IR Spec Numbers

What is the region for double bonds?

1600 - 1850 cm^-1

What is the region for triple bonds?

2100 - 2300 cm^-1

What is the region for EN atoms single-bonded to hydrogen atoms, i.e., X-H?

2700 - 4000 cm^-1

What can be found in Zone 1 (3700 - 3200 cm^-1)?

Alcohols (O-H), Amines/Amines (N-H), sp C-H peak (≡C-H)

What can be found in Zone 2 (3200 - 2700 cm^-1)?

sp² C-H peak, sp³ C-H peak, Aldehyde (C-H), Carboxylic acid (O-H)

What can be found in Zone 3 (2300 - 2000 cm^-1)?

Nitrile (C≡N) and Alkyne (C≡C)

What can be found in Zone 4 (1850 - 1650 cm^-1)?

Carbonyl functional groups (C=O)

What can be found in Zone 5 (1680 - 1450 cm^-1)?

Benzene ring and Alkene (C=C).

Ketone

1720 cm^-1

Conjugated ketone

1680 cm^-1

Amide

1660 cm^-1

Ester

1740 cm^-1

sp³ C-H bond

3300 cm^-1

sp² C-H bond

>3000 cm^-1

sp³ C-H bond

<3000 cm^-1

Primary Amine, how many peaks?

3300 - 3000 cm^-1, two peaks as a result of one carbon

Secondary Amine, how many peaks?

3300 - 3000 cm^-1, one peak as a result of two carbons

Alcohol

3600 - 3200 cm^-1 (broad)

Carboxylic acid

3600 - 2200 cm^-1 (very broad)

Aldehyde

2820 and 2720 cm^-1

Benzene ring

1600 cm^-1 (weak), 1500 - 1430 cm^-1 (strong), and several small peaks from 1700 - 1900 cm^-1

C≡C

2260 - 2220 cm^-1 (medium)

C≡N

2260-2100 cm^-1 (medium to weak)

C=C

1680 - 1600 cm^-1 (medium)

C=N

1650 - 1550 cm^-1 (medium)

C-O

1250 - 1050 cm^-1 (strong)

C-N

1230 - 1020 cm^-1 (strong)

Internal alkyne

Is IR inactive