NMR Insights from Alex Blom, PhD, Alverno College

Answer: Dr. Blom: Before purchasing the picoSpin our department did not have NMR instrumentation. The fundamental theory and interpretation of spectra has been taught in our organic chemistry curriculum for years. Our physical chemistry sequence delves deeper into the mechanism of nuclear magnetic resonance and also incorporates computational chemistry NMR shift predictions to confirm spectral interpretation. We wanted to be able to get students hands-on experience with an instrument of this sort since they are used extensively in graduate schools and industry.

Dr. Blom: Our criteria included (not in any specific order):

• Low cost (under $100,000)
• Permanent magnet (eliminates cooling costs and the hazards associated with an extended magnetic field)
• Small footprint: lab space is limited and most NMR units take up a lot of space
• Consumable cost
• How much supervision will students require?
• How much training will faculty need?
• Data analysis difficulty
• Resolution
• Quality of customer support

Answer: Dr. Blom: The picoSpin has been integrated into the physical chemistry and organic chemistry curriculum thus far. In organic chemistry, students perform multi-step syntheses as individual investigations. They select procedures from various sources, including the Journal of Chemical Education, and tailor them to fit the available equipment and reagents available within the laboratory. They use various methods, including NMR spectroscopy, to characterize products along the steps within the synthesis. Projects this year included synthesis of fragrant esters, methone, phenacetin and others. The picoSpin was used extensively by students in this course to confirm successful production of the desired substances.

In physical chemistry, students have used the picoSpin in multiple laboratories. In one laboratory they are given unknowns and are asked to characterize them spectroscopically using the various methods available in the lab including NMR and FTIR. Students then interpret their spectra to determine the structure of their unknown. Another laboratory has students looking for evidence of hydrogen bonding. They are allowed to use any method desired (UV/Vis, FTIR, NMR, GC, HPLC) that they think will help them find evidence of hydrogen bonding. One particular project where the picoSpin was useful was the keto-enol tautomerization of acetylacetone. The student was able to definitively show the difference in the two tautomers in different solvents and the intramolecular hydrogen bond present in the enol form was clearly observed.

Dr. Blom: We are very happy with the instrument so far. Its ease of use allows students and faculty to learn how to use it very quickly. This gives students the confidence to collect NMR data almost as easily as FTIR data. My colleagues and I are impressed that the small instrument collects such great data and NMR tubes are not required. The benchtop NMR will likely become more popular in chemical education as it makes collection of data very simple compared to a traditional instrument and presents a low cost, yet viable, solution to those institutions looking for this type of instrument.

Interview date: June 26, 2014