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IR Frequencies
Infrared spectroscopy frequencies
| Question | cm -1 |
|---|---|
| Alkane sp3 C-H stretch | 2950 |
| Alkene sp2 C-H stretch | 3050 |
| C=C stretch | 1600 (often weak) |
| Alkynes sp C-H stretch | 3300 |
| C-tb-C stretch | 2200 |
| Alcohols O-H stretch | 3440 (usually big and broad) |
| C-O stretch | 1150 |
| Ketones C=O stretch | 1710 |
| Aldehydes C=O stretch | 1710 |
| Aldehydes C-H stretch | 2800 |
| Esters C=O stretch | 1735 |
| Esters C-O stretch | 1150 |
| Carboxylic acids C=O stretch | 1710 |
| Carboxylic acids O-H stretch | 3400 to 2800 (usually VERY big and broad) |
| N-H stretch | 3400 |
| 1* amine (-NH2) | two peaks |
| 2* amine | one peak |
| 3* amine | no peak |
| C-N stretch | about like C-O stretch |
| Amides C=O | 1810 |
| Acid Anhydrides two C=O stretches | 1820, 1760 |
| Benzene Rings C-C ring bonds | 1450 |
| Aromatic C-H out-of-plane bonding | 750 |
| C-tb-N stretch | 2200 |