IR Spectrum Table & Chart

The IR Spectrum Table is a chart for use during infrared spectroscopy. The table lists IR spectroscopy frequency ranges, appearance of the vibration and absorptions for functional groups. There are two tables grouped by frequency range and compound class.

IR Spectrum Table by Frequency Range

Use this table when you already know the frequency of your material. Find the frequency range in the first column on the left side of the chart and corresponding values in adjacent columns.

If you need to find the frequency of a material go to the IR table by compound.

 

Frequency Range Absorption (cm-1) Appearance Group Compound Class Comments
4000-3000 cm-1 3700-3584 medium, sharp O-H stretching alcohol free
  3550-3200 strong, broad O-H stretching alcohol intermolecular bonded
  3500 medium N-H stretching primary amine  
  3400        
  3400-3300 medium N-H stretching aliphatic primary amine  
  3330-3250        
  3350-3310 medium N-H stretching secondary amine  
  3300-2500 strong, broad O-H stretching carboxylic acid usually centered on 3000 cm-1
  3200-2700 weak, broad O-H stretching alcohol intramolecular bonded
  3000-2800 strong, broad N-H stretching amine salt  
3000-2500 cm-1          
3000-2500 cm-1 3333-3267 strong, sharp C-H stretching alkyne  
  3100-3000 medium C-H stretching alkene  
  3000-2840 medium C-H stretching alkane  
  2830-2695 medium C-H stretching aldehyde doublet
  2600-2550 weak S-H stretching thiol  
2400-2000 cm-1          
2400-2000 cm-1 2349 strong O=C=O stretching carbon dioxide  
  2275-2250 strong, broad N=C=O stretching isocyanate  
  2260-2222 weak CΞN stretching nitrile  
  2260-2190 weak CΞC stretching alkyne disubstituted
  2175-2140 strong S-CΞN stretching thiocyanate  
  2160-2120 strong N=N=N stretching azide  
  2150   C=C=O stretching ketene  
  2145-2120 strong N=C=N stretching carbodiimide  
  2140-2100 weak CΞC stretching alkyne monosubstituted
  2140-1990 strong N=C=S stretching isothiocyanate  
  2000-1900 medium C=C=C stretching allene  
  2000   C=C=N stretching ketenimine  
2000-1650 cm-1          
2000-1650 cm-1 2000-1650 weak C-H bending aromatic compound overtone
           
  1870-1540        
  1818 strong C=O stretching anhydride  
  1750        
  1815-1785 strong C=O stretching acid halide  
  1800-1770 strong C=O stretching conjugated acid halide  
  1775 strong C=O stretching conjugated anhydride  
  1720        
  1770-1780 strong C=O stretching vinyl / phenyl ester  
  1760 strong C=O stretching carboxylic acid monomer
  1750-1735 strong C=O stretching esters 6-membered lactone
  1750-1735 strong C=O stretching δ-lactone γ: 1770
  1745 strong C=O stretching cyclopentanone  
  1740-1720 strong C=O stretching aldehyde  
  1730-1715 strong C=O stretching α,β-unsaturated ester or formates
  1725-1705 strong C=O stretching aliphatic ketone or cyclohexanone or cyclopentenone
  1720-1706 strong C=O stretching carboxylic acid dimer
  1710-1680 strong C=O stretching conjugated acid dimer
  1710-1685 strong C=O stretching conjugated aldehyde  
  1690 strong C=O stretching primary amide free (associated: 1650)
  1690-1640 medium C=N stretching imine / oxime  
  1685-1666 strong C=O stretching conjugated ketone  
  1680 strong C=O stretching secondary amide free (associated: 1640)
  1680 strong C=O stretching tertiary amide free (associated: 1630)
  1650 strong C=O stretching δ-lactam γ: 1750-1700 β: 1760-1730
1670-1600 cm-1          
1670-1600 cm-1 1678-1668 weak C=C stretching alkene disubstituted (trans)
  1675-1665 weak C=C stretching alkene trisubstituted
  1675-1665 weak C=C stretching alkene tetrasubstituted
  1662-1626 medium C=C stretching alkene disubstituted (cis)
  1658-1648 medium C=C stretching alkene vinylidene
  1650-1600 medium C=C stretching conjugated alkene  
  1650-1580 medium N-H bending amine  
  1650-1566 medium C=C stretching cyclic alkene  
  1648-1638 strong C=C stretching alkene monosubstituted
  1620-1610 strong C=C stretching α,β-unsaturated ketone  
1600-1300 cm-1          
1600-1300 cm-1 1550-1500 strong N-O stretching nitro compound  
  1372-1290        
  1465 medium C-H bending alkane methylene group
  1450 medium C-H bending alkane methyl group
  1375        
  1390-1380 medium C-H bending aldehyde  
  1385-1380 medium C-H bending alkane gem dimethyl
  1370-1365        
1400-1000 cm-1          
1400-1000 cm-1 1440-1395 medium O-H bending carboxylic acid  
  1420-1330 medium O-H bending alcohol  
  1415-1380 strong S=O stretching sulfate  
  1200-1185        
  1410-1380 strong S=O stretching sulfonyl chloride  
  1204-1177        
  1400-1000 strong C-F stretching fluoro compound  
  1390-1310 medium O-H bending phenol  
  1372-1335 strong S=O stretching sulfonate  
  1195-1168        
  1370-1335 strong S=O stretching sulfonamide  
  1170-1155        
  1350-1342 strong S=O stretching sulfonic acid anhydrous
  1165-1150       hydrate: 1230-1120
  1350-1300 strong S=O stretching sulfone  
  1160-1120        
  1342-1266 strong C-N stretching aromatic amine  
  1310-1250 strong C-O stretching aromatic ester  
  1275-1200 strong C-O stretching alkyl aryl ether  
  1075-1020        
  1250-1020 medium C-N stretching amine  
  1225-1200 strong C-O stretching vinyl ether  
  1075-1020        
  1210-1163 strong C-O stretching ester  
  1205-1124 strong C-O stretching tertiary alcohol  
  1150-1085 strong C-O stretching aliphatic ether  
  1124-1087 strong C-O stretching secondary alcohol  
  1085-1050 strong C-O stretching primary alcohol  
  1070-1030 strong S=O stretching sulfoxide  
  1050-1040 strong, broad CO-O-CO stretching anhydride  
1000-650 cm-1          
1000-650 cm-1 995-985 strong C=C bending alkene monosubstituted
  915-905        
  980-960 strong C=C bending alkene disubstituted (trans)
  895-885 strong C=C bending alkene vinylidene
  850-550 strong C-Cl stretching halo compound  
  840-790 medium C=C bending alkene trisubstituted
  730-665 strong C=C bending alkene disubstituted (cis)
  690-515 strong C-Br stretching halo compound  
  600-500 strong C-I stretching halo compound  
900-700 cm-1          
900-700 cm-1 880 ± 20 strong C-H bending 1,2,4-trisubstituted  
  810 ± 20        
  880 ± 20 strong C-H bending 1,3-disubstituted  
  780 ± 20        
  (700 ± 20)        
  810 ± 20 strong C-H bending 1,4-disubstituted or  
        1,2,3,4-tetrasubstituted  
  780 ± 20 strong C-H bending 1,2,3-trisubstituted  
  (700 ± 20)        
  755 ± 20 strong C-H bending 1,2-disubstituted  
  750 ± 20 strong C-H bending monosubstituted  
  700 ± 20     benzene derivative  

IR Table by Compound Class

If you already know the frequency range use this IR spectrum chart. If you already know the frequency use the IR frequency table above.

 

Compound Class Group Absorption (cm-1) Appearance Comments
acid halide C=O stretching 1815-1785 strong  
alcohols O-H stretching 3700-3584 medium, sharp free
  O-H stretching 3550-3200 strong, broad intermolecular bonded
  O-H stretching 3200-2700 weak, broad intramolecular bonded
  O-H bending 1420-1330 medium  
aldehyde C-H stretching 2830-2695 medium doublet
  C=O stretching 1740-1720 strong  
  C-H bending 1390-1380 medium  
aliphatic ether C-O stretching 1150-1085 strong  
aliphatic ketone C=O stretching 1725-1705 strong or cyclohexanone or cyclopentenone
aliphatic primary amine N-H stretching 3400-3300 medium  
alkane C-H stretching 3000-2840 medium  
  C-H bending 1465 medium methylene group
  C-H bending 1450 medium methyl group
  C-H bending 1385-1380 medium gem dimethyl
  C-H stretching 3100-3000 medium  
  C=C stretching 1678-1668 weak disubstituted (trans)
  C=C stretching 1675-1665 weak trisubstituted
  C=C stretching 1675-1665 weak tetrasubstituted
  C=C stretching 1662-1626 medium disubstituted (cis)
  C=C stretching 1658-1648 medium vinylidene
  C=C stretching 1648-1638 strong monosubstituted
  C=C bending 995-985 strong monosubstituted
  C=C bending 980-960 strong disubstituted (trans)
  C=C bending 895-885 strong vinylidene
  C=C bending 840-790 medium trisubstituted
  C=C bending 730-665 strong disubstituted (cis)
alkyl aryl ether C-O stretching 1275-1200 strong  
alkyne C-H stretching 3333-3267 strong, sharp  
  CΞC stretching 2260-2190 weak disubstituted
  CΞC stretching 2140-2100 weak monosubstituted
allene C=C=C stretching 2000-1900 medium  
amine N-H bending 1650-1580 medium  
  C-N stretching 1250-1020 medium  
amine salt N-H stretching 3000-2800 strong, broad  
anhydride C=O stretching 1818 strong  
  CO-O-CO stretching 1050-1040 strong, broad  
aromatic amine C-N stretching 1342-1266 strong  
aromatic compound C-H bending 2000-1650 weak overtone
aromatic ester C-O stretching 1310-1250 strong  
azide N=N=N stretching 2160-2120 strong  
benzene derivative   700 ± 20    
carbodiimide N=C=N stretching 2145-2120 strong  
carbon dioxide O=C=O stretching 2349 strong  
carboxylic acid O-H stretching 3300-2500 strong, broad usually centered on 3000 cm-1
  C=O stretching 1760 strong monomer
  C=O stretching 1720-1706 strong dimer
  O-H bending 1440-1395 medium  
conjugated acid C=O stretching 1710-1680 strong dimer
conjugated acid halide C=O stretching 1800-1770 strong  
conjugated aldehyde C=O stretching 1710-1685 strong  
conjugated alkene C=C stretching 1650-1600 medium  
conjugated anhydride C=O stretching 1775 strong  
conjugated ketone C=O stretching 1685-1666 strong  
cyclic alkene C=C stretching 1650-1566 medium  
cyclopentanone C=O stretching 1745 strong  
ester C-O stretching 1210-1163 strong  
esters C=O stretching 1750-1735 strong 6-membered lactone
fluoro compound C-F stretching 1400-1000 strong  
halo compound C-Cl stretching 850-550 strong  
  C-Br stretching 690-515 strong  
  C-I stretching 600-500 strong  
imine / oxime C=N stretching 1690-1640 medium  
isocyanate N=C=O stretching 2275-2250 strong, broad  
isothiocyanate N=C=S stretching 2140-1990 strong  
ketene C=C=O stretching 2150    
ketenimine C=C=N stretching 2000    
monosubstituted C-H bending 750 ± 20 strong  
nitrile CΞN stretching 2260-2222 weak  
nitro compound N-O stretching 1550-1500 strong  
none   3330-3250    
none   1870-1540    
none   1750    
none   1720    
none   1372-1290    
none   1375    
none   1370-1365    
none   1200-1185    
none   1204-1177    
none   1195-1168    
none   1170-1155    
none   1165-1150   hydrate: 1230-1120
none   1160-1120    
none   1075-1020    
none   1075-1020    
none   915-905    
none   810 ± 20    
none   780 ± 20    
none   (700 ± 20)    
none   (700 ± 20)    
phenol O-H bending 1390-1310 medium  
primary alcohol C-O stretching 1085-1050 strong  
primary amide C=O stretching 1690 strong free (associated: 1650)
  N-H stretching 3500 medium  
secondary alcohol C-O stretching 1124-1087 strong  
secondary amide C=O stretching 1680 strong free (associated: 1640)
secondary amine N-H stretching 3350-3310 medium  
sulfate S=O stretching 1415-1380 strong  
sulfonamide S=O stretching 1370-1335 strong  
sulfonate S=O stretching 1372-1335 strong  
sulfone S=O stretching 1350-1300 strong  
sulfonic acid S=O stretching 1350-1342 strong anhydrous
sulfonyl chloride S=O stretching 1410-1380 strong  
sulfoxide S=O stretching 1070-1030 strong  
tertiary alcohol C-O stretching 1205-1124 strong  
tertiary amide C=O stretching 1680 strong free (associated: 1630)
thiocyanate S-CΞN stretching 2175-2140 strong  
thiol S-H stretching 2600-2550 weak  
vinyl / phenyl ester C=O stretching 1770-1780 strong  
vinyl ether C-O stretching 1225-1200 strong  
α,β-unsaturated ester C=O stretching 1730-1715 strong or formates
α,β-unsaturated ketone C=C stretching 1620-1610 strong  
δ-lactam C=O stretching 1650 strong γ: 1750-1700 β: 1760-1730
δ-lactone C=O stretching 1750-1735 strong γ: 1770
1,2,3,4-tetrasubstituted        
1,2,3-trisubstituted C-H bending 780 ± 20 strong  
  C-H bending 880 ± 20 strong  
1,2-disubstituted C-H bending 755 ± 20 strong  
  C-H bending 880 ± 20 strong  
1,4-disubstituted or C-H bending 810 ± 20 strong  

How to Read an IR Spectrum Table

To use an IR spectrum table, first find the frequency or compound in the first column, depending on which type of chart you are using. Then find the corresponding values for absorption, appearance and other attributes. The value for absorption is usually in cm-1.

Note that not all frequencies have a related compound. 

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