Chapter 16, Problem 16.41P

Interpretation Introduction

Interpretation:

${\text{Cyclohexane-d}}_{\text{11}}\left({\text{C}}_{\text{6}}{\text{HD}}_{\text{11}}\right)$ exhibits one signal in its ${}^{\text{1}}\text{H}$ NMR spectrum at room temperature whereas two signals appear in the spectrum when the temperature is lowered significantly.

Concept introduction:

The protons in different chemical environments interchange rapidly, and then they give rise to the same NMR signal that reflects the average of those environments. To cause the NMR lines to be broadened, the NMR time scale of the interchange must be slow enough or fast enough. NMR time scale is the time scale where the broadening occurs.