Click on any peak for help in interpreting this spectrum.
The peak is a "messy singlet", area 5, and is in the aromatic region, suggesting the presence of a mono-substituted benzene derivative.
The peak is a quartet, area 4, indicating that it corresponds to two identical CH2 groups adjacent to identical CH3 groups. The chemical shift (d 4.1) suggests that the groups are adjacent to an electronegative atom (i.e., oxygen).
The peak is a triplet, area 1, indicating that it corresponds to a CH group adjacent to a CH2 group. The chemical shift (d 3.7) suggests that the CH is adjacent to an electronegative atom (i.e., oxygen).
The peak is a doublet, area 2, indicating that it corresponds to a CH2 group adjacent to a CH. The chemical shift (d 2.8) suggests that the CH is adjacent to an electronegative group.
The peak is a triplet, area 6, indicating that it corresponds to six identical hydrogens (two CH3 groups) adjacent to two hydrogens. The chemical shift (d 1.2) is in the "simple alkane" region.
The peak is a quartet, indicating that it corresponds to a methyl group. The chemical shift (d 14) is in the "simple alkane" region.
The peak is a triplet, indicating that it corresponds to a CH2. The chemical shift (d 35.7) suggests that the CH is adjacent to a mild electron-withdrawing group.
The peak is a doublet, indicating that it corresponds to a CH. The chemical shift (d 57.8) suggests that the CH is adjacent to one or more electron-withdrawing groups.
The peak is a doublet, indicating that it corresponds to a CH2. The chemical shift (d 59.5) suggests that the CH2 is adjacent to an electron-withdrawing groups, such as oxygen.
The peaks are in the aromatic region (d 141.1, 125.3, 127.6, and 128.7). The presence of one singlet and three doublets suggests mono-substitution.
The peak is a singlet, indicating that it corresponds to a carbon bearing no hydrogens. The chemical shift (d 174) is in the carbonyl region, suggesting an acid or ester carbonyl.
The spectrum seems to be consistent with a simple carbonyl compound which may be aromatic, although the sp2 CH and C=C stretching bands are weak.
From the molecular formula, the compound has "six degrees of unsaturation" (six double bonds, carbonyls or rings). The large number suggests the presence of an aromatic ring (DU = 4).
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Structure:
The 13C spectrum contains nine peaks, indicating that the molecule has some elements of symmetry. The quartet at d 14 and the triplet at d 60 represent a simple CH3 and a CH2 which is deshielded by an electronegative atom (most likely oxygen); the doublet at d> 58 and the triplet at d> 36 are CH and CH2 groups which are adjacent to one or more electronegative groups. The peaks at d 141 - 125 are in the aromatic region; the fact that three doublets and one singlet are observed strongly suggests monosubstitution.
3400 cm-1:
no OH or NH present
3100 cm-1:
weak peak to suggest sp2 CH 2900 cm-1:
strong peak indicating sp3 CH
2200 cm-1:
no unsymmetrical triple bonds 1710 cm-1:
strong carbonyl absorbance
1610 cm-1:
weak peaks possibly suggesting Ar C=C
Click on any numbered peak for help in interpreting this spectrum.
The peak occurs at m/e = 91, and it is the base peak in this spectrum (the most intense peak). The molecular weight, m/e = 91, is a common fragment seen when a benzyl group is present (a tropylium ion).
The peak occurs at m/e = 131, making this peak m-119.
The peak occurs at m/e = 176, making this peak m-74.
The peak occurs at m/e = 205, making this peak m-45 (commonly, loss of a ethoxy).
The peak occurs at m/e = 250, which is the molecular weight of the compound, making this the molecular ion (m.+).
The mass spectrum consists of a molecular ion at 250, a base peak at 91 (a benzyl group), an m-45 peak at 205, indicating the presence of an ethoxy group; other significant peaks at 131 and 176 must be consistent with the proposed structure. The spectrum is consistent with a molecule containing ethoxy and benzyl groups.
C14H18O4; MW = 250.29
The proton NMR has a coupled quartet and a triplet, consistent with an ethyl group in which the CH2 (at d 4.1) is adjacent to an electronegative atom (most likely oxygen). The presence of a coupled triplet and doublet suggests the presence of a CH-CH2- group in which both carbons are adjacent to one or more electronegative atoms. The singlet at d 7.1 is consistent with a monosubstituted aromatic compound.
IUPAC Name: ethyl ethyl benzylpropanedioate (diethyl benzylmalonate)
13C NMR: 
MS: 