N
X
C
O
N
S
Hal
Solvents
Natural
Products
P Si
C
C
C C
C
C
362
7 IR
7.11.8 Carbonic Acid Derivatives
Carbonic Acid Esters
Carbamates
Ureas
Typical Ranges (v ~ in cm -1 )
Assignment
Range
Comments
C=O st
1820–1740 Strong. In Raman, weak to medium Carbonic
acid esters
1750–1680 Strong. In Raman, weak to medium Carbamates
1690–1620 Strong. In Raman, weak to medium Ureas
C–O st as
1260–1150 Strong
Carbonic
acid esters
%T
400
800
1200
1600
2000
2800
3600
C=O st
C–O st as
%T
400
800
1200
1600
2000
2800
3600
C=O st
N–CO–O st as
N–H st
N–H δ
N–CO–O st sy
%T
400
800
1200
1600
2000
2800
3600
C=O st
C–N–H δ
N–H st
NH 2 δ