Ketones vs. Esters
This one can be pretty tough. The frequency of the carbonyl peak of an ester is normally higher than that for a ketone. Esters will also have peaks for the C-O bonds in the fingerprint region, and they are usually big enough that they are easy to pick out if you know to look for them. It also helps to have other information to go on, like the molecular formula.
The compounds used in this exercise are acetophenone and methyl benzoate. See if you can figure out which one is which.
Compound A
| Expand any region: | ||||||
| 4000 - 3200 cm-1 | 3200 - 2700 cm-1 | 2700 - 2000 cm-1 | 2000 - 1660 cm-1 | 1660 - 1400 cm-1 | 1400 - 900 cm-1 | 900 - 600 cm-1 |
| Get the molecular formula of this compound. | Get the name of this compound. | Get the structure of this compound. | Go to the IR data tables. | Get an unknown. | Go back to the IR exercise homepage. | |
Compound B
| Expand any region: | ||||||
| 4000 - 3200 cm-1 | 3200 - 2700 cm-1 | 2700 - 2000 cm-1 | 2000 - 1660 cm-1 | 1660 - 1400 cm-1 | 1400 - 900 cm-1 | 900 - 600 cm-1 |
| Get the molecular formula of this compound. | Get the name of this compound. | Get the structure of this compound. | Go to the IR data tables. | Get an unknown. | Go back to the IR exercise homepage. | |