Chapter 14, Problem 10PP

Interpretation Introduction

Interpretation:

The ${}^{\text{13}}\text{C}\text{NMR}$ signals are to be predicted for the various given aromatic compounds.

Concept introduction:

Carbon nuclear magnetic resonance ${(}^{\text{13}}\text{C}\text{NMR)}$ is considered homologous to proton nuclear magnetic resonance ${(}^{\text{1}}\text{H}\text{NMR)}$.

In $\text{NMR}$ spectroscopy, the proton and ¹³C nuclear magnetic resonance ${(}^{\text{1}}\text{H}\text{NMR)}$ is used to find out the structure of molecules.

The splitting of the molecules is determined by the (2nI+1) rule. For ¹H, I= ½, hence 2nI+1 = n+1, which dictates the splitting pattern. where, $\text{n}$ is the number of hydrogens on the adjacent atom.

For ¹³C NMR, generally we plot the proton decoupled spectrum and hence it comes as single sharp singlet lines. The number of peaks correspond to the number of equivalent carbon atoms in the molecule.