Carbon Bonded to Nitrogen or Oxygen

The charge-shift correlations for carbon atoms bonded to nitrogen or oxygen are described by Eq. (6.9), namely 

For the C—N bonds of amines, the analysis presented in Section 15.1 validates this result with the usual reference values =35.1 me and 5 = 5.8 ppm from TMS, which are exactly those of the paraffins. The presence of nitrogen next to carbon does not seem to require any ad hoc revision this is certainly an acceptable approximation [139], at least within the limits of the energy calculations involved in this evaluation. 

The carbons of the alcohols are calculated just like those of the ethers. 

Intereshngly, the comparison of the carbonyl-NMR shifts with their net charges (Table 6.4, Fig. 6.5) indicates the same trend as that observed for the sp carbon atoms in paraffins, namely, a high-held shift with increasing positive net charge. 

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