NMR Lab – Dry Lab

In this experiment you will learn to use our proton NMR spectrometer and gain experience in analyzing NMR
spectra. There are 8 unknowns for this experiment. They are identified by the color of the cap on the NMR
tube. Each unknown has been dissolved in CDCl3 with added TMS according to the procedure described in
Pavia 5th ed., starting on page 898. If you are asked to prepare a sample, you will follow the same procedure.
The instructor will demonstrate the operation of the instrument by running the standard unknown according to
the Directions for Operation of the NMR handout. Each student must run at least one FT-NMR spectrum of a
different unknown in the same manner, have it signed by the instructor, and submit it with this cover sheet. The
other unknowns can either be originals or Xerox copies of approved spectra run by other students. You will use
the spectra together with any additional information supplied to identify the unknowns.
Consider the chemical shifts, splitting patterns and relative numbers of each kind of hydrogen obtained from
the NMR spectrum together with any other data supplied by the instructor (molecular formula, IR information,
etc.) to determine the structure of each unknown. For each unknown, give a brief summary of your reasoning in
the space provided below and draw a structure for the compound. If you are unable to determine the structure
of the unknown, tell as much about the compound as possible. Draw the Lewis structure of each unknown on
its NMR spectrum and clearly match each resonance with its respective hydrogen(s).