Question

Give the IUPAC names of the following compounds: (i) \(\mathrm{CH}_{3} \mathrm{CH}(\mathrm{Cl}) \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_{3}\) (ii) \(\mathrm{CHF}_{2} \mathrm{CBrClF}\) (iii) \(\mathrm{ClCH}_{2} \mathrm{C} \equiv \mathrm{CCH}_{2} \mathrm{Br}\) (iv) \(\left(\mathrm{CCl}_{3}\right)_{3} \mathrm{CCl}\) (v) \(\mathrm{CH}_{3} \mathrm{C}\left(p-\mathrm{ClC}_{6} \mathrm{H}_{4}\right)_{2} \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_{3}\) (vi) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCH}=\mathrm{CClC}_{6} \mathrm{H}_{4} \mathrm{I}-p\)

Short answer

(i) 2-chloro-3-bromobutane; (ii) 1,1-difluoro-2-bromo-2-chloro-2-fluoroethane; (iii) 4-bromo-1-chlorobut-1-yne; (iv) Tris(trichloromethyl)methane; (v) 1-bromo-2,2-bis(4-chlorophenyl)propane; (vi) 1-tert-butyl-2-(4-iodophenyl)prop-1-ene.

Step-by-step solution

Name the parent chain

For compound (i) \(\mathrm{CH}_{3} \mathrm{CH}(\mathrm{Cl}) \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_{3}\), the parent chain is the longest continuous chain of carbon atoms. Here, it is butane, a four-carbon alkane.

Identify and name the substituents

For compound (i), the substituents are \(-Cl\) (chloro) on carbon 2 and \(-Br\) (bromo) on carbon 3 of the butane chain.

Determine the numbering of the chain

Number the carbon atoms in the chain so the substituents have the lowest possible numbers. In this case, number from left to right, giving chloro the number 2 and bromo the number 3.

Write the compound name

Combine the substituents and parent name, following IUPAC conventions. The compound (i) is named 2-chloro-3-bromobutane.

Apply steps 1-4 for compound (ii)

For \(\mathrm{CHF}_{2} \mathrm{CBrClF}\), the parent chain is ethane (two carbons). The substituents are difluoro on carbon 1, and bromo, chloro, and fluoro on carbon 2. Name: 1,1-difluoro-2-bromo-2-chloro-2-fluoroethane.

Apply steps 1-4 for compound (iii)

For \(\mathrm{ClCH}_{2} \mathrm{C} \equiv \mathrm{CCH}_{2} \mathrm{Br}\), the parent chain is butyne (a four-carbon chain with a triple bond). Substituents are chloro and bromo at positions 1 and 4, respectively. Name: 4-bromo-1-chlorobut-1-yne.

Apply steps 1-4 for compound (iv)

For \(\left(\mathrm{CCl}_{3}\right)_{3} \mathrm{CCl}\), the parent structure is a methane-based core. There are three trichloromethyl groups and one chlorine atom directly attached to the central carbon. Name: tetrachloro-\(\mathrm{CCl}_{3}\) is considered trivial, so its IUPAC is tetrachloromethane and the entire compound still falls under trichloromethyl (as usually acknowledged).

Apply steps 1-4 for compound (v)

For \(\mathrm{CH}_{3} \mathrm{C}(p-\mathrm{ClC}_{6}\mathrm{H}_{4})_{2} \mathrm{CH}(\mathrm{Br}) \mathrm{CH}_{3}\), the parent chain is the longest carbon chain, which includes the biphenyl group. The substituents are bromo and para-chlorophenyl on the main chain. Name: 1-bromo-2,2-bis(4-chlorophenyl)propane.

Apply steps 1-4 for compound (vi)

For \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCH}=\mathrm{CClC}_{6}\mathrm{H}_{4} \mathrm{I}-p\), the parent chain involves a butene structure with iodine substituent at the para position of the phenyl ring. Name: 1-tert-butyl-2-(4-iodophenyl)prop-1-ene.

Key concepts

Organic Compounds

Organic compounds are essentially chemical compounds that primarily contain carbon atoms in combination with hydrogen, and often along with oxygen, nitrogen, sulfur, phosphorus, or halogens. These compounds are the building blocks of all living matter and are crucial in various industrial applications.
Some of the simplest organic compounds are hydrocarbons, which are made entirely of carbon and hydrogen atoms. These include alkanes like methane, ethane, and propane, and alkenes like ethene and propene.
When dealing with more complex organic compounds, it is common to encounter molecules that include functional groups such as \(-\mathrm{OH}\) (hydroxy group) or \(-\mathrm{NH}_2\) (amino group). These functional groups give rise to specific chemical properties and reactivity patterns.
Overall, organic compounds form the foundation of organic chemistry, which studies their structure, properties, composition, reactions, and synthesis.

Substituents

In organic chemistry, substituents are atoms or groups of atoms that are attached to the main carbon chain or ring structure within a molecule. These substituents can significantly affect the physical and chemical properties of the compounds they are part of. Understanding the role of substituents is essential for IUPAC nomenclature and other naming conventions.
Substituents are named based on the type of atom or group they represent, often ending in the suffix \'-yl\', such as methyl \(-\mathrm{CH}_3\)\ or ethyl \(-\mathrm{C}_2\mathrm{H}_5\)\ group.
In the context of IUPAC naming, substituents are usually listed alphabetically if multiple ones are present, and each is given a number indicating its position on the parent chain. This helps in constructing a concise and precise name of the compound.

• Common substituents include: alkyne, halo, nitro, alkoxy, and amino groups.


• The position of a substituent is crucial in influencing the reactivity and physical attributes of the molecule.

Understanding substituents is key to determining a compound's overall behavior and its possible applications.

Naming Conventions

IUPAC nomenclature is the internationally accepted method for naming organic compounds. It provides a systematic way of naming compounds so that each name clearly identifies a distinct chemical structure. This system involves several straightforward steps.
The first step in this procedure is to identify the longest carbon chain in a molecule, which is known as the parent chain. Once identified, the parent chain determines the base name of the compound, such as "butane" for a four-carbon alkane.
Next, substituents attached to the carbon chain are identified and named. Their positions on the chain are assigned the lowest possible numbers to ensure that names are both accurate and concise.
The final IUPAC name is formed by combining the names and positions of the substituents with the name of the parent chain.

• Remember to use prefixes like di-, tri-, etc., when multiple identical substituents are present.


• Compounds with multiple functional groups are named by identifying the highest priority group as a suffix while others are prefixed.

This systematic naming is vital for clear communication in the field of chemistry.

Alkanes and Alkenes

Alkanes and alkenes are types of hydrocarbons, compounds composed solely of hydrogen and carbon. These two groups are staples of organic chemistry and differ significantly in their structure and properties.
Alkanes are saturated hydrocarbons, meaning they contain only single bonds between carbon atoms. This makes them relatively stable and less reactive. They are often used as fuels and lubricants due to their chemical characteristics. Examples include methane (\(\mathrm{CH}_4\)) and butane (\(\mathrm{C}_4\mathrm{H}_{10}\)).
In contrast, alkenes are unsaturated hydrocarbons characterized by at least one double bond between carbon atoms. This double bond introduces reactivity, making alkenes useful as starting materials in the synthesis of various industrial chemicals. Common alkenes include ethene (\(\mathrm{CH}_2\mathrm{=CH}_2\)) and propene (\(\mathrm{CH}_3\mathrm{CH=CH}_2\)).

• Alkanes follow the general formula \(\mathrm{C}_n\mathrm{H}_{2n+2}\).
• Alkenes adhere to \(\mathrm{C}_n\mathrm{H}_{2n}\).
• The presence of double bonds in alkenes permits geometric isomerism, like cis-trans isomerism.

Understanding these basic differences is essential for mastering organic chemistry. Knowing when a compound is an alkane or an alkene instantly tells a lot about its chemical properties and uses.