For each set of isomers, choose the isomer that you expect to be most stable and the isomer you expect to be least stable.
(c)

Verified step by step guidance

Analyze the structures of the given isomers. Look for key factors that influence stability, such as the degree of substitution of carbons, resonance stabilization, steric hindrance, and hyperconjugation.

Evaluate the degree of substitution for each isomer. More substituted alkenes (e.g., tertiary > secondary > primary) are generally more stable due to hyperconjugation and inductive effects.

Check for resonance stabilization. Isomers with conjugated systems or resonance structures are typically more stable because delocalization of electrons lowers the overall energy of the molecule.

Assess steric hindrance in each isomer. Isomers with bulky groups in close proximity may experience destabilizing steric interactions, making them less stable.

Rank the isomers based on the above factors to determine which isomer is the most stable and which is the least stable. The most stable isomer will have the optimal combination of substitution, resonance, and minimal steric hindrance, while the least stable isomer will lack these stabilizing features.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Isomer Stability

Isomer stability refers to the relative energy levels of different isomers, which can be influenced by factors such as steric strain, torsional strain, and electronic effects. Generally, more stable isomers have lower energy due to minimized repulsions and favorable interactions. Understanding the stability of isomers is crucial for predicting their behavior in chemical reactions.

Steric Hindrance

Steric hindrance occurs when atoms or groups within a molecule are forced close together, leading to increased repulsion and instability. In isomers, bulky groups can create steric strain, making certain conformations less favorable. Recognizing steric hindrance helps in determining which isomer might be more or less stable based on the spatial arrangement of substituents.

Torsional Strain

Torsional strain arises from the eclipsing interactions between atoms or groups in a molecule when they are rotated around a bond. This strain is particularly relevant in cyclic compounds and can significantly affect the stability of isomers. Understanding torsional strain allows chemists to predict which conformations of isomers will be more stable based on their rotational barriers.

Recommended video:

Guided course