Common Functional Group Ir Spectroscopy Absorbances

Front 1

Zone 1

Back 1

3700-3200 cm^-1
Alcohol: O-H
Amide/Amine: N-H
Terminal Alkyne: ≡ C-H

Front 2

Zone 2

Back 2

3200-2700 cm^-1
Alkyl C-H (peak < 3000 cm^-1)
Aryl or vinyl C-H (peak > 3000 cm^-1)
Aldehyde C-H
Carboxylic Acid O-H

Front 3

Zone 3

Back 3

2300-2000 cm^-1
Alkyne C ≡ C
Nitrile C ≡ N

Front 4

Zone 4

Back 4

1850 – 1650 cm^-1
Carbonyl functional groups

Front 5

Zone 5

Back 5

1680-1450 cm^-1
Alkene C=C
Benzene

Front 6

Mnemonic for remembering?

Back 6

Memorizing
 stretching 
frequency
 can 
be 
fun,
let’s 
start
with
 zone 
one.
A 
mean 
(Amine)
 Amide 
met 
a
 fine
 Alkyne
 drinking
Alcohol
A
 real
 (Aryl) 
vinyl
 gets 
all 
the 
hide
(Aldehyde) 
while 
the
rest
 of 
us
 all 
kill 
(alkyl )
to 
be 
cool 
(Cooh,

Carboxylic
 Acid)‐
that’s 
the 
end 
of 
zone 
2
All 
kinds
 (Alkynes) 
of 
trees 
(threes/triple 
bonds) 
in
 the
night
 rile
 (nitrile) 
me 
in
zone 
3
Carbonyl
 in 
zone
 four
 is
 the
 biggest 
peak, 
hard
core.
If 
we 
were 
all 
keen
 (Alkene) 
we 
would
 all 
buy 
a
Mercedes 
Benz (Benzene) 
to 
drive 
to 
zone 
5