Phosphorus-31 nuclear magnetic resonance
= Phosphorus-31 nuclear magnetic resonance
{title2=$^{31}\mathrm P\ \mathrm{NMR}$}
<Phosphorus-31 nuclear magnetic resonance> observes spin-one-half phosphorus-31. An $A_2X$ system can show a two-phosphorus doublet and a one-phosphorus triplet; three inequivalent mutually coupled phosphorus sites can each give a doublet of doublets in the first-order limit.