The mid-infrared spectrum (4000–400

The mid-infrared spectrum (4000–400 cm-1) can be approximately divided
into four regions and the nature of a group frequency may generally be
determined by the region in which it is located. The regions are generalized
as follows: the X–H stretching region (4000–2500 cm-1), the triple-bond
region (2500–2000 cm-1), the double-bond region (2000–1500 cm-1) and the
fingerprint region (1500–600 cm-1).