Infrared spectroscopy correlation table


An infrared spectroscopy correlation table is a list of absorption peaks and frequencies, typically reported in wavenumber, for common types of molecular bonds and functional groups. In physical and analytical chemistry, infrared spectroscopy is a technique used to identify chemical compounds based on the way infrared radiation is absorbed by the compound.
The absorptions in this range do not apply only to bonds in organic molecules. IR spectroscopy is useful when it comes to analysis of inorganic compounds as well.

Group frequencies

Tables of vibrational transitions of stable and transient molecules are also available.
BondType of bondSpecific type of bondAbsorption peak Appearance
C─Halkylmethyl1260strong
C─Halkylmethyl1380weak
C─Halkylmethyl2870medium to strong
C─Halkylmethyl2960medium to strong
C─Halkylmethylene1470strong
C─Halkylmethylene2850medium to strong
C─Halkylmethylene2925medium to strong
C─Halkylmethine2890weak
C─HvinylC═CH2900strong
C─HvinylC═CH22975medium
C─HvinylC═CH23080medium
C─HvinylC═CH3020medium
C─Hvinylmonosubstituted alkenes900strong
C─Hvinylmonosubstituted alkenes990strong
C─Hvinylcis-disubstituted alkenes670–700strong
C─Hvinyltrans-disubstituted alkenes965strong
C─Hvinyltrisubstituted alkenes800–840strong to medium
C─Haromaticbenzene/sub. benzene3070weak
C─Haromaticmonosubstituted benzene700–750strong
C─Haromaticmonosubstituted benzene690–710strong
C─Haromaticortho-disub. benzene750strong
C─Haromaticmeta-disub. benzene750–800strong
C─Haromaticmeta-disub. benzene860–900strong
C─Haromaticpara-disub. benzene800–860strong
C─Halkynesany3300medium
C─Haldehydesany2720medium
C─Haldehydesany2820medium
C═Cacyclic C═Cmonosub. alkenes1645medium
C═Cacyclic C═C1,1-disub. alkenes1655medium
C═Cacyclic C═Ccis-1,2-disub. alkenes1660medium
C═Cacyclic C═Ctrans-1,2-disub. alkenes1675medium
C═Cacyclic C═Ctrisub., tetrasub. alkenes1670weak
C═Cconjugated C═Cdienes1600strong
C═Cconjugated C═Cdienes1650strong
C═Cwith benzene ringdienes1625strong
C═Cwith C═Odienes1600strong
C═CC═C any1640–1680medium
C═Caromatic C═Cany1450weak to strong
C═Caromatic C═Cany1500weak to strong
C═Caromatic C═Cany1580weak to strong
C═Caromatic C═Cany1600weak to strong
C═CC≡Cterminal alkynes2100–2140weak
C═CC≡Cdisubst. alkynes2190–2260very weak
C=Oaldehyde/ketonesaturated aliph./cyclic 6-membered1720
C=Oaldehyde/ketoneα,β-unsaturated1685
C=Oaldehyde/ketonearomatic ketones1685
C=Oaldehyde/ketonecyclic 5-membered1750
C=Oaldehyde/ketonecyclic 4-membered1775
C=Oaldehyde/ketonealdehydes1725influenced by conjugation
C=Ocarboxylic acids/derivatessaturated carboxylic acids1710
C=Ocarboxylic acids/derivatesunsat./aromatic carb. acids1680–1690
C=Ocarboxylic acids/derivatesesters and lactones1735influenced by conjugation and ring size
C=Ocarboxylic acids/derivatesanhydrides1760
C=Ocarboxylic acids/derivatesanhydrides1820
C=Ocarboxylic acids/derivatesacyl halides1800
C=Ocarboxylic acids/derivatesamides1650associated amides
C=Ocarboxylic acids/derivatescarboxylates 1550–1610
C=Ocarboxylic acids/derivatesamino acid zwitterions1550–1610
O─Halcohols, phenolslow concentration3610–3670
O─Halcohols, phenolshigh concentration3200–3400broad
O─Hcarboxylic acidslow concentration3500–3560
O─Hcarboxylic acidshigh concentration3000broad
N─Hprimary aminesany3400–3500strong
N─Hprimary aminesany1560–1640strong
N─Hsecondary aminesany>3000weak to medium
N─Hammonium ionsany2400–3200multiple broad peaks
C─Oalcoholsprimary1040–1060strong, broad
C─Oalcoholssecondary~1100strong
C─Oalcoholstertiary1150–1200medium
C─Ophenolsany1200
C─Oethersaliphatic1120
C─Oethersaromatic1220–1260
C─Ocarboxylic acidsany1250–1300
C─Oestersany1100–1300two bands
C─Naliphatic aminesany1020–1220often overlapped
C─NC═Nany1615–1700similar conjugation effects to C═O
C─NC≡N unconjugated2250medium
C─NC≡N conjugated2230medium
C─NR─N─C any2165–2110
C─NR─N═C═Sany2140–1990
C─Xfluoroalkanesordinary1000–1100
C─Xfluoroalkanestrifluromethyl1100–1200two strong, broad bands
C─Xchloroalkanesany540–760weak to medium
C─Xbromoalkanesany500–600medium to strong
C─Xiodoalkanesany500medium to strong
N─Onitro compoundsaliphatic1540stronger
N─Onitro compoundsaliphatic1380weaker
N─Onitro compoundsaromatic1520lower if conjugated
N─Onitro compoundsaromatic1350lower if conjugated
P─COrganophosphorus compoundaromatic1440-1460medium
P─Ophosphorus oxidebonded1195-1250strong
P─Ophosphorus oxidefree1250-1300strong