Download a guide to 1h nmr chemical shift values

A GUIDE TO H NMR CHEMICAL SHIFT VALUES
1
Nuclear Magnetic Resonance (NMR) is a commonly used technique for organic compound structure determination. In 1H NMR, applying an external
magnetic field causes the nuclei spin to flip. The environment of the proton in the molecule affects where the signal is seen on the resultant spectrum.
O
R
H
Ar
C
O
C
C
R
R
H
CARBOXYLIC ACID
AROMATIC
H
H
R
R
C
O
VINYLIC
ETHER
C
Ar
R
O
C
H
PHENOLIC
O
Key
C
R
Ar
= Aromatic ring
R
= Rest of organic molecule
X
= Halogen atom
H
= Hydrogens producing signal
C
H
N
C
R
R
R
AMIDE
C
12.0
11.5
11.0
10.5
H
C
X
H
C
R
R
VINYLIC
C
R
H
R
H
H
KETONE
2˚ ALKYL
H
H
R
O
C
C
C
R
H
H
C
R
ALCOHOL
R
O
H
R
C
H
H
R
ACETYLENIC
H
ALLYLIC
1˚ ALKYL
H
R
N
H
ALCOHOL HYDROXYL (0.5-5.0) OR AMINO (1.0-4.0)
CHEMICAL SHIFT (δ, ppm)
12.5
3˚ ALKYL
H
Note these are typical values only, and vary depending on the
solvent, the temperature, and presence of other functional groups.
13.0
BENZYLIC
C
H
R
H
H
H
C
O
ALKYL HALIDE
R
R
R
H
ALDEHYDE
H
H
H
H
H
C
Ar
H
O
R
H
R
10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
TMS
1.0
0.5
0
SPIN-SPIN COUPLING PATTERNS IN NMR SPECTR A
Hydrogen nuclei themselves possess a small magnetic field, and can
influence the signal seen for hydrogens on neighbouring carbon atoms.
This is known as spin-spin coupling. The number of signals the original
signal is split into is equal to the number of hydrogens on neighbouring
carbon atoms plus one, according to the patterns shown to the left. The
area underneath the peaks indicates the number of hydrogen atoms
responsible for each signal.
C
1
1:1
1:2:1
1:3:3:1
1:4:6:4:1
1:5:10:10:5:1
1:6:15:20:15:6:1
QUINTET
SEXTET
SEPTET
OCTET
NONET
4 adj H
5 adj H
6 adj H
7 adj H
8 adj H
SINGLET
DOUBLET
TRIPLET
QUARTET
0 adj H
1 adj H
2 adj H
3 adj H
1:7:21:35:35:21:7:1 1:8:28:56:70:56:28:8:1
NUMBER OF HYDROGENS ON ADJACENT CARBON ATOMS
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