Carbon-13 NMR
An NMR technique that detects the carbon-13 nucleus to reveal the carbon skeleton of a molecule.
Formula / equation
δ 0–220 ppm
Unit
ppm
In depth
Only 1.1% of natural carbon is the magnetically active isotope, so the signals are weak and require many scans. Spectra are usually proton-decoupled, giving one sharp singlet per distinct carbon environment, which makes counting inequivalent carbons straightforward.
Examples in the real world
A carbonyl carbon appearing near 200 ppm; aromatic carbons clustering between 120 and 150 ppm.