posted May 22, 2017
Pitt-Johnstown’s long-awaited Nuclear Magnetic Resonance Spectrometer (Bruker 400 MHz NMR) is up and running. The instrument was received in early 2017 and is housed in a specially designed NMR room on the second floor of the newly renovated Engineering and Science Building, is the property of the Chemistry Department.
The instrument replaces the aging 300 MHz model, which was acquired in 1998. The renovations to the Engineering and Science Building, the relocation of the Chemistry Department to a newer and larger space on the second floor, and the expanding research and teaching needs of the department provided a perfect opportunity to upgrade to a higher field instrument.
“Faculty have already used the NMR Spectrometer for research,” said Chemistry Department Chair Lisa Bell-Loncella, PhD. “In addition, students in the P-Chem lab measured the magnetic moment of some paramagnetic transition metal complexes while students in the Inorganic Synthesis and Characterization lab recorded spectra of some ruthenium complexes prepared this spring.”
NMR is used to characterize solids and liquids, qualitatively and quantitatively, small organic molecules, large metal coordination complexes, ionic liquids, molecular organic frameworks (MOFs) as well as large biological macromolecules, such as proteins, DNA, RNA and complexes of these molecules.
During the summer, several faculty will attend training sessions at the Bruker facility in Billerica, MA. Applications of NMR spectroscopy are being integrated into every course in the Chemistry curriculum beginning with Organic Chemistry. The primary users will be Chemistry and Biochemistry majors. However, students majoring in Biology, Chemical Engineering and Chemical Education as well as students preparing for professional programs in pharmacy, medicine and other health careers will use the instrument in Chemistry laboratory courses.
“Of all instrumental methods used by chemists, NMR provides the most information about the structure of a molecule or complex,” said Dr. Bell-Loncella. “The instrument is used in research to characterize molecules, specifically the physical and chemical properties of atoms or the molecules in which they are contained.“
The spectrum provides information about atom connectivity, bonding and molecular symmetry. Like many spectroscopic methods, NMR was originally developed by physicists. In the late 1940s and early 1950s, physicists Felix Bloch and Edward Purcell developed the method independently as part of their studies to investigate nuclear properties. The nucleus of every atom (of every element) contains one or more protons, charged particles which spin.
The NMR experiment is based on the premise that charged spinning particles placed in a magnetic field will align with (or against) the magnetic field. When the spinning charge is irradiated with electromagnetic energy of radio frequency, the spins will tip away from the magnetic field and precess around it while slowly relaxing back. The frequency at which the protons relax back to their equilibrium position depends on how the atoms are attached to one another.
While physicists and physical and inorganic chemists explored the range of nuclei that will give an NMR signal, organic chemists discovered that different functional groups resonate at different frequencies. This led to extensive libraries of spectra that aid in identifying the structure of new molecules. Pitt-Johnstown acquired a new Nuclear Magnetic Resonance Spectrometer, which is housed in the Engineering & Science Building. The NMR Spectrometer was obtained through University of Pittsburgh at Johnstown funding.