Chapter 16, Problem 16.55P

Interpretation Introduction

Interpretation:

Both $\text{1, 4-dimethylbenzene}$ and $\text{1, 3, 5-trimethylbenzene}$ produce a ${}^{\text{1}}\text{H}$ NMR spectrum that has two signals. Which spectrum has the signal integrations in $1:3$ ratio is to be predicted.

Concept introduction:

The integration is the measurement of area under the absorption peak in NMR spectrum. This is proportional to the number of protons contributes to generate respective signal. The integration can be displayed as an integral trace superimposed on the spectrum. The integral trace for a single peak resembles a stair step, and the height of that stair step is proportional to the total area under the peak. The greater the height of integral stair trace, greater the number of protons that contribute to that signal. The area under an absorption peak is proportional to the number of protons that produce that peak.