Carbon-13 NMR Spectroscopy

Carbon-13 NMR Spectroscopy

Almost all carbon atoms are carbon-12 with just a small proportion being Carbon-13.

Carbon-13 has an odd number of nucleons (13) resulting in a residual magnetic spin.

Chemical Shift

• is a scale that compares the frequency of an NMR absorption
• with the frequency of the reference peak of TMS at 0ppm

Chemical shifts indicate the chemical environments of the carbon atoms present. The presence of an electronegative atom causes a significant chemical shift.

A…