Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Phosphorus-31 NMR

Phosphorus-31 NMR (for nuclear magnetic resonance) is an analytical technique. It is one of the more routine NMR techniques because 31P has an isotopic abundance of 100% and a relatively high magnetogyric ratio. The 31P nucleus also has a spin of ½, making spectra relatively easy to obtain and interpret. Due to the inconsistent nuclear Overhauser effect, integrations are not useful.

Phosphorus is commonly found in organic compounds and coordination complexes (as phosphines), making it useful to measure 31P NMR spectra routinely.

85% phosphoric acid is conventionally used as an external standard.