Summary Pearson (Edexcel) A-Level Chemistry Chemical Reference Data Infrared Spectroscopy Frequencies Table Overview

Bond Absorption frequency\range (cm^-1) Type of vibration Intensity
O—H (“free”) 3850-3670 Strong
O—H (alcohol, hydrogen-bonded) 3750-3200 Stretching Variable (broad)
O—H (alcohol, not hydrogen-bonded) 3650-3590 Stretching Variable (sharp)
N—H (amine) 3500-3300 Stretching Medium
N—H (amide) 3500-3140 Stretching Medium
C—H (alkyne) 3300 Stretching Strong
O—H (carboxylic acid) 3300-2500 Stretching Weak
C—H (alkene) 3095-3010 Stretching Medium
C—H (arene) 3030 Stretching Variable
C—H (alkane) 2962-2853 Stretching Medium~strong
2900-2820 Stretching Weak
C—H (aldehyde) 2775-2700 Stretching Weak
C≡N 2260-2215 Stretching Medium
C≡C 2260-2100 Stretching Medium, variable
C＝O (carboxylic acid anhydride, saturated) 1850-1800 Stretching Strong
C＝O (acyl bromide) 1810 Stretching Strong
C＝O (ester, alkenyl) 1800-1770 Stretching Strong
C＝O (acyl chloride) 1795 Stretching Strong
C＝O (carboxylic acid anhydride, saturated) 1790-1740 Stretching Strong
C＝O (ester, saturated) 1750-1735 Stretching Strong
C＝O (aldehyde, alkyl - saturated) 1740-1720 Stretching Strong
C＝O (ester, aryl) 1730-1717
C＝O (carboxylic acid, alkyl - saturated) 1725-1700 Stretching Strong
C＝O (carboxylic acid, aryl) 1700-1680 Stretching Strong
C＝O (ketone, alkyl/aryl) 1700-1680 Stretching Strong
C＝O (amide) 1700-1630 Stretching Strong
C＝C (alkene, isolated) 1669-1645 Stretching Variable
1600 Stretching Variable
1580 Stretching Medium
C＝C (arene)