How can you memorize the IR spectra?

Jul 4, 2016

The simple answer is you don't.

Explanation:

IR spectroscopy identifies a few bonds unambiguously. If your compound has a $C = O$ or $C \equiv O$, or $N \equiv O$, functionality, the the IR spectrum will identify these. But most of the time you know they are there already. See this older answer. and also here.