IR spectra functional groups

BLUE PEAK

carbonyl. 1600-1800, strong peak. found in ketones and aldehydes

first big peak

OH group (alcohol) found around 3100-3500, strong broad peak. will be sharper if there is also a carbonyl

first little peak with two bumps

PRIMARY amine. primarys will always have 2 little peaks. smaller, around 3100-3500

first peak of the spectra

SECONDARY amine, will have only one peak 3100-3500 region, small/medium peak not super sharp or broad

smooth portion

TERTIARY amine, will have no real peak. looks like a weird little hill 3100-3500 region.

blacked out peaks

alkynes, super skinny pointy peaks around 2100-2300. can also be at 3300, these ones will usually be sharper

highlighted “a” peak

nitrile, 2100-2300. stronger and sharper than a regular alkyne looks reallly similar

look at all peaks. this functional group has 2 important ones that must be present!

carboxylic acid, found around 3100-3500. carbonyl and much weaker OH peak than alcohol (not as broad) with bumps on the bottom.

look for important section. what’s missing and what does this tell us?

ketone. Carbonyl around 1700, NO OH GROUP. anything above like 2500 should be pretty empty no big peaks

look at the whole spectra, whats here and whats missing

aldehyde. will have a strong carbonyl peak around 1700, shouldnt have any OH