IR table

last updated: Friday, March 9, 2001

Infrared Spectroscopy Table

Functional Group Frequency (cm-1) intensity

water OH Stretch 3700-3100 strong

alcohol OH stretch 3600-3200 strong

carboxylic acid OH stretch 3600-2500 strong

N-H stretch 3500-3350 strong

stretch ~3300 strong

=C-H stretch 3100-3000 weak

-C-H stretch 2950-2840 weak

-C-H aldehydic 2900-2800 variable

stretch ~2250 strong

stretch 2260-2100 variable

C=O aldehyde 1740-1720 strong

C=O anhydride 1840-1800, 1780-1740 weak, strong

C=O ester 1750-1720 strong

C=O ketone 1745-1715 strong

C=O amide 1700-1500 strong

C=C alkene 1680-1600 weak

C=C aromatic 1600-1400 weak

CH₂ bend 1480-1440 medium

CH₃ bend 1465-1440, 1390-1365 medium

C-O-C stretch 1250-1050 several strong

C-OH stretch 1200-1020 strong

NO₂stretch 1600-1500 and 1400-1300 strong

C-F 1400-1000 strong

C-Cl 800-600 strong

C-Br 750-500 strong

C-I ~500 strong

Functional Group	Frequency (cm-1)	intensity
water OH Stretch	3700-3100	strong
alcohol OH stretch	3600-3200	strong
carboxylic acid OH stretch	3600-2500	strong
N-H stretch	3500-3350	strong
stretch	~3300	strong
=C-H stretch	3100-3000	weak
-C-H stretch	2950-2840	weak
-C-H aldehydic	2900-2800	variable
stretch	~2250	strong
stretch	2260-2100	variable
C=O aldehyde	1740-1720	strong
C=O anhydride	1840-1800, 1780-1740	weak, strong
C=O ester	1750-1720	strong
C=O ketone	1745-1715	strong
C=O amide	1700-1500	strong
C=C alkene	1680-1600	weak
C=C aromatic	1600-1400	weak
CH₂ bend	1480-1440	medium
CH₃ bend	1465-1440, 1390-1365	medium
C-O-C stretch	1250-1050 several	strong
C-OH stretch	1200-1020	strong
NO₂stretch	1600-1500 and 1400-1300	strong
C-F	1400-1000	strong
C-Cl	800-600	strong
C-Br	750-500	strong
C-I	~500	strong