N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
351
7.11 Carbonyl Compounds
351
Assignment
Range
Comments
≈1650
Enol form
≈1615
Enol with intramolecular H bonds,
C=C st: ≈1600, strong
γ-Diketones:
As monoketones
≈1675
p-Quinones; with peri-OH: ≈1675, ≈1630
C=C st: ≈1600
C=C=O st as
2155–2130
Very strong
Examples (v ~ in cm -1 )
O
1691
O
1697
O
O
s-trans 1690
s-cis 1707
s-trans
s-cis
O
1672
1660
O
1678
(2222)
O
1692
O
1701
O
O 2 N
1702
O
H 2 N
1676
O
1664
O
N
N
1639
OH O
1648
Cl
O
1752
1726
(rotamers)
Cl 3 C
O
CCl 3
1780
1751
O
Cl
1722
H 9 C 4
C 4 H 9
O
O
1710
O
O
1700
1655
O
O
1735
O
O
1724 (keto form)
1608 (enol form)
O
O
1755
1725
1635
1590
O
O
1630
1607