# Why does NMR deal with protons?

I ask this b/c I know the NMR deal with magnetic fields (MF) and it can change energy of proton’s magnetic energy. But my question is that electrons also have a spin and M F. Just like how IR and Mass deal with electrons, why don’t NMR also talk about electrons? Why just focus in the nucleus.

• The energy gap between "up" and "down" spin states of an electron is much larger than the energy gap between the two spin states of a proton. So, the spectra don't quite interfere. It is possible to do what is essentially NMR, but on an electron: en.wikipedia.org/wiki/Electron_paramagnetic_resonance – orthocresol Feb 10 '17 at 21:51
• Your question and title are inconsistent. All nuclei aren't just a proton. $\ce{^13C}$ is also used for NMR studies as well as other isotopes. – MaxW Feb 10 '17 at 21:52
• Electron spins are used for spectroscopy. The expected energy gap is different so you would be looking in a different area of the EM spectrum (i.e., microwave versus radio). See: en.wikipedia.org/wiki/Electron_paramagnetic_resonance – Zhe Feb 10 '17 at 23:07
• So can I know why electron spin are also not used to know a molecules structure in orgo? Why just focus on NMR? Does NMR have more usefulness? – TLo Feb 11 '17 at 0:12
• EPR only works for unpaired electrons. Most organic compounds have only paired electrons. Organometallic complexes are fairly rare in the overall scheme of things. – MaxW Feb 11 '17 at 2:56