Which of the following compounds are capable of cis–trans isomerism?
a.
b.
c.

Verified step by step guidance

1. Step 1: Understand the concept of cis–trans isomerism. Cis–trans isomerism occurs in compounds with restricted rotation, typically due to a double bond or a ring structure. For a compound to exhibit cis–trans isomerism, it must have two different groups attached to each carbon of the double bond or to the ring system.
2. Step 2: Analyze compound (a). Check if the compound has a double bond or a ring structure. Then, verify if each carbon in the double bond or ring has two different groups attached. If both conditions are met, the compound can exhibit cis–trans isomerism.
3. Step 3: Analyze compound (b). Repeat the same process as in Step 2. Look for a double bond or ring structure and confirm if the groups attached to the relevant carbons are different.
4. Step 4: Analyze compound (c). Again, check for the presence of a double bond or ring structure and ensure that each carbon involved has two different groups attached.
5. Step 5: Summarize your findings. Based on the analysis of each compound, determine which ones meet the criteria for cis–trans isomerism and explain why they do or do not exhibit this type of isomerism.

Key Concepts

Cis-Trans Isomerism

Cis-trans isomerism, also known as geometric isomerism, occurs in compounds with restricted rotation around a bond, typically a double bond. In this type of isomerism, the spatial arrangement of groups attached to the carbon atoms can differ, leading to distinct isomers. 'Cis' refers to isomers where similar groups are on the same side, while 'trans' indicates they are on opposite sides. This phenomenon is crucial in understanding the physical and chemical properties of compounds.

Criteria for Cis-Trans Isomerism

For a compound to exhibit cis-trans isomerism, it must have at least one double bond or a ring structure that restricts rotation. Additionally, the compound must have two different substituents attached to each carbon involved in the double bond or ring. This requirement ensures that distinct spatial arrangements can exist, allowing for the identification of cis and trans forms. Understanding these criteria is essential for determining which compounds can exhibit this type of isomerism.

Examples of Compounds with Cis-Trans Isomerism

Common examples of compounds that can exhibit cis-trans isomerism include alkenes, such as 2-butene, and certain cyclic compounds, like cyclohexane derivatives. In 2-butene, the presence of a double bond between the two central carbon atoms allows for the formation of cis and trans isomers based on the positioning of the methyl groups. Recognizing these examples helps in visualizing how cis-trans isomerism manifests in various chemical structures.