Frequencies of IR and NMR

Question 1

What is the frequency of an N-H (amide) bond in IR spectroscopy?

Answer 1

3150-3350 cm^-1

There is one band if secondary, two bands if primary.

Question 2

What is the frequency of an N-H (amine) bond in IR spectroscopy?

Answer 2

3300-3450 cm^-1

There is one band if secondary, two bands if primary.

Question 3

What is the frequency of an O-H (carboxylic acid) bond in IR spectroscopy?

Answer 3

2450-3450 cm^-1

Question 4

What is the frequency of an O-H (alcohol) bond in IR spectroscopy?

Answer 4

2950-3450 cm^-1

Question 5

What is the frequency of a C-H (sp) bond in IR spectroscopy?

Answer 5

3250-3350 cm^-1

Question 6

What is the frequency of a C-H (sp²) bond in IR spectroscopy?

Answer 6

3050-3150 cm^-1

Question 7

What is the frequency of a C-H (sp³) bond in IR spectroscopy?

Answer 7

2800-3000 cm^-1

Question 8

What is the frequency of C≡C bond in IR spectroscopy?

Answer 8

2150-2300 cm^-1

Question 9

What is the frequency of C≡N bond in IR spectroscopy?

Answer 9

2200-2300 cm^-1

Question 10

What is the frequency of a C=C (alkene) bond in IR spectroscopy?

Answer 10

1620-1680 cm^-1

Question 11

What is the frequency of a C=C (aromatic) bond in IR spectroscopy?

Answer 11

1450-1610 cm^-1

Question 12

What is the frequency of a C=O (ester) bond in IR spectroscopy?

Answer 12

1735-1750 cm^-1

Question 13

What is the frequency of a C=O (aldehyde) bond in IR spectroscopy?

Answer 13

1720-1740 cm^-1

Question 14

What is the frequency of a C=O (carboxylic acid) bond in IR spectroscopy?

Answer 14

1700-1725 cm^-1

Question 15

What is the frequency of a C=O (ketone) bond in IR spectroscopy?

Answer 15

1705-1725 cm^-1

Question 16

What is the frequency of a C=O (amide) bond in IR spectroscopy?

Answer 16

1630-1680 cm^-1

Question 17

What is the chemical shift of a C=O bond in ¹³C NMR spectroscopy?

Answer 17

150-200 ppm.

Question 18

What is the chemical shift of a C=C (aromatic or alkene) bond in ¹³C NMR spectroscopy?

Answer 18

100-150 ppm.

Question 19

What is the chemical shift of a C-O bond in ¹³C NMR spectroscopy?

Answer 19

50-100 ppm.

Question 20

What is the chemical shift of a C≡C bond in ¹³C NMR spectroscopy?

Answer 20

65-90 ppm.

Question 21

What is the chemical shift of a C-Br, C-Cl or C-N bond in ¹³C NMR spectroscopy?

Answer 21

25-75 ppm.

Higher electronegativity leads to higher values.

Question 22

What is the chemical shift of a C-C=O bond in ¹³C NMR spectroscopy?

Answer 22

35-60 ppm.

Question 23

What is the chemical shift of a C-alkyl bond in ¹³C NMR spectroscopy?

Answer 23

0-50 ppm.

Question 24

What is the chemical shift of an primary alkyl hydrogen atom in ¹H NMR spectroscopy?

Answer 24

0.8-1.3 ppm.

Question 25

What is the chemical shift of an secondary alkyl hydrogen atom in ¹H NMR spectroscopy?

Answer 25

1.3-2 ppm.

Question 26

What is the chemical shift of an C≡C-H atom in ¹H NMR spectroscopy?

Answer 26

1.9-3 ppm.

Question 27

What is the chemical shift of an C=(O)-C-H atom in ¹H NMR spectroscopy?

Answer 27

2.2-2.8 ppm.

Question 28

What is the chemical shift of an Ph-C-H atom in ¹H NMR spectroscopy?

Answer 28

2.5-3 ppm.

Question 29

What is the chemical shift of an N-C-H atom in ¹H NMR spectroscopy?

Answer 29

2.4-2.7 ppm.

Question 30

What is the chemical shift of an C-O-C-H atom in ¹H NMR spectroscopy?

Answer 30

3.3-3.7 ppm.

Question 31

What is the chemical shift of an C(=O)-O-C-H atom in ¹H NMR spectroscopy?

Answer 31

4-4.5 ppm.

Question 32

What is the chemical shift of an Cl-C-H atom in ¹H NMR spectroscopy?

Answer 32

3.6-4.2 ppm.

Question 33

What is the chemical shift of an C(=O)-N-C-H atom in ¹H NMR spectroscopy?

Answer 33

3.2-3.5 ppm.

Question 34

What is the chemical shift of an C=C-H atom in ¹H NMR spectroscopy?

Answer 34

4.5-6 ppm.

Question 35

What is the chemical shift of an Ph-H atom in ¹H NMR spectroscopy?

Answer 35

6-9 ppm.

Question 36

What is the chemical shift of an C(=O)-H atom in ¹H NMR spectroscopy?

Answer 36

9.4-10.5 ppm.

Question 37

What is the chemical shift an C(=O)-OH atom in ¹H NMR spectroscopy?

Answer 37

10-13 ppm.