How Proton NMR Separates Similar Hydrogens

Proton NMR can show whether similar hydrogens are truly equivalent or not. The key idea is that the local environment around each hydrogen affects its chemical shift. In some molecules, two hydrogens give one signal. In others, they appear at slightly different positions.

In chloroethane, replaci...

In chloroethane, the alpha-hydrogens produce an enantiomeric pair upon replacement.

These enantiotopic protons are related by a mirror plane and produce identical chemical shifts in an achiral environment. Because proton NMR spectra are typically recorded using achiral solvents, enantiotopic protons yield the same signal as each other in ...