| Group | Frequency Range (cm-1) |
| OH stretching vibrations | |
| Free OH | 3610-3645 (sharp) |
| Intramolecular H bonds | 3450-3600 (sharp) |
| Intermolecular H Bonds | 3200-3550 (broad) |
| Chelate Compounds | 2500-3200 (very broad) |
| NH Stretching vibrations | |
| Free NH | 3300-3500 |
| H bonded NH | 3070-3350 |
| CH Stretching vibrations | |
| =-C-H | 3280-3340 |
| =C-H | 3000-3100 |
| C-CH3 | 2862-2882, 2652-2972 |
| O-CH3 | 2815-2832 |
| N-CH3 (aromatic) | 2810-2820 |
| N-CH3 (aliphatic) | 2780-2805 |
| CH2 | 2843-2863,2916-2936 |
| CH | 2880-2900 |
| SH Stretching Vibrations | |
| Free SH | 2550-2600 |
| C=-N Stretching Vibrations | |
| Nonconjugated | 2240-2260 |
| Conjugated | 2215-2240 |
| C=-C Stretching Vibrations | |
| C=-CH (terminal) | 2100-2140 |
| C-C=-C-C | 2190-2260 |
| C-C=-C-C=-CH | 2040-2200 |
| C=O Stretching Vibrations | |
| Nonconjugated | 1700-1900 |
| Conjugated | 1590-1750 |
| Amides | ~1650 |
| C=C Sretching Vibrations | |
| Nonconjugated | 1620-1680 |
| Conjugated | 1585-1625 |
| CH Bending Vibrations | |
| CH2 | 1405-1465 |
| CH3 | 1355-1395, 1430-1470 |
| C-O-C Vibrations in Esters | |
| Formates | ~1175 |
| Acetates | ~1240, 1010-1040 |
| Benzoates | ~1275 |
| C-OH Stretching Vibrations | |
| Secondary Cyclic Alcohols | 990-1060 |
|
CH out-of-plane bending vibrations
in substituted ethylenic systems |
|
| -CH=CH2 | 905-915, 985-995 |
| -CH=CH-(cis) | 650-750 |
| -CH=CH-(trans) | 960-970 |
| C=CH2 | 885-895 |