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
NO2 stretch 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