Infrared Spectra Chart (Stretching Vibrations)

Front 1

C-H

Back 1

3000-2850
Saturated alkanes, limited value as most organic compounds contain C-H

Front 2

=C-H

Back 2

3100-3000
Unsaturated alkene or aromatic

Front 3

=_C-H

Back 3

3300
Terminal Alkyne

Front 4

O=C-H
aldehyde; 2 peaks

Back 4

2800-2700

Front 5

O-H

O-H (free)

Back 5

3400-300
3600
alcohols and phenols. if hydrogen bonding present peak will be broad 300-2500 (ex. carboxylic acids)

Front 6

N-H

Back 6

3450-3100
Amines: primary- several peaks, secondary- one peak
tertiary- no peaks

Front 7

C=C

Back 7

1675-1600
Often weak

Front 8

C=N

Back 8

1690-1630
often difficult to assign

Front 9

N=O
nitro compounds

Back 9

1560-1510 & 1370-1330

Front 10

C_=C
alkynes; bands are weak

Back 10

2260-2120

Front 11

C-=N
nitriles

Back 11

2260-2220

Front 12

C-C

Back 12

variable
no diagnostic value

Front 13

C-O, C-N

Back 13

1400-1000

Front 14

C-Cl

Back 14

800-700
Difficult to interpret

Front 15

C-Br; C-I

Back 15

Below 650
Often out of range of intrumentation

Front 16

C=O (anhydrides)

Back 16

1840-1800 &1780-1740

Front 17

C=O (acyl halides)

Back 17

1815-1760

Front 18

C=O (esters)

Back 18

1750-1715
sat = 1735
vinylic or benzylic = 1715

Front 19

C=O (aldehydes)

Back 19

1740 - 1680
sat. =1730
vinylic/benzylic = 1705

Front 20

C=O (ketones)

Back 20

sat./ 6-mem cyclic = 1715
5-memeber cyclic= 1750
vinylic or next to aromatic = 1690

Front 21

C=O (carboxylic acids)

Back 21

1720-1670

Front 22

C=O (amides)

Back 22

1690-1630