| |
|
Bond Type |
Specific Context |
n,
cm-1 |
|
Stretching Frequencies |
|
|
|
C-H |
Csp3-H |
2800-3000 |
|
|
Csp2-H |
3000-3100 |
|
|
Csp-H |
3300 |
|
C-C |
C-C |
1150-1250 |
|
|
C=C |
1600-1670 |
|
|
CºC |
2100-2260 |
|
C-N |
C-N |
1030-1230 |
|
|
C=N |
1640-1690 |
|
|
CºN |
2210-2260 |
|
C-O |
C-O |
1020-1275 |
|
nC-O~1630(o)/1650(do)
(H-bond) |
C=O |
1650-1800 (1690 no H-bond) |
|
C-X |
C-F |
1000-1350 |
|
|
C-Cl |
800-850 |
|
|
C-Br |
500-680 |
|
|
C-I |
200-500 |
|
N-H |
RNH2, R2NH |
3400-3500 (two) |
|
nN-H
~ 3450 (non H-bond) |
RNH3+, R2NH2+,
R3NH+ |
2250-3000 |
|
nN-H~3340/3320
s-o, b-do (H-bnd) |
RCONH2, RCONHR' |
3400-3500 |
|
O-H |
ROH |
3610-3640 (free) |
|
|
|
3200-3400 (H-bonded) |
|
|
RCO2H |
2500-3000 |
|
N-O |
RNO2 |
1350,1560 |
|
|
RONO2 |
1620-1640, 1270-1285 |
|
|
RN=O |
1500-1600 |
|
|
RO-N=O |
1610-1680 (two), 750-815 |
|
|
C=N-OH |
930-960 |
|
|
R3N-O+ |
950-970 |
|
S-O |
R2SO |
1040-1060 |
|
|
R2S(=O)O |
1310-1350
1120-1160 |
|
|
R-S(=O)2-OR' |
1330-1420, 1145-1200 |
|
Cumulated Systems |
C=C=C |
1950 |
|
|
C=C=O |
2150 |
|
|
R2C=N=N |
2090-3100 |
|
|
RN=C=O |
2250-2275 |
|
|
RN=N=N |
2120-2160 |
|
Out-of-Plane Bending Vibrations |
|
|
|
Alkynes |
CºC-H |
600-700 |
|
Alkenes |
RCH=CH2 |
910, 990 |
|
|
R2C=CH2 |
890 |
|
|
trans-RCH=CHR |
970 |
|
|
cis-RCH=CHR |
725, 675 |
|
|
R2C=CHR |
790-840 |
|
Aromatic |
mono- |
730-770, 690-710 (two) |
|
|
o- |
735-770 |
|
|
m- |
750-810, 690-710 (two) |
|
|
p- |
810-840 |
|
|
1,2,3- |
760-780, 705-745 (two) |
|
|
1,3,5- |
810-865, 675-730 (two) |
|
|
1,2,4- |
805-825, 870, 885 (two) |
|
|
1,2,3,4- |
800-810 |
|
|
1,2,4,5- |
855-870 |
|
|
1,2,3,5 |
840-850 |
|
|
penta- |
870 |
|
Carbonyl Stretching Frequencies |
|
|
|
Aldehydes |
RCHO |
1725 |
|
|
C=CCHO |
1685 |
|
|
ArCHO |
1700 |
|
Ketones |
R2C=O |
1715 |
|
|
C=C-C=O |
1675 |
|
|
Ar-C=O |
1690 |
|
|
four-membered cyclic |
1780 |
|
|
five-membered cyclic |
1745 |
|
|
six-membered cyclic |
1715 |
|
Carboxylic Acids |
RCOOH |
1760 (monomer)
1710 (dimer) |
|
|
C=C-COOH |
1720 (monomer)
1690 (dimer) |
|
|
RCO2- |
1550-1610, 1400 (two) |
|
Esters |
RCOOR |
1735 |
|
|
C=C-COOR |
1720 |
|
|
ArCOOR |
720 |
|
|
g-lactone |
1770 |
|
|
d-lactone |
1735 |
|
Amides |
RCONH2 |
1690 (free)
1650 (associated) |
|
|
RCONHR' |
1680 (free)
1655 (associated) |
|
|
RCONR2' |
1650 |
|
|
HCONR2 |
1670 |
|
|
b-lactam |
1745 |
|
|
g-lactam |
1700 |
|
|
d-lactam |
1640 |
|
Acid anhydrides |
|
1820, 1760 (two) |
|
Acyl halides |
|
1800 |
|
|
