Teaching and Learning 1H Nuclear Magnetic Resonance Spectroscopy

Abstract

The present state of modern organic chemistry is in part due to the advent of nuclear magnetic resonance (NMR) spectroscopy. This analytical technique has transformed the field from one that previously relied on macroscopic properties when determining chemical identity to one that does so almost exclusively through the spectroscopic characterization of molecular structure. In addition to its transformative role, NMR spectroscopy is essential for future advancements in the field. Though its disciplinary value is undeniable, NMR spectroscopy is unfortunately difficult to both teach and learn. This difficulty is compounded by a general lack of chemistry education research on teaching and learning this technique, which in turn results in a lack of evidence-based instruction that cultivates relevant expertise. The work presented herein constitutes some of the first research on teaching and learning NMR spectroscopy. Specifically, this research focuses on 1H NMR spectroscopy, an application of the technique widely used by organic chemists. This work, guided by a number of research questions, provides insight that will serve to transform undergraduate and graduate-level instruction to effectively foster expertise in this practice. Among these questions were: (1) How do undergraduate and doctoral chemistry students develop expertise in 1H NMR spectral interpretation; (2) What knowledge do teaching assistants have for teaching 1H NMR spectroscopy, and how does this knowledge develop; and (3) Can we develop an assessment in 1H NMR spectroscopy that supports undergraduate instruction? Studies to investigate these questions drew from several theoretical and conceptual frameworks from the fields of education and cognitive psychology. Further, these studies incorporated a range of data collection methods, including eye tracking, interviewing, and surveys. Eye-tracking data were analyzed quantitatively, and interview and survey data were analyzed using a combination of qualitative and quantitative methods. Findings from the studies on developing expertise suggest that multiple areas of understanding are necessary for interpreting 1H NMR spectra, where progress in understanding corresponds to increasing knowledge of experimental and implicit chemical variables. More sophisticated understanding then facilitates an efficient and selective focus on features relevant for decision making. Further, less sophisticated understanding involving the overgeneralization of learned principles presents a significant barrier to learning when this inaccurate knowledge is used in combination with rule-based, shortcut reasoning strategies. These findings suggest that instruction should be designed to cultivate understanding across the identified areas, to promote the selective processing of relevant information, and to shift novices from rule-based, shortcut reasoning to analytical thinking that involves evaluating multiple underlying variables. Findings from the studies on instructors’ knowledge and assessment development provide instructors with additional guidance for providing effective instruction. In our investigation, teaching assistants appeared to lack knowledge of evidence-based instructional strategies to shift undergraduates to analytical thinking, indicating that this population of instructors may require targeted training to adequately support undergraduates’ learning. Further, the successful development of an assessment that measures students’ ability to communicate about 1H NMR spectra provides undergraduate instructors with a tool they can use to give feedback that promotes learning. Insight afforded by this body of foundational research has considerable, specific implications for reforming instruction on 1H NMR spectroscopy, all of which are summarized in detail in the closing remarks.