Alkynes vs. Nitriles
Both will have peaks for the triple bond, but the peak for a nitrile will be much more intense. For alkynes, as with alkenes, the peak for an internal triple bond may be small and hard to find. The more symetrically substituted the alkyne, the smaller the peak. For a terminal alkyne, not only is the triple bond peak easy to spot, but there will also be a peak for the sp C-H bond.
The examples used for this exercise are phenylacetylene and phenylacetonitrile. See if you can figure out which 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. | |