Experiment 13 Identification of Unknowns using IR & NMR Report

C-C

C=C

C C

C C

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-H

C-N

C-N

C N

C-O

C-

N-H

C-

N-H

C-

O-H

C-

O-H

C-

O-H

C-X

C-X

C=O

C=O

C=O

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A

B

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C

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D

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E

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F

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G

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H

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I

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J

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K

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L

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M

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following 3 pages.

Experiment 2: NMR Spectroscopy

 

Part 2

(9

pts)

Nine compounds are drawn below. The NMR spectrum fo

r each is among the nine spectra on the

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Exp: 11: NMR Spectroscopy

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  1. Match each compound with its NMR.
  2. Draw the structure above the corresponding spectrum.
  3. Label each type of proton in the structure with a letter, and put the same letter over the corresponding peak on the NMR spectrum (see example below). Some NMR spectra show a peak hovering above the baseline. This is a magnified view of one of the actual peaks, to allow you to see

splitting more clearly.

  1. Write down one or two bands which you would look for in the IR spectrum of the compound to

verify your assignment.

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1

 

 

 

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2

 

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Exp: 11: NMR SpectroscopyExperiment 2: NMR Spectroscopy

 

 

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3

 

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Part 3

(2

pts)

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Part 2

The structures of ethyl butanoate and propyl butanoate are drawn below. Note how each has an ethyl group and a propyl group; the only difference is how they are orientated around the ester functional group. The way to distinguish between the carbons on either side of the ester group is by chemical shift: the carbon next to the oxygen will usually have a shift of 3-4 ppm, while the carbon next to the carbonyl will 1) Match each compound with its NMR.

usually have a shift of 2-3 ppm.

  1. Draw the structure above the corresponding spectrum.
  2. Label each type of proton in the structure with a letter, and put the same letter over the corresponding peak on the NMR spectrum.

p

 

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Note: Esters are named from their parent carboxylic acid. For example, ethyl butanoate is derived from butanoic acid and propyl propanoate is derived from propanoic acid.

 

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4

Exp: 11: NMR SpectroscopyExperiment 2: NMR Spectroscopy

 

Part 4

(8

pts)

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Part 3

The eight spectra on the following pages represent mono, di, and trisubstituted aromatic compounds. An example of each type of disubstituted compounds is represented: ortho, meta, and para subsituted. The 1) Match each compound with its NMR. You probably will not be able to tell an ortho from a meta structures of the compounds which correspond to the eight spectra are drawn below.

substituted compound; you will not be marked off if you have these wrong. You will be marked off if you mix up a para with an ortho or meta substituted compound. Remember, para compounds are

distinguished by their symmetric pair of doublets in the aromatic region.

2) Draw the structure above the spectrum and indicate which proton(s) correspond to which NMR

peak. You do not have to assign each proton on the aromatic ring to a specific peak in the NMR aromatic region—simply indicate that they are somewhere in the aromatic grouping of NMR peaks.

 

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5

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6

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Exp: 11: NMR SpectroscopyExperiment 2: NMR Spectroscopy

 

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7

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