Organic Chemistry 201

Exercises in Proton NMR

 

In this set of exercises you will

a) predict the number of proton NMR signals a compound will give

b) predict the number of signals and visualize the spectra for a set of 10 compounds

c) Match the 10 compounds referenced in b (above) to their corresponding proton NMR spectra

There is extensive feedback to explain each answer.

 

I. Draw the structure of each of the following compounds on a sheet of paper and then perform the following two tasks:

 

NMREx1c.gif

CH3CH2CH2-NO2

 1. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

NMREX2v23gif.gif

CH3CCl3    

 2. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

NMREx3anim.gif

BrCH2CH2CH2Br

 3. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

                                                                    ‌                                

NMREx4anim.gif

 4. For the cyclopropane indicate the number of signals that would appear in its proton NMR spectrum.  Check the feedback for a discussion of the answers.

 

NMRExanimv2.gif

NMREx5a.gif

 5. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.  

 

 

NMREx6aanim.gif

NMREx6a.gif

 6. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

  

NMRExanimv3.gif

NMREx7a.gif

 

 7. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

NMREx8aanim,.gif NMREx8a.gif

 

 8. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

 

 NMREx9anim.gifNMREx9a.gif

 9. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

  

NMREx10anim.gif

NMREx10a.gif

 10. For the following compound indicate the number of signals that would appear in its proton NMR spectrum

 

 

NMREx11anim.gif

NMREx11a.gif

 11. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

NMREx12anim.gif

NMREx12a.gif

 12. For the following compound indicate the number of signals that would appear in its proton NMR spectrum.

 

 

II. Chemical Shifts Chart:

 Chemshiftchartv2part1sp2010.gif

 

Chemshiftchartv2part2sp2010.gif

 

 

III. The following structures (a through j) correspond to the simulated proton NMR spectra shown below in section V of this document. For each compound, predict the number of proton NMR signals it will show and predict what its proton NMR spectrum will look like: 

 

NMRExspeca.gif

IV. The following problems (1a through 2c), pertain to compounds a and b above; they present some sample approaches to predicting the appearance of the spectrum of a compound: 

 1a. How many signals does the H-1 NMR spectrum of compound a have?  

 1b. Give the approximate chemical shift(s) of the signal(s) in the H-1 NMR spectrum of compound a.

 1c. Which of the following statements is true about the splitting pattern of compound a?

 2a. How many signals are in the H-1 NMR spectrum of compound b?

 2b. Give the approximate chemical shift(s) of the signal(s) in the H-1 NMR spectrum of compound b.

 2c. Which of the following statements is true about the splitting pattern of compound b?

 

V. In scrambled order, the following are the simulated proton NMR spectra of compounds a through j which are shown above. Match each compound to the corresponding spectrum, and then check your work by answering the questions which follow in section VI below. Detailed feedback accompanies each question.

SpectraforNMREX1stset.gif

SpectraforNMREX2ndset.gif

  VI. In each of the following questions you will match the Spectrum to the corresponding compound , a through j.

 To which of the compounds, a through j, does Spectrum 1 correspond?

 To which of the compounds, a through j, does Spectrum 2 correspond?

 To which of the compounds, a through j, does Spectrum 3 correspond?

 To which of the compounds, a through j, does Spectrum 4 correspond?

 To which of the compounds, a through g, does Spectrum 5 correspond?

 To which of the compounds, a through j, does Spectrum 6 correspond?

 To which of the compounds, a through j, does Spectrum 7 correspond?

 To which of the compounds, a through j, does Spectrum 8 correspond?

 To which of the compounds, a through j, does Spectrum 9 correspond?

 To which of the compounds, a through j, does Spectrum 10 correspond?