Arenes
In addition to the stretching vibrations at 3000 70 cm
-1
, several sharp, weaker
absorptions in the 950 to 1250 range due to in-plane C-H bending vibrations also
occur.. These are not diagnostically useful, except for indicating a substituted benzene
ring. Weak overtone and combination tone absorptions are found in the 1600-2000
region
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