3. Carbon NMR spectra constants 13C

The chemical shifts δ (in ppm) of the carbons ¹³ C are given here, as for the proton ¹ H, in 3 forms: graphs, data tables and empirical formulas.

In the case of aliphatic derivatives, the major effects are due to the intensity of inductive effects.

For ethylenic and aromatic derivatives, the carbon most sensitive to the inductive effect is the one bearing the substituent. For other carbons, the major effects are due to the mesomeric effect of the substituent.

Finally, acetylenic carbons are relatively insensitive to the effects of substituents.

Stereochemistry plays a significant role, in particular due to steric effects.