N
X
C
O
N
S
Hal
Solvents
Natural
Products
P Si
C
C
C C
C
C
318
7 IR
Assignment
Range
Comments
ar C–H δ oop 900–650
One or more strong bands; useful for determining substitution patterns in 6-membered
aromatic rings. In Raman, generally weak
In the same range: =C–H δ oop, C–O–C γ and C–N–C γ in
saturated heterocyclics, OH δ oop in
carboxylic acids, NH δ, N–O st, S–O st, CH 2
γ, C–F δ, C–Cl st
Determination of Substitution Patterns in 6-Membered Aromatic Rings: Position
and Shape of Bands Related to the Number of Adjacent H Atoms (v ~ in cm -1 )
Not reliable for ring systems with strongly conjugated substituents such as C=O,
NO 2 , C– – – N.
Comb, overtones Substitution type;
CH δ oop, ar C–C γ
Comb, overtones Substitution type;
CH δ oop, ar C–C γ
2000
1600
mono≈900
770–730
710–690
2000
1600
o-di770–735
2000
1600
m-di900–860
865–810
810–750
725–680
2000
1600
vic-tri800–770
780–760
720–685
2000
1600
1,2,4-tri900–860
860–800
730–690
2000
1600
p-di860–780
2000
1600
1,2,3,4-tetra860–780
2000
1600
1,3,5-tri900–840
850–800
730–675