Q.7. - Organic Chemistry

Question

Question: How many ${}^{\mathbf{13}}\mathit{C}$  NMR signals do each compound exhibit?  

a. 

b.

c.

Step-by-Step Solution

Answer

Answer

 

Number of ${}^{13}C$ NMR signals

 

1. 6 signals
2. 7 signals
3. 4 signals

Step 1: C 13 NMR

The ${}^{\mathbf{13}}\mathit{C}$ has an odd number of neutrons and hence exhibits the NMR phenomenon. It is used to understand the backbone of an organic molecule, to identify the number of equivalent carbon and types of carbons.

Step 2: Number of C 13 NMR signal

a. Six types of carbons are present in the structure which are represented as: 

Equivalent carbon in structures 

Therefore, the compound gives 6 signals.

b. All the carbons in the structure are non-equivalent because of different chemical environment.

Structure with no equivalent carbon 

Therefore, the compound gives 7 signals.

c. There are four sets of equivalent carbons which are represented as:

Equivalent carbon in structures

Therefore, the compound gives 4 signals.