The carbon nucleus, like the hydrogen nucleus, can undergo nuclear magnetic resonance. Several differences include:
- Only the less abundant 13C nucleus (1.08% natural abundance) can undergo nuclear spin flip. Therefore,
the signal produced is very small, and acquisition of a spectrum takes quite a bit longer.
- The magnetogyric ratio of the 13C nucleus is smaller than that of the hydrogen nucleus, causing the
resonance frequency for 13C NMR to be much lower than in 1H NMR spectroscopy (15.1 MHz for
13C as opposed to 60 MHz for 1H in a 1.41 Tesla field).
- At these lower frequencies, the excess population of nuclei in the lower spin state is reduced, which, in turn,
reduces the sensitivity of NMR detection procedures.
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