The Effect of Fluorine Substituents on 31P Chemical Shifts

31P is an NMR active nucleus with a nuclear spin of 1/% Its sensitivity (relative to H) is only 0.066, but because of its 100% natural abundance, the overall relative sensitivity of 31P is about 375 times that of 13 C. Thus, acquisition of phosphorous NMR spectra is relatively easy. The internal standard generally used for measuring 31P chemical shifts is 85% H3PO4. 

For those examples of phosphorous-containing compounds included in this book, 31P NMR data will be reported, when available. 

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