Click on any peak for help in interpreting this spectrum.
The peak is a singlet, area 5. The chemical shift (d 7.2) is in the aromatic region, suggesting the presence of a mono-substituted aromatic. Recall that, at low resolution, mono-substituted aromatics often generate a singlet in this region, even though there are three different types of ring hydrogens.
This is best described as a multiplet, area 1, indicating that it corresponds to a hydrogen which is coupled to more than one neighboring hydrogen. The chemical shift (d 5.7) is in the alkene region, suggesting that this is a =CH- which is coupled to other alkene hydrogens.
This is best described as a pair of multiplets, area 1 each, indicating that they corresponds to hydrogens which are coupled to more than one neighboring hydrogen. The chemical shifts (d 5.1 and 4.9) re in the alkene region, suggesting that they represent a =CH2 which where each hydrogen coupled to another alkene hydrogen.
The peak is a doublet, area 2, indicating that it corresponds to a CH2 group which is adjacent to one hydrogen. The chemical shift (d 3.1) suggests the CH2 is adjacent to an electronegative group.
The peak is a triplet, indicating that it corresponds to a CH2 group. The chemical shift (d 44.9) suggests the CH2 is adjacent to one or more electronegative groups.
These peak are in the "alkene region". The peak at d 115 is a triplet, indicating that it corresponds to a CH2 and the peak at 137 is a doublet, which corresponds to a CH, suggesting a terminal alkene, -CH=CH2.
These peaks are in the "aromatic region". The fact that there is one singlet and three doublets strongly suggests that this represents a mono-substituted benzene derivative.
The spectrum seems to be consistent with a simple alkene.
From the molecular formula, the compound has "five 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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The 13C spectrum contains seven peaks, indicating that the molecule has some elements of symmetry. The triplet at d 45 represents a CH2 which is deshielded by adjacent electronegative groups. The peaks at d 140 - 126 are in the aromatic region; the fact that three doublets are observed strongly suggests monosubstitution. The peaks at d 138 and 115 are in the double bond region and, from the splitting, most likely represent a terminal alkene.
3400 cm-1:
no OH or NH present
3100 cm-1:
sharp peak suggesting sp2 CH 2900 cm-1:
weak peak indicating sp3 CH
2200 cm-1:
no unsymmetrical triple bonds 1710 cm-1:
no carbonyl absorbance
1640 cm-1:
sharp peak suggesting C=C
Click on any numbered peak for help in interpreting this spectrum.
The peak occurs at m/e = 91, making this peak m-27. The molecular weight of the fragment corresponds to the benzyl (or tropylium) cation radical.
The peak occurs at m/e = 117, and it is the base peak in this spectrum (the most intense peak). The fragmentation is m-1, which is commonly seen in alcohols, aldehydes, and in compounds which can loose a hydrogen to form a resonance-stabilized cation radical.
The peak occurs at m/e = 118, which is the molecular weight of the compound, making this the molecular ion (m.+).
The peak occurs at m/e = 87, making this peak m-1 (loss of a hydrogen). Loss of a m/e = 1 is often seen in compounds with acidic hydrogens.
The mass spectrum consists of a molecular ion at 118, and a m-1 peak at 117. The peak at 91 is of moderate intensity and most likely represents a benzyl unit. The spectrum is consistent with a molecule which contains a benzyl unit and can lose one hydrogen to form a stable cation.
C9H10; MW = 118.18
The proton NMR has a doublet at d 3.1 (2H), a singlet at d 7.2 (5H) and two groups of multiplets at d 5 - 6 (1H and 2H). The singlet in the aromatic region strongly suggest monosubstitution; the peak at d 3.26 must represent a CH2 which is somewhat deshielded, perhaps flanked by electron withdrawing groups. The multiplets are in the alkene region and most likely represent the "ABC" pattern observed for terminal alkenes.
IUPAC Name: 2-propenyl benzene (allyl benzene)
13C NMR: 
MS: 