For each of the following compounds, indicate whether or not it can exist as cis–trans stereoisomers. If it can exist as the two isomers, draw both as a condensed structure.
(c)

Verified step by step guidance

1. Identify the structural requirements for a compound to exhibit cis-trans stereoisomerism. Cis-trans isomerism occurs in compounds with restricted rotation, such as double bonds, and requires two different groups attached to each carbon of the double bond.
2. Examine the structure of the compound provided in the problem (not shown here). Look for a double bond in the molecule and check if each carbon atom involved in the double bond has two different groups attached to it.
3. If the compound meets the criteria for cis-trans isomerism, label the two possible configurations: 'cis' (where the identical or similar groups are on the same side of the double bond) and 'trans' (where the identical or similar groups are on opposite sides of the double bond).
4. Draw the condensed structural formulas for both the cis and trans isomers. Ensure that the placement of groups around the double bond reflects the correct spatial arrangement for each isomer.
5. If the compound does not meet the criteria for cis-trans isomerism (e.g., if one of the carbons in the double bond has two identical groups), explain why it cannot exhibit this type of stereoisomerism.

Key Concepts

Cis-Trans Stereoisomerism

Cis-trans stereoisomerism refers to a type of geometric isomerism where compounds with the same molecular formula have different spatial arrangements of atoms. This occurs in alkenes and cyclic compounds where restricted rotation around a double bond or ring structure leads to distinct configurations. In cis isomers, similar groups are on the same side, while in trans isomers, they are on opposite sides.

Criteria for Cis-Trans Isomerism

For a compound to exhibit cis-trans isomerism, it must have a double bond or a ring structure that prevents free rotation. Additionally, the compound must have two different substituents attached to the carbon atoms involved in the double bond or the ring. If these conditions are met, the compound can exist in both cis and trans forms, which can significantly affect its physical and chemical properties.

Condensed Structural Formula

A condensed structural formula is a way of representing a chemical structure that shows the arrangement of atoms in a molecule without depicting all the bonds explicitly. It provides a simplified view of the molecule, indicating how atoms are connected. For cis-trans isomers, drawing the condensed structure helps visualize the differences in spatial arrangement, which is crucial for understanding their distinct properties.