Prof. Dr. Fabio Simonelli | site das disciplinas

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Problem 1 7UDQVODWHG IURP $UW YDQ GHU (VW�

Using the chemical shift rules for CH-, CH2- und CH3-Groups draw the stick spectrum for propionic acid chloride. There is no shift rule for acid chloride groups. Search for an acceptable alternative.


Problem 2 �7UDQVODWHG IURP $UW YDQ GHU (VW�

4.0

3.5

3.0

2.5

2.0

1.5

1.0

ppm

C4H

8O2

(1 H; 2

50.1

3 M

Hz)

Exercises, problem 2: Determine the structure. Note that the integrals have been shifted a few millimeteres to the left for clarity.



0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

ppm

C3H

9N(1 H

; 250

.13

MH

z)

Exercises, problem 3: Determine the structure! Explain the splitting patterns! How large do the coupling constants have to be? Estimate the chemical shifts using the appropriate shift rules!



4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0ppm

131

9.95

131

2.86

130

5.78

634

.36

627

.13

619

.70

612

.65

605

.53

597

.95

317

.18

309

.73

301

.91

Hz

(1H ; 300 M H z)

C 3H 7N O 2

Exercises, problem 4: Determine the structure. Why is a clean sextet observed at 2 ppm? What is the actual multiplicity? The data are from a collection of the Pacific Lutheran University, Washington.


Problem 5 7UDQVODWHG IURP $UW YDQ GHU (VW�

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

ppm

(1 H; 2

50.1

3 M

Hz)

Exercises, problem 5: During the photo-chlorination of toluene, a mixture of products is obtained. Using the proton spectrum, determine the two components! In what mole ratio are the present?



4.5 4.0 3.5 3.0 2.5 2.0 1.5ppm

1.00

6.12

3.02

Inte

gral

C 4H 10O 2

(1H ; 250 .13 M H z)

Exercises, problem 6: Determine the structure. Note that the integrals have been shifted a few millimeteres to the left for clarity.



4.0

3.5

3.0

2.5

2.0

1.5

1.0

ppm

6x

C6H

12O

2

(1 H; 2

50.1

3 M

Hz)

Exercises, problem 7: Determine the structure. Check the chemical shifts using shift rules!



4.04.55.05.56.06.57.07.5ppm

C 6H 6N 2O 2(1H ; 250.13 M H z)

5.45.65.86.06.26.46.66.87.07.27.47.67.88.08.2ppm

C 6H 6N 2O 2(1H ; 250.13 M H z)

45678ppm

C 6H 6N 2O 2(1H ; 250.13 M H z)

Exercises, problem 8: Distinguish the three isomers of a disubstituted benzene derivative! Also interpret the chemical shift of the broad Signal! Which solvent was used?



1.01.52.02.53.03.54.04.55.05.56.06.57.07.5ppm

Inte

gral

1.00

1.06

1.08

1.57

4x

C 9H 9O C l(1H ; 250.13 M H z)

Exercises, problem 9: Determine the structural formula using the NMR-spectrum and the molecular formula!

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4567ppm

4x C 7H 7O C l(1H ; 250.13 M H z)

Exercises, problem 10: Determine the structure!



6.0

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

ppm

Hz

2449.222441.81

1890.421874.32

1714.001706.60

1690.501687.95

C9H

7NO

3

(1 H; 2

50.1

3 M

Hz)

Exercises, problem 11: Determine the structure and the conformation!



(1H ; 250.13 M H z)

2.8 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6ppm

583.

7957

6.42

569.

19

506.

30

392.

9138

5.49

378.

0837

0.61

363.

3335

6.07

210.

3920

3.00

195.

59

Hz

C 5H 10O(13C {1H }; 62.9 M Hz)

200 180 160 140 120 100 80 60 40 20ppm

208.

8

77.5

77.0

76.5

45.4

29.6

17.1

13.4

ppm

Exercises, problem 12 (page 1): Determine the structure of the two structural isomers (see additional spectra on second page)!


C 5H 10O(13C {1H }; 62 .9 M H z)

200 180 160 140 120 100 80 60 40 20ppm

212.

0

77.5

77.0

76.5

35.3

7.7pp

m

(1H ; 250.13 M H z)

2.8 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6ppm

600.

6259

3.24

585.

8557

8.53

253.

0924

5.77

238.

36

Hz

Exercises, problem 12 (page 2): Assign all of the signals in the spectra on this page!



3.8

3.6

3.4

3.2

3.0

2.8

2.6

2.4

2.2

ppm

(1 H; 2

50.1

3 M

Hz)

2.8

2.9

3.0

3.1

3.2

3.3

3.4

3.5

3.6

ppm

(1 H; 2

50.1

3 M

Hz)

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

3.2

3.4

ppm

(1 H; 2

50.1

3 M

Hz)

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

ppm

(1 H;

250.

13 M

Hz)

6.0

5.5

4.5

5.0

ppm

(1 H; 6

0 M

Hz;

sim

ulie

rt n

ach)

Orig

inal

date

n)

Exercises, problem 13: The 6 spectra correlate with the following structural formulae: CH3-CH2-OH, Cl2CH-CH2-CHCl2, (CH3)2-CH-CN, CHCl2-CHCl-CHCl2, CHCl2-CHO, N≡C-CH2-CH2-Cl, CHCl2-CHCl2, CH3-CH2-Cl, CH2Br-CH2-CH2Br, CH3-CH2Br, CH3-CHCl2 und (CH3)2-CHCl. Assign them correctly and explain your choice!



123ppm

C 6H 14O(1H ; 250.13 M H z)

Exercises, problem 14: Determine the structure. Hint: Work out the multiplicity of the multiplets at about 3.6 ppm! How can this be explained?



23

45

6pp

m

4x

C8H

10O

(1 H; 2

50.1

3 M

Hz)




2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

ppm

C8H

7ClO

(1 H; 2

50.1

3 M

Hz)

Exercises, problem 16: Determine the structure! Can you distinguish reliably between the two alternative structures?



3.54.04.55.05.56.06.57.07.58.0ppm

Inte

gral

1.00

1.4

9

4x

C 9H 10O 3

(1H ; 250.13 M H z)




234567ppm

4x

C 12H 14O 4(1H ; 250.13 M Hz)

8 7 6 5 4 3 2ppm

1.00

1.01

1.52

Inte

gral

4x

C 12H 14O 4

(1H ; 250 .13 M H z)

Exercises, problem 18: Determine the structures of the two isomers! Compare the spectra! (solvent: CDCl3)



1 .02 .03 .0ppm

2x

C 6H 14O(1H ; 250.13 M H z)

Exercises, problem 19: Work out the structure!



1336

.13

1334

.95

1333

.77

1332

.59

1319

.30

1318

.12

1316

.94

1315

.76

1289

.26

1288

.71

1288

.11

1287

.51

1286

.97

1279

.35

1278

.79

1278

.20

1277

.60

1277

.06

1526

.56

1519

.21

1516

.64

1511

.88

1509

.73

1509

.30

1502

.38

1501

.98

1499

.82

1495

.05

1492

.46

1485

.14

985.

478

984.

926

984.

303

983.

752

978.

139

977.

584

976.

964

976.

410

C 3H 5B r(1H ; 250.13 M H z)

Exercises, problem 20 (page 1): Determine the structure! Determine and explain all coupling constants! Use only the 250 MHz-Spectrum!


3030

.90

3023

.54

3020

.96

3016

.20

3014

.08

3013

.61

3006

.72

3006

.28

3004

.13

2999

.37

2996

.77

2989

.43

2661

.99

2660

.80

2659

.62

2658

.45

2645

.16

2643

.97

2642

.79

2641

.62

2571

.94

2571

.37

2570

.79

2570

.20

2569

.64

2562

.00

2561

.44

2560

.85

2560

.27

2559

.71

1965

.89

1965

.32

1964

.69

1964

.12

1958

.54

1957

.97

1957

.34

1956

.77

C 3H 5B r(1H ; 500 .14 M H z)

Exercises, problem 20 (page 2): The compound is the same as on page 1. Note the effect of the different measuring frequency on the shape of the multiplet!


Problem 21 �7UDQVODWHG IURP $ODQ .HQZULJKW�

23456ppm

4x

C 7H 8O(1H ; 250.13 M H z)

Exercises, problem 21: Determine the structure. Hint: You need to consider some unlikely (impossible?) structures!



20 0 18 0 16 0 14 0 12 0 10 0 80 60 40 ppm

198.

60

128.

4912

8.17

127.

84

30.4

3

ppm

C xH yO z

(13C {1H }; 75 M H z)

2781

.827

79.1

2776

.127

73.6

Hz

469.

946

6.9

Hz

9 .0 8.0 7.0 6.0 5.0 4.0 3.0 2.0ppm

C xH yO z

(1H ; 300 M H z)

10 x

Exercises, problem 22: Determine the Structure of the molcule! Which solvent was used? (The FIDs and the spectra are from a data collection at the Widener University, Chester)



5.4

5.5

5.6

5.7

5.8

5.9

6.0

6.1

6.2

6.3

ppm

Hz

1560.831559.93

1543.011542.11

1520.991520.091509.291508.39

1425.20

1413.511407.37

1395.68

C3H

3N(1 H

; 250

.13

MH

z)

Exercises, problem 23: Determine the structure! Make correct stereo chemical assignments for all protons! Determine the magnitude of all coupling constants!



6.5 3.54.04.55.05.56.07.0ppm

C 6H 7N(1H ; 250.13 M H z)

7.27.37.47.57.67.77.87.98.08.18.2ppm

C 6H 5N O 2(1H ; 250.13 M H z)

Exercises, problem 24: Which two singly substituted benzene derivatives are present? Estimate the chemical shifts using shift rules! Take note of (but do not interpret) the complicated splitting pattern!



3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

ppm

A

A

B

B

C

C

4x

C8H

9ClO

(1 H; 2

50.1

3 M

Hz)

Exercises, problem 25: Determine the structure! Assign all proton signals! Use shift rules and the expanded region! Corresponding multiplets are marked with the same letters in the main spectrum and the expanded regions.



3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

ppm

C8H

6(1 H

; 250

.13

MH

z)




2345ppm

4x

C 5H 9N O 4(1H ; 250 .13 M H z)

Exercises, problem 27: Using the 1H-NMR spectrum and the empirical formula determine the structure of the compound! Note: - The method of synthesis precludes the formation of a peroxide. - The compound is colourless.



23

45

67

ppm

4x

??

C9H

10O

3(1 H

; 250

.13

MH

z)

Exercises, problem 28: Which compound is shown here? Which acid-free solvent was used?



0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

ppm

C8H

9BrO

(1 H; 2

50.1

3 M

Hz)

Exercises, problem 29: Determine the structure! Which solvent was used?



23456ppm

Hz

1235

.712

32.0

1229

.212

25.6

1222

.812

19.1

1216

.412

12.7 475

.8

378

.2 3

71.7

C 8H 10O(1H ; 250.13 M H z)

Exercises, problem 30: Determine the structure. Hint: Start by considering from which group the signal at about 1.9 ppm arises.

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Prof. Dr. Fabio Simonelli | site das disciplinas