N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
341
7.9 Nitrogen Compounds
341
Typical Ranges (v ~ in cm -1 )
Assignment
Range
Comments
SC– – – N st
2170–2130
2090–2020
Medium, sharp
(SC – – – N) –
C–S st
750-550
Often doublet
N=C=S st as
2200–2050
Very strong, generally doublet, Fermi resonance
N=C=S st sy
950–650
≈950
700–650
aliphatic –N=C=S
aromatic –N=C=S
Beyond normal range:
2090–2020
(N=C=S) –
C–N st
1090–1075
Examples (v ~ in cm -1 )
CH 3 –SCN
2157
SCN
2158
SCN
2170
CH 3 –NCS
neat:
2206
2114
in CCl 4 :
2221
2106
2077
N CS
2173
2097
2068
NCS
2105
N CS
2062
NCS
neat: 2090
in CCl 4 : 2065
in CHCl 3 : 2112