In 1H NMR, signal splitting (multiplicity) arises from spin-spin coupling between a proton and the nonequivalent protons on adjacent carbons, and is predicted by the n+1 rule: a signal splits into n+1 peaks, where n is the number of protons on directly neighboring carbon(s), with peak intensities forming a symmetrical pattern about the signal's center. Chemically equivalent protons do not split one another, and protons with zero neighboring protons appear as singlets. This concept belongs to organic chemistry / spectroscopic structure elucidation and forms one of the three interdependent pillars—alongside signal count (proton equivalence) and integration (relative proton count)—used to fully interpret a 1H NMR spectrum.
In 1H NMR, signal splitting (multiplicity) arises from spin-spin coupling between a proton and the nonequivalent protons on adjacent carbons, and is predicted by the n+1 rule: a signal splits into n+…