IR ABSORPTION BANDS

Question 1

O-H (alcohols)

Answer 1

3600-3000 (strong and broad)

Question 2

O-H (carboxylic acids)

Answer 2

3100 -2600 (very broad)

Question 3

N-H

Answer 3

3500-3100 (medium and broad)

Question 4

sp C-H

Answer 4

3300 (sharp)

Question 5

sp^2 C-H (alkene)

Answer 5

3100 (sharp)

Question 6

sp^2 C-H (aldehyde)

Answer 6

2850-3100

Question 7

sp^3 C-H

Answer 7

2950-2850

Question 8

C=-C (C-3bonds-C)

Answer 8

2260-2100 (weak intensity)

Question 9

C=O (carbonyls)

Answer 9

1800-1650 (narrow)

Question 10

C=C

Answer 10

1650-1550 (medium)

Question 10

C=O (ketone and aldehyde)

Answer 10

1720

Question 10

C=O (carboxylic acid)

Answer 10

1740

Question 11

C-O

Answer 11

1250-1050

Question 12

C=O (amide)

Answer 12

1660

Question 13

double bond region

Answer 13

1850-1630

Question 14

if double bond is present at _____
- look for aldehyde at: _____
- look for a carboxylic acid: _____
- look for ester _______
If C=O present, but nothing else, probably a ______

Answer 14

1. 1850-1630
2. two weak bands 2900-2700
3. broad band, 3200-2500
4. two bands, usually strong, 1300-1000
5. ketone

Question 15

Triple Bond region
Nitrile vs Alkyne Intensity

Answer 15

2280-2199
Nitrile: Strong
Weak: Alkyne