- “Stretching”:
Symmetric stretching Asymmetric stretching
- “Bending”:
Symmetric bending Asymmetric bending
- H 2 O: 3 fundamental vibrational modes 3N – 3 – 3 = 3
Symmetrical stretching Asymmetrical stretching Scissoring
(νs OH) (νas OH) (νs HOH)
3652 cm–1 (2.74 μm) 3756 cm–1 (2.66 μm) 1596 cm–1 (6.27 μm)
coupled stretching
- CO 2 : 4 fundamental vibrational modes 3N – 3 – 2 = 4
Symmetrical stretching Asymmetrical stretching
(νs CO) (νas CO)
1340 cm–1 (7.46 μm) 2350 cm–1 (4.26 μm)
coupled stretching normal C=O 1715 cm–1