N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
333
7.9 Nitrogen Compounds
333
Typical Ranges (v ~ in cm -1 )
Assignment
Range
Comments
NO 2 st as
1660–1490
Very strong, of medium width. In Raman, of
weak to medium intensity
Subranges:
1660–1625
1570–1540
1560–1490
1630–1530
O–NO 2 , nitrates; missing in Raman
C–NO 2 , aliphatic nitro compounds
C–NO 2 , aromatic nitro compounds
N–NO 2 , nitramines
NO 2 st sy
1390–1260
Strong, of medium width
Subranges:
1285–1270
1390–1340
1360–1310
1315–1260
O–NO 2 , nitrates
C–NO 2 , aliphatic nitro compounds
C–NO 2 , aromatic nitro compounds;
often 2 bands
N–NO 2 , nitramines
In nitrates also:
≈870
≈760
≈700
N–O st, strong
NO 2 γ
NO 2 δ
Ring δ
760–705
Strong; modified deformation of aromatic ring
N=O st
1680–1450
1420–1250
Very strong, in monomers
Very strong, in dimers
Subranges:
1680–1650
1585–1540
1510–1490
≈1450
O–NO (nitrites) trans; 1625–1610: cis
C–NO, aliphatic C-nitroso compounds
C–NO, aromatic C-nitroso compounds
N–NO, N-nitroso compounds
In nitrites also:
3300–3200,
≈2500,
2300–2250
comb
≈800
N–O st trans; cis: very weak
≈600
O–NO δ trans; cis: ≈650
C–N st
≈850
C–NO, aliphatic C-nitroso compounds; coupled
with other vibrations
≈1100
C–NO, aromatic C-nitroso compounds
N–N st
≈1040
N-Nitroso compounds