In a DEPT experiment, methyl, methylene, and methyne protons can be discriminated. There are several variations on the experiment. In one form, three spectra are produced. The first contains only methyl carbons, the second contains only methylene carbons, and the third contains only methyne carbons. In a second form, only one spectrum is produced where methyl and methyne carbons appear as positive peaks and methylene carbons appear as negative peaks.
Figure 37 shows the normal carbon-13 spectrum for citronellol. The assignment of peaks to particular carbon atoms is difficult because multiplicity information was lost during the proton decoupled experiment.
Figure 37. NMR spectra for citronellol.
Figure 38 shows the DEPT spectrum for citronellol. The assignment of peaks is much simpler because the methyl and methyne peaks are positive while the methylene peaks are negative.
Figure 38. DEPT spectra for citronellol.
Return to: NMR Spectroscopy Page