Click on any peak for help in interpreting this spectrum.
The peak is a singlet, indicating that it corresponds to a carbon bearing no hydrogens. The chemical shift (d 197) suggests that the carbon is a carbonyl, most likely an aldehyde or ketone.
There are four peaks in this group; a singlet and three doublets. The chemical shift (d 128137) is in the region often observed for aromatic carbons. The fact that there are four peaks, and only one singlet, gives information regarding substitution on the ring.
The peak is a quartet, indicating that it corresponds to a CH3. The chemical shift (d 27) is in the region often observed for carbons adjacent to mildly electronegative groups, such as carbonyls.
C8H8O
From the molecular formula, the compound has "5 degrees of unsaturation" (5 double bonds or rings).
IUPAC Name: acetophenone
The 13C NMR has 6 peaks, a quartet at d 27 (a CH3), three doublets (CH groups), at d129, 128 and 133, and two singlets, one at d 137 and one at d 197. Since the molecule has eight carbons and six 13C NMR peaks, there must some degree of symmetry. The singlet at d 197 is in the carbonyl region, most likely an aldehyde or ketone. The CH3 groups at d 27 is consistent with a simple terminal methyl group, slightly shifted by an mildly electronegative group (a carbonyl?). The doublets at d 129, 128 and 133 and the singlet at d137 are in the aromatic region, suggesting a monosubstituted aromatic group, with symmetry in four of the six carbons.
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Structure: 