more energy and is at slightly higher frequency.

•  The O–H bands occur at higher frequency, sometimes as a sharp absorption at about 3600 cm^-1 . More often, you will see a broad absorption at anywhere from 3500 to 2900 cm^-1. This is because OH groups form strong hydrogen bonds that vary in length and strength. The sharp absorption at 3600 cm^-1 is the non-hydrogen-bonded OH and the lower the absorption the stronger the H bond.