18. Nuclear Magnetic Resonance Spectroscopy

Nuclear Magnetic Resonance (NMR) is a spectroscopic technique widely used by organic chemists. NMR provides details about the location, number and environment of specific types of atoms within a sample. The proper interpretation of this information allows detailed chemical structures to be discerned. The same basic instrumentation used in this week’s experiment is used in physician offices when running MRI (magnetic resonance imaging) of body parts. NMR is a relatively recent invention. The very first commercial NMR was produced in 19521 and large research universities began acquiring and using NMR by the early to mid 1970’s. Many universities still do not have their own NMR machines due to their significant expense. A state of the art 600 MHZ NMR can easily cost 2 million dollars and a ‘relatively inexpensive’ educational 300 mHz may be obtained for approximately $600,000. Your instructor will give a lecture on the practical skills needed to properly interpret 1H NMR and 13C NMR spectra. A number of problems will be worked through together in the class. A separate set of problems will be given during the class to solve on your own or in small groups. Your daily grade will be assigned based on this problem set. Each student will be assigned an unknown sample. Each student will run their unknown on the 60 MHz NMR and obtain a 1H NMR spectra. The empirical formula, IR, and 13C NMR will be provided for each unknown. The interpretation of the data will result in a chemical structure being assigned to the unknown. In lieu of a lab report for this experiment, each student will complete a provided data sheet for their unknown. This data sheet is due at the beginning of the next lab.