So Cliffnotes, DEPT really simplifies peak assignments for 13C spectra:ġ) CH – positive in DEPT-45, DEPT-90 and DEPT-135Ģ) CH2 – positive in DEPT-45, negative in DEPT-135, not observed in DEPT-90ģ) CH3 – positive in DEPT-45 and 135, and are silent in DEPT-90.ĭEPT is a great tool to add to your structural elucidation/peak assignment tool box! Happy structure elucidating! Finally, the DEPT-135 obviously distinguishes between the –CH2– (61.63 ppm) and –CH3 (14.14 ppm) of the ethyl chain. There are only 2 peaks in the DEPT-90 spectrum – so we can easily assign the quaternary aromatic-C (132.41 ppm)) and the primary aromatic-C’s (131.61 & 129.03 ppm). The suffix of the name reflects the type (s) of functional group (s. In general, the base part of the name reflects the number of carbons in what you have assigned to be the parent chain. These names are listed within the discussion of naming alkanes. In the DEPT-45 there are only 4 peaks (suggesting two quaternary and 4 with attached protons). In order to name organic compounds you must first memorize a few basic names. This results in a sensitivity enhancement relative to the standard decoupled 1D carbon spectra (13C spectrum there are 6 carbon peaks (δ 167.35, 132.41, 131.61, 129.03, 61.63 and 14.14 ppm) as we would expect given the top/bottom symmetry in diethyl phthalate. Distortionless Enhancement by Polarization Transfer (DEPT) is a double resonance pulse program that transfers polarization from an excited nucleus to another – most commonly 1H → 13C.