Orgo IR wavenumbers and functional groups

C≡N stretching

2260-2220cm^-1

aldehylic/formaldehyde C=O stretch

1700 cm-1

aldehyde C-H stretch

2710 cm-1

C≡C stretching

2260-2100cm-1

C=N stretching

1650-1550 cm^-1

C=C stretching

1680-1600cm -1

aromatic ring

1600 and 1500-1430 cm^{-1 (span of peaks between 1600-2200)}

C-H bending (fingerprint region)

1000-600 cm^-1

C-H stretching

2850-2960cm^-1

C-F stretching

1000-1100cm^-1

-CF3

1300-1360cm^-1

=C-H bend

875-990 cm^-1

terminal alkene stretching

3000-3100 cm^-1 moderate

-CH=CH2 **bending

910, 990 cm^-1 sharp, two absorptions 890 cm^-1 sharp

trans alkene bending (hydrogens on opposite sides)

960-980cm^-1 sharp

cis alkene bending (hydrogens on same side)

675-730cm^-1 broad (variable for different compounds)

trisubstituted alkene bending

800-840 cm^-1

O-H stretch (alcohol)

3650-3200cm^{-1 BROAD}

O-H stretch (carboxylic acid)

3300-2500cm^-1

C-O stretch (ROH and ethers)

1250-1050 cm^{-1 strong}

C≡C stretching

2260-2100cm^-1

≡C-H stretching

3300 cm-1

=C-H stretching

3100 cm-1

N-H stretching primary amine

2 peaks, 3200-3375cm-1

N-H stretching, secondary amines

1 peak, 3200-3375

C-N

1230-1020cm-1

C=O stretching

1780-1650cm-1 strong