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Confused about NMR spectroscopy..

If an unpaired nucleon is needed to produce the magnetic field necessary for NMR then doesn’t that mean that only isotopes can be analysed by NMR?
Original post by WoopWoop1212
If an unpaired nucleon is needed to produce the magnetic field necessary for NMR then doesn’t that mean that only isotopes can be analysed by NMR?


Only specific isotopes.... every nucleus is an isotope of a particular element. You do know what an isotope is right? If the nucleus has a magnetic moment (which is why the number of nucleons must be odd as the cancel out) then it can be detected by NMR and is termed NMR active.
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Taimmi
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Original post by WoopWoop1212
If an unpaired nucleon is needed to produce the magnetic field necessary for NMR then doesn’t that mean that only isotopes can be analysed by NMR?


Isotopes can have paired or unpaired nucleons, just as normal elements can be paired or unpaired.

For example, water cannot be used as a solvent in proton NMR because H atoms are unpaired and so will produce a signal. For this reason deuterium, an isotope of hydrogen, is used in D20 as it does not produce a signal.
Original post by Taimmi
Isotopes can have paired or unpaired nucleons, just as normal elements can be paired or unpaired.

For example, water cannot be used as a solvent in proton NMR because H atoms are unpaired and so will produce a signal. For this reason deuterium, an isotope of hydrogen, is used in D20 as it does not produce a signal.


Sorry but D does have a nuclear spin, of 1 btw as opposed to 1/2 for a proton. It has a different resonance which it is used and because it is a quadrupolar nucleus it undergoes rapid relaxation so splitting is not typically observed.

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