Question

Question: With reference to cation B, label each species as an isomer, a resonance structure, or neither

Short answer

Answer

a. The given structure is an isomer with reference to cation B.

b. The given structure is a resonance structure with reference to cation B.

c. The given structure is an isomer with reference to cation B.

d. The given structure is an isomer nor a resonance structure.

Step-by-step solution

Step-by-Step SolutionStep 1: Comparison of resonance structures with the isomers

The atoms are placed in distinct locations while considering the isomers. In the case of resonance structures, the electrons are situated at distinct locations

Comparison of compound B with compound a

Comparison of cation B with compound a

Both the structures given above contain two carbon-carbon double bonds and a positive charge. The carbon-carbon double bond does not conjugate the two structures.

The number of carbon atoms and the number of hydrogen atoms are the same in both structures. Hence, the given structures are isomers.

Comparison of compound B with compound b

Comparison of cation B with compound b

Both the structures given above contain two double bonds and one positive charge species. The structures are conjugated by double bonds. The number of carbon and hydrogen atoms in both structures is the same.

The phenomenon of resonance takes place, and hence, these two structures are resonance structures.

The shift of bonds can be shown in the following manner:

Representation of the resonance structures

 Step 4: Comparison of compound B with compound c

Comparison of cation B with compound c

Both the structures given above contain two double bonds and one positive charge. These structures are not conjugated by a carbon-carbon double bond. The number of carbon and hydrogen atoms in both structures is the same.

The two structures will have the same number of atoms in the molecular formula. Hence, these structures can be considered as isomers.

 Step 5: Comparison of compound B with compound d

Comparison of cation B with compound a

The analysis of cation B with compound d shows that species d has three double bonds and one positive charge. In the case of cation B, the number of double bonds is two, and the number of positive charges is one.

The number of carbon atoms and hydrogen atoms is different in both structures. Hence, these species are neither isomers nor resonance structures.