Chapter 16, Problem 16.10YT

Interpretation Introduction

Interpretation:

In Figure $\text{16-15}$, the proton(s) responsible for splitting the signal at $\text{4}\text{.0 ppm}$ is to be circled, and the proton(s) responsible for splitting the signal at $\text{5}\text{.8 ppm }$ is to be boxed.

Concept introduction:

This signal splitting occurs because every proton behaves like a tiny bar magnet that can be in either the $\text{α}$ state or the $\text{β}$ state. The magnetic field that any particular proton experiences (i.e., ${\text{B}}_{\text{eff}}$) can therefore be altered by the magnetic fields of nearby protons, and these alterations can affect the proton’s apparent chemical shift. The protons are said to interact with each other through spin-spin coupling, and the protons involved are said to be coupled to each other. In general, the protons that are coupled are chemically distinct from each other and are generally separated by three or fewer single bonds.