spin-spin splitting

In nuclear magnetic resonance (NMR) spectroscopy, spin-spin splitting refers to the interaction between the spins of adjacent atomic nuclei. This interaction causes the splitting of NMR spectral lines into multiple components, providing valuable information about the connectivity of atoms within a molecule.1

This splitting occurs because the magnetic field experienced by a nucleus is influenced by the spin states of neighboring nuclei. The number of lines a signal is split into typically corresponds to the number of equivalent neighboring nuclei plus one, following the n+1 rule for simple cases. For instance, a proton nucleus with one neighboring proton would show a doublet, while a proton with two neighboring protons would appear as a triplet.1

While spin-spin splitting is a crucial tool in proton NMR, it is often less pronounced or removed in other NMR techniques, such as carbon-13 NMR, due to factors like the low natural abundance of the 13C isotope or the use of proton decoupling techniques.2