Carbon Nuclear Magnetic Resonance (¹³C-NMR) Spectroscopy

Nuclear Magnetic Resonance (NMR) Spectroscopy is not limited to the study of protons. Any element with a nuclear spin (¹³C, ¹⁷O, ¹⁹F, ³¹P and many others) will give rise to an NMR signal.

Carbon-13 has a nuclear spin (I = ½) and makes up 1.1% of all naturally occurring carbon, a high enough abundance along with modern technology to make carbon nuclear magnetic resonance spectroscopy (¹³C-NMR) a useful technique. Since carbon is the element central to organic chemistry, ¹³C-NMR plays an important role in determining the structure of unknown organic molecules and the study of organic reactions and processes.

The idea and theory behind ¹³C-NMR is the same as with ¹H-NMR, just a different nucleus, so you really do not have to learn anything new to understand and interpret ¹³C-NMR's to help you solve structures of unknown organic compounds.

In particular, the¹³C-NMR spectrum of an organic compound provides information concerning:

• the # of different types of carbon atoms present in the molecule
• the electronic environment of the different types of carbons
• the number of "neighbors" a carbon has (splitting)

The major differences that you will notice in ¹³C-NMR in comparison to ¹H-NMR spectra include:

• No integration of carbon spectra
• Wide range (0-200 ppm) of resonances for common carbon atoms (typical range for protons 1-10 ppm)

Use the index on the left to choose which topic you want to go.
If you are pretty good at interpreting ¹³C-NMR, you may want to go straight to the exercises. If not, maybe you could visit the tutorial pages and take the included quizzes.