What is Spin-Spin Coupling?
Spin-spin coupling is the interaction between the spin magnetic moments of different electrons and/or nuclei.
In NMR spectroscopy it gives rise to multiplet patterns, and cross-peaks in two-dimensional NMR spectra. Between electron and nuclear spins this is termed the nuclear hyperfine interaction. Between electron spins it gives rise to relaxation effects and splitting of the EPR spectrum.
