Counting environments for carbon
13C NMR spectra show signals due to absorptions by the carbons in the molecule.
The number of signals depends on the number of environments for carbon in the molecule.
Every nonequivalent carbon in a molecule gives rise to a signal in the 13C spectrum.
Note that carbons may be equivalent
Test yourself:
Identify the number of nonequivalent carbons in each molecules below.
Check yourself:
Tap each image to see if you are right.
The number of signals depends on the number of environments for carbon in the molecule.
The different environments are due to the differing extent to which electrons around each carbon nucleus shield it from the magnetic field.
Every nonequivalent carbon in a molecule gives rise to a signal in the 13C spectrum.
Note that carbons may be equivalent
due to symmetry in the molecule (total or partial).
Test yourself:
Identify the number of nonequivalent carbons in each molecules below.
Check yourself:
Tap each image to see if you are right.
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