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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).
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1) Aerobic Oxidation Crude Product Mixture 1H-NMR
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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
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.
5
2) Compound 2 (C8H14O4): IR
6
2) Compound 2 (C8H14O4): EI-MS
174
129
29
73
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
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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.
9
3) Compound 3 (C15H23ClO2S): IR
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3) Compound 3 (C15H23ClO2S): EI-MS
302 303
304
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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
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-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
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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.
14
4) Compound 4 (C11H14O2): IR
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4) Compound 4 (C11H14O2): EI-MS
178
133
105
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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)