Identifying Functional Groups in Organic Chemistry
IR spectroscopy is a useful tool for identifying organic molecules. However, it is limited.
Its main application is identifying the functional groups in molecules. Below is a scheme that contains the most common IR values you will see in your OChem class:
Here is the simple key:
Green = Peak Shape; Blue = C-H peak values; Orange = All other peaks
How to use your IR spectra to solve problems
Typically, IR spectroscopy is used together with 1H NMR to solve unknown structures.
If you have an IR and an H-NMR spectra on an exam, start by looking at the IR spectra. This way you can identify your possible functional groups. Then move on to the H-NMR spectra.
Need help with H-NMR?
Don’t forget to check out Guide to Solving NMR Questions!