One of the following functional groups, sometimes shows a single weak to medium IR adsorption peak in the 2100 to 2250 cm^-1 range. Depending on the structure of the compound this peak is sometimes not present, making it easy to misinterpret the spectrum. Which functional group is it?

Question

Quizplus · Accepted Answer

The alkyne functional group shows a C≡C stretching vibration in the IR spectrum, which appears as a weak to medium absorption peak in the 2100 to 2250 cm-1 range. However, this peak may not be present in certain compounds, especially if the alkyne is conjugated with another functional group or if it is a terminal alkyne with a hydrogen attached to the carbon. Therefore, the presence of this peak should always be confirmed with other spectroscopic techniques.

One of the Following Functional Groups, Sometimes Shows a Single