Atoms mode type Region (cm-1)
O-H stretch free 3600-3650
    H-bonded 3200-3500
N-H stretch sym 3100-3500
    asym  
C-H stretch alkynes 3300
    aromatics 3050-3150
    alkenes 3000-3100
    alkanes 2850-3000
    aldehydes 2700-2900
C=N   nitriles 2240-2260
C=C   alkynes 2100-2250
X=C=Y   allenes 1950-2270
C=O   anhydride 1760 & 1810
    acid chloride 1800
    ester 1730-1750
    aldehyde 1720-1740
    ketone 1705-1725
    carboxylic acid 1700-1725
    amide 1640-1670
C=N   imine 1640-1690
C=C   alkene 1600-1680
    aromatic 1475 & 1600
O-H      
N-H bend   1550-1640
C-H bend -CH2- 1465
    -CH3 1375 & 1450
C-N   amines 1000-1350
C-O   alcohols 1000-1300
C-H out-of-plane bend alkenes 650-1000
    aromatics 690-900