What does the "chemical shift" term mean in the NMR spectrum?

1 Answer
Jun 13, 2018

An old story....

Explanation:

In NMR spectroscopy we often use a material that gives a specific resonance frequency as a reference for the resonance frequencies of unknown materials.

And we look at the defining equation....

delta_"chemical shift"=(nu_"sample"-nu_"reference")/(nu_"reference")

Now the numerator thus has units of Hz...the denominator has units of MHz-=10^6*Hz...

...and thus we get the QUOTIENT...(Hz)/(MHz)=s^-1/(s^-1xx10^6)=1/1000000=1*"part per million"