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CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set...

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1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the 1 H-NMR spectrum of the crude reaction mixture from the aerobic oxidation reaction shown below. Use the standard labeling (Ha, Hb, Hc, etc.) shown in the NMR lectures and problem sets. Justify your assignments by use of the empirical parameters found in the appendix of the laboratory manual. Use the 1 H-NMR spectrum of the crude product mixture to determine the % conversion of this reaction with the assumption that there are no side reactions. (10 pts) 2) Use the supplied spectral data to identify Compound 2, C8H14O4. (12 pts) 3) Use the supplied spectral data to identify Compound 3 (a sulfonyl chloride) , C15H23ClO2S. (14 pts) 4) Use the supplied spectral data to identify Compound 4, C11H14O2. (14 pts) Questions 2 - 4 require you to use a combination of molecular formula, NMR and MS data in order to identify each unknown compound; use all data supplied and hand in all spectra for each question. Clearly provide your calculation of the unsaturation number (IHD, DBE) value for each compound. Draw all molecules or fragments directly onto the provided spectra. Show all lone pairs and charges for each structure. Write and sketch clearly! Label each set of equivalent protons using the Ha, Hb, Hc etc. labeling system shown in the 1 H-NMR lectures and practice problem sets. Assign each 1 H-NMR signal and write your assignments directly onto the spectrum. Justify your assignments by use of the empirical parameters found in the appendix of the laboratory manual. Identify each 13 C-NMR signal as either alkyl, vinyl, alkynyl, aryl, nitrile, imine, or carbonyl (you do not need to assign individual carbon atoms to each signal). Assign each key IR absorption band >1500 cm -1 to a specific functional group. Draw fragments for all labeled peaks in the EI-MS directly onto the spectrum (you do not need to show the fragmentation mechanism).
Transcript
Page 1: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

1

Name: CHEM 344 Spring 2014

Spectroscopy Problem Set

TA:

Due at start of discussion Monday the 30th June

1) Assign all signals in the 1H-NMR spectrum of the crude reaction mixture from the

aerobic oxidation reaction shown below. Use the standard labeling (Ha, Hb, Hc, etc.)

shown in the NMR lectures and problem sets. Justify your assignments by use of the

empirical parameters found in the appendix of the laboratory manual.

Use the 1H-NMR spectrum of the crude product mixture to determine the % conversion

of this reaction with the assumption that there are no side reactions. (10 pts)

2) Use the supplied spectral data to identify Compound 2, C8H14O4. (12 pts)

3) Use the supplied spectral data to identify Compound 3 (a sulfonyl chloride) ,

C15H23ClO2S. (14 pts)

4) Use the supplied spectral data to identify Compound 4, C11H14O2. (14 pts)

Questions 2 - 4 require you to use a combination of molecular formula, NMR and MS

data in order to identify each unknown compound; use all data supplied and hand in

all spectra for each question.

Clearly provide your calculation of the unsaturation number (IHD, DBE) value for each

compound.

Draw all molecules or fragments directly onto the provided spectra. Show all lone

pairs and charges for each structure. Write and sketch clearly!

Label each set of equivalent protons using the Ha, Hb, Hc etc. labeling system shown

in the 1H-NMR lectures and practice problem sets. Assign each 1H-NMR signal and

write your assignments directly onto the spectrum. Justify your assignments by use of

the empirical parameters found in the appendix of the laboratory manual.

Identify each 13C-NMR signal as either alkyl, vinyl, alkynyl, aryl, nitrile, imine, or

carbonyl (you do not need to assign individual carbon atoms to each signal).

Assign each key IR absorption band >1500 cm-1 to a specific functional group.

Draw fragments for all labeled peaks in the EI-MS directly onto the spectrum (you do

not need to show the fragmentation mechanism).

Page 2: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

2

1) Aerobic Oxidation Crude Product Mixture 1H-NMR

Page 3: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

3

2) Compound 2 (C8H14O4): 1H-NMR

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0

300 MHz ¹H NMRIn CDCl3

ALL RIGHTS RESERVED© 2014, Sigma-Aldrich Co.

4.19

1.00

3.06

6.12

4.19

Page 4: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

4

2) Compound 2 (C8H14O4): 13C-NMR

170.111

77.56777.146 76.726

61.313

46.191

14.070

13.553

0.000

200 180 160 140 120 100 80 60 40 20 0

75 MHz ¹³C NMRIn CDCl3

ALL RIGHTS RESERVED© 2014, Sigma-Aldrich Co.

Page 5: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

5

2) Compound 2 (C8H14O4): IR

Page 6: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

6

2) Compound 2 (C8H14O4): EI-MS

174

129

29

73

Page 7: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

7

3) Compound 3 (C15H23ClO2S): 1H-NMR

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

7 6 5 4 3 2 1 0

300 MHz ¹H NMRIn CDCl3

ALL RIGHTS RESERVED© 2014, Sigma-Aldrich Co.

2.00 2.04 1.05

17.65

6.28

2.04 1.05 11.65

Page 8: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

8

3) Compound 3 (C15H23ClO2S): 13C-NMR

155.539

150.298

124.243

77.40576.985

76.564

34.368

29.710

24.357

23.435

0.000

200 180 160 140 120 100 80 60 40 20 0

75 MHz ¹³C NMRIn CDCl3

ALL RIGHTS RESERVED© 2014, Sigma-Aldrich Co.

Page 9: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

9

3) Compound 3 (C15H23ClO2S): IR

Page 10: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

10

3) Compound 3 (C15H23ClO2S): EI-MS

302 303

304

Page 11: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

11

4) Compound 4 (C11H14O2): 1H-NMR

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

8 7 6 5 4 3 2 1 0

300 MHz ¹H NMRIn CDCl3

ALL RIGHTS RESERVED© 2014, Sigma-Aldrich Co.

4.00

2.03

3.01

2.08

3.06

4.00

Page 12: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

12

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

1.2

4.0 3.5 3.0 2.5 2.0 1.5

300 MHz ¹H NMRIn CDCl3

ALL RIGHTS RESERVED© 2014, Sigma-Aldrich Co.

2.03

3.01

2.08

3.06

Page 13: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

13

4) Compound 4 (C11H14O2): 13C-NMR

171.372136.745

132.880

130.260

130.082

127.268

126.038

77.47077.04976.629

60.698

39.268

19.537

14.184

0.000

200 180 160 140 120 100 80 60 40 20 0

75 MHz ¹³C NMRIn CDCl3

ALL RIGHTS RESERVED© 2014, Sigma-Aldrich Co.

Page 14: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

14

4) Compound 4 (C11H14O2): IR

Page 15: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

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4) Compound 4 (C11H14O2): EI-MS

178

133

105

Page 16: CHEM 344 Spectroscopy Practice Problem Set I...1 Name: CHEM 344 Spring 2014 Spectroscopy Problem Set TA: Due at start of discussion Monday the 30th June 1) Assign all signals in the

16

Last Name (print): ____________________________________ CHEM 344

Summer 2014

First Name (print): ____________________________________ Spectroscopy Problem Set

TA’s Name: __________________________________________

1) _______ (10 pts)

2) _______ (12 pts)

3) _______ (14 pts)

4) _______ (14 pts)

Total _______ (50 pts)

_______ (math double-check)


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