the ways of selection are correct since they include chloro group.
  • In structure II numbering shown is not correct since it does not include chloro group.

When two or more halogen atoms are present in a compound, the longest chain selected must contain the maximum number of halogen atoms . The multiplicative prefixes (di, tri, tetra, etc.) are added before the name of halogen atom to indicate the number of halogen atoms. For example,

Illustration: Nomenclature of Haloalkanes
Illustration: Nomenclature of Haloalkanes

Nomenclature of Haloarenes

  • Haloarenes are those aromatic halogen compounds in which the halogen atom is directly linked to an aromatic ring.
  • General formula is Ar-X where Ar- represents an aromatic ring and X denotes the halogen.
  • In naming a haloarene, the prefix chloro, bromo-or iodo- etc. is are added to name of arene according to halogen (s) present.
  • The relative positions of halogen atoms are indicated by appropriate numbers.
  • The prefixes ortho (o-) , meta (m-) and para (p-) are also commonly used respectively to indicate the relative positions i.e.. 1,2-, 1,3- and 1,4- of substituents in a benzene ring.

Examples of nomenclature of haloarenes are as follows:

Illustration: Nomenclature of Haloarenes