NMR Chemical Shifts of Impurities Charts

Using NMR Chemical Impurities Tables

These tables can support you in identifying and separating NMR signals of impurities that might originate from residual solvents or from your reaction apparatus. Here we present the NMR shifts of the most commonly used solvents and impurities in organic synthesis measured in the 7 most frequently used deuterated solvents. Please note that the values given in the tables are temperature- and partly concentration-dependent and therefore represent average values only. The 1H-NMR data were obtained using a 300 MHz spectrometer, the 13C-NMR data using 75 MHz.

1H NMR Chemical Impurity Shifts Table

   proton    mult    CDCl3    (CD3)2CO  (CD3)2SO   C6D6    CD3CN    CD3OD    D2
Solvent
residual
peak
    7.26 2.05 2.50 7.16 1.94 3.31 4.79
H2O   s 1.56 2.84 3.33 0.40 2.13 4.87  
Acetic acid CH3 s 2.10 1.96 1.91 1.55 1.96 1.99 2.08
Acetone CH3 s 2.17 2.09 2.09 1.55 2.08 2.15 2.22
Acetonitrile CH3 s 2.10 2.05 2.07 1.55 1.96 2.03 2.06
Benzene CH s 7.36 7.36 7.37 7.15 7.37 7.33  
Tert-butyl
alcohol
CH3
OH
s
s
1.28 1.18 1.11
4.19
1.05
1.55
1.16
2.18
1.40 1.24
Tert-butyl
methyl
ether
CCH3
OCH3
s
s
1.19
3.22
1.13
3.13
1.11
3.08
1.07
3.04
1.14
3.13
1.15
3.20
1.21
3.22
BHTa ArH
OH
ArCH3 ArC(CH3)3
s
s
s
s
6.98 5.01 2.27 1.43 6.96

2.22
1.41
6.87
6.65
2.18
1.36
7.05 4.79 2.24 1.38 6.97
5.20
2.22
1.39
6.92

2.21
1.40
 
Chloroform CH s 7.26 8.02 8.32 6.15 7.58 7.90  
Cyclohexane CH2 s 1.43 1.43 1.40 1.40 1.44 1.45  
1,2-dichloro-
ethane
CH2 s 3.73 3.87 3.90 2.90 3.81 3.78  
Dichloro-
methane
CH2 s 5.30 5.63 5.76 4.27 5.44 5.49  
Diethyl ether CH3
CH2
t, 7
q, 7
1.21
3.48
1.11
3.41
1.09
3.38
1.11
3.26
1.12
3.42
1.18
3.49
1.17
3.56
Diglyme CH2
CH2
OCH3
m
m
s
3.65
3.57
3.39
3.56
3.47
3.28
3.51
3.38
3.24
3.46
3.34
3.11
3.53
3.45
3.29
3.61
3.58
3.35
3.67
3.61
3.37
1,2-dimeth-
oxyethane
CH3
CH2
s
s
3.40
3.55
3.28
3.46
3.24
3.43
3.12
3.33
3.28
3.45
3.35
3.52
3.37
3.60
Dimethyl-
acetamide
CH3CO
NCH3
NCH3
s
s
s
2.09
3.02
2.94
1.97
3.00
2.83
1.96
2.94
2.78
1.60
2.57
2.05
1.97
2.96
2.83
2.07
3.31
2.92
2.08
3.06
2.90
Dimethyl-
formamide
CH
CH3
CH3
s
s
s
8.02
2.96
2.88
7.96
2.94
2.78
7.95
2.89
2.73
7.63
2.36
1.86
7.92
2.89
2.77
7.97
2.99
2.86
7.92
3.01
2.85
Dimethyl
sulfoxide
CH3 s 2.62 2.52 2.54 1.68 2.50 2.65 2.71
Dioxane CH2 s 3.71 3.59 3.57 3.35 3.60 3.66 3.75
Ethanol CH3
CH2
OH
t, 7
q, 7
s
1.25
3.72
1.32
1.12
3.57
3.39
1.06
3.44
4.63
0.96
3.34
1.12
3.54
2.47
1.19
3.60
1.17
3.65
Ethyl
acetate
CH3CO
CH2CH3
CH2CH3
s
q, 7
t, 7
2.05
4.12
1.26
1.97
4.05
1.20
1.99
4.03
1.17
1.65
3.89
0.92
1.97
4.06
1.20
2.01
4.09
1.24
2.07
4.14
1.24
Ethyl methyl
ketone
CH3CO
CH2CH3
CH2CH3
s
q, 7
t, 7
2.14
2.46
1.06
2.07
2.45
0.96
2.07
2.43
0.91
1.58
1.81
0.85
2.06
2.43
0.96
2.12
2.50
1.01
2.19
3.18
1.26
Ethylene
glycol
CH s 3.76 3.28 3.34 3.41 3.51 3.59 3.65
“Grease” CH3
CH2
m
br s
0.86 1.26 0.87
1.29
  0.92 1.36 0.86
1.27
0.88
1.29
 
   
N-hexane
CH3
CH2
t
m
0.88
1.26
0.88
1.28
0.86
1.25
0.89
1.24
0.89
1.28
0.90
1.29
 
HMPAb CH3 d,
9.5
2.65 2.59 2.53 2.40 2.57 2.64 2.61
Methanol CH3
OH
s
s
3.49
1.09
3.31
3.12
3.16
4.01
3.07 3.28
2.16
3.34 3.34
Nitromethane CH3 s 4.33 4.43 4.42 2.94 4.31 4.34 4.40
n-pentane CH3
CH2
t, 7
m
0.88
1.27
0.88
1.27
0.86
1.27
0.87
1.23
0.89
1.29
0.90
1.29
 
2-propanol CH3
CH
d, 6
sep,
6
1.22
4.04
1.10
3.90
1.04
3.78
0.95
3.67
1.09
3.87
1.50
3.92
1.17
4.02
Pyridine CH(2)
CH(3)
CH(4)
m
m
m
8.62
7.29
7.68
8.58
7.35
7.76
8.58
7.39
7.79
8.53
6.66
6.98
8.57
7.33
7.73
8.53
7.44
7.85
8.52
7.45
7.87
Silicone grease CH3 s 0.07 0.13   0.29 0.08 0.10  
Tetrahydro-
furan
CH2
CH2O
m
m
1.85
3.76
1.79
3.63
1.76
3.60
1.40
3.57
1.80
3.64
1.87
3.71
1.88
3.74
Toluene CH3
CH(o/p)
CH(m)
s
m
m
2.36
7.17
7.25
2.32
7.1 – 7.2
7.1 – 7.2
2.30
7.18
7.25
2.11
7.02
7.13
2.33
7.1 – 7.3
7.1 – 7.3
2.32
7.16
7.16
 
Triethyl-
amine
CH3
CH2
t, 7
q, 7
1.03
2.53
0.96
2.45
0.93
2.43
0.96
2.40
0.96
2.45
1.05
2.58
0.99
2.57
a 2,6-Dimethyl-4-tert-butylphenol
b Hexamethylphosophoramide

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13C NMR Chemical Impurity Shifts Table

  carbon CDCl3 (CD3)2CO (CD3)2SO C6D6 CD3CN  CD3OD  D2O
Solvent signals   77.16
± 0.06 29.84 ± 0.01
206.26 ± 0.13
39.52
± 0.06
128.06
±0.02
1.32 ± 0.02
118.26 ± 0.02
49.00
±0.01
Acetic acid CO
CH3
175.99
20.81
172.31
20.51
171.93
20.95
175.82
20.37
173.21
20.73
175.11
20.56
177.21
21.03
Acetone CO
CH3
207.07
30.92
205.87
30.60
206.31
30.56
204.43
30.14
207.43
30.91
209.67
30.67
215.94
30.89
Acetonitrile CN
CH3
116.43
1.89
117.60
1.12
117.91
1.03
116.02
0.20
118.26
1.79
118.06
0.85
119.68
1.47
Benzene CH 128.37 129.15 128.30 128.62 129.32 129.34  
Tert-butyl
alcohol
C
CH3
69.15
31.25
68.13
30.72
66.88
30.38
68.19
30.47
68.74
30.68
69.40
30.91
70.36
30.29
Tert-butyl
methyl
ether
CCH3
C
CCH3
49.45
72.87
26.99
49.35
72.81
27.24
48.70
72.04
26.79
49.19
72.40
27.09
49.52
73.17
27.28
49.66
74.32
27.22
49.37
75.62
26.60
BHT C(1)
C(2) CH(3) C(4)
CH3Ar CH3C
C
151.55 135.87 125.55 128.27 21.20 30.33 34.25 152.51
138.19
129.05
126.03
21.31
31.61
35.00
151.47
139.12
127.97
124.85
20.97
31.25
34.33
152.05
136.08
128.52 125.83
21.40 31.34
34.35 
152.42 138.13 129.61 126.38 21.23 31.50 35.05 152.85 139.09 129.49 126.11
21.38
31.15
35.36
 
Chloroform CH 77.36 79.19 79.16 77.79 79.17 79.44  
Cyclo-hexane CH2 26.94 27.51 26.33 27.23 27.63 27.96  
1,2-dichloroe-
thane
CH2 43.50 45.25 45.02 43.59 45.54 45.11  
Dichloro-methane CH2 53.52 54.95 54.84 53.46 55.32 54.78  
Diethyl ether CH3
CH2
15.20 65.91 15.78
66.12
15.12
62.05
15.46 65.94 15.63 66.32 15.46
66.88
14.77 66.42
Diglyme CH3
CH2
CH2
59.01
70.51
71.90
58.77
71.03
72.63
57.98
69.54
71.25
58.66
70.87
72.35
58.90
70.99
72.63
59.06
71.33
72.92
58.67
70.05
71.63
1,2-dimethoxy-
ethane
CH3
CH2
59.08
71.84
58.45
72.47
58.01
17.07
58.68
72.21
58.89
72.47
59.06
72.72
58.67
71.49
Dimethyl-acetamide CH3
CO
NCH3
NCH3
21.53 171.07 35.28 38.13 21.51
170.61
34.89
37.92
21.29
169.54
37.38
34.42
21.16 169.95 34.67 37.03 21.76 171.31 35.17 38.26 21.32
173.32
35.50
38.43
21.09 174.57 35.03 38.76
Dimethyl-formamide CH
CH3
CH3
162.62
36.50
31.45
162.79
36.15
31.03
162.29
35.73
30.73
162.13
35.25
30.72
163.31
36.57
31.32
164.73
36.89
31.61
165.53
37.54
32.03
Dimethyl
sulfoxide
CH3 40.76 41.23 40.45 40.03 41.31 40.45 39.39
Dioxane CH2 67.14 67.60 66.36 67.16 67.72 68.11 67.19
Ethanol CH3
CH2
18.41
58.28
18.89
57.72
18.51
56.07
18.72
57.86
18.80
57.96
18.40
58.26
17.47
58.05
Ethyl acetate CH3CO
CO
CH2
CH3
21.04 171.36 60.49 14.19 20.83
170.96
60.56
14.50
20.68
170.31
59.74
14.40
20.56 170.44 60.21 14.19 21.16 171.68 60.98 14.54 20.88
172.89
61.50
14.49
21.15 175.26 62.32 13.92
Ethyl methyl
ketone
CH3CO
CO
CH2CH3
CH2CH3
29.49
209.56
36.89
7.86
29.30
208.30
36.75
8.03
29.26
208.72
35.83
7.61
28.56
206.55
36.36
7.91
29.60
209.88
37.09
8.14
29.39
212.16
37.34
8.09
29.49
218.43
37.27
7.87
Ethylene glycol CH2 63.79 64.26 62.76 64.34 64.22 64.30 63.17
“Grease” CH2 29.76 30.73 29.20 30.21 30.86 31.29  
N-hexane CH3
CH2(2)
CH2(3)
14.14
22.70
31.64
14.34
23.28
32.30
13.88
22.05
30.95
14.32
23.04
31.96
14.43
23.40
32.36
14.45
23.68
32.73
 
HMPA CH3 36.87 37.04 36.42 36.88 37.10 37.00 36.46
Methanol CH3 50.41 49.77 48.59 49.97 49.90 49.86 49.50
Nitro-methane CH3 62.50 63.21 63.28 61.16 63.66 63.08 63.22
N-pentane CH3
CH2(2)
CH2(3)
14.08
22.38
34.16
14.29
22.98
34.83
13.28
21.70
33.48
14.25
22.72
34.45
14.37
23.08
34.89
14.39
23.38
35.30
 
2-propanol CH3
CH
25.14
64.50
25.67
63.85
25.43
64.92
25.18
64.23
25.55
64.30
25.27
64.71
24.38
64.88
Pyridine CH(2)
CH(3)
CH(4)
149.90
123.75
135.96
150.67
124.57
136.56
149.58
123.84
136.05
150.27
123.58
135.28
150.76
127.76
136.89
150.07
125.53
138.35
149.18
125.12
138.27
Silicone grease CH3 1.04 1.40   1.38   2.10  
Tetrahydro-furan CH2
CH2O
25.62
67.97
26.15
68.07
25.14
67.03
25.72
67.80
26.27
68.33
26.48
68.83
25.67
68.68
Toluene CH3
CH(i) CH(o) CH(m) CH(p)
21.46 137.89 129.07 128.26 125.33 21.46
138.48
129.76
129.03
126.12
20.99
137.35
128.88
128.18
125.29
21.10 137.91 129.33 128.56 125.68 21.50 138.90 129.94 129.23 126.28 21.50
138.85 129.91 129.20 126.29
 
Triethyl-amine CH3
CH2
11.61.
46.25
12.49
47.07
11.74
45.74
12.35
46.77
12.38
47.10
11.09
46.96
9.07
47.19

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References

H.E. Gottlieb, V. Kotlyar, A. Nudelman, J.Org.Chem. 1997, 62, 7512.