Bench-top, Indirect-detection Experiments for 13C-NMR Acquisition: Utilizing low-field NMR at a Primarily Undergraduate Institution

Abstract

In order to publish an article containing the synthesis of new molecules in a peer-reviewed research journal, accurate and reproducible NMR data must be obtained. For many Primarily Undergraduate Institutions (PUIs), obtaining or allocating infrastructure and resources for the acquisition and maintenance of a high-field NMR is impractical. Partnerships with local PhD-granting universities is the solution of choice for those research-oriented synthetic chemists working at PUIs. The challenge with these partnerships is often the time-cost of commuting to and from the location, the training of students, and the scheduling challenge associated with the walk-in nature of many instruments and monetary cost. In order to successfully utilize these partnerships, the principle investigator (PI) must often take time away from the high teaching load associated with PUIs. Any time spent at the distant NMR site without the students also subtracts from the valuable and essential mentoring time allotted to undergraduate researchers. Scheduling group field trips to the facility often complicate and lengthen the process further. Other obligations must also be rescheduled, reduced or eliminated altogether in order to arrive at the instrument in the early morning prior to graduate student use, or use the instrument on the weekend. These times are not ideal as troubleshooting is left up to the PI, with little help from the spectroscopist or instrumentation manager. These time-based challenges draw out the length of projects and often deny undergraduate students opportunities to perform synthesis-based research and the subsequent characterization adequate for undergraduate chemistry curriculum. Here we report the use of the MagriTek Spinsolve, a new, bench top, low-field NMR spectrometer, as it pertains to in-house, relatively low-concentration, 13C-NMR acquisition of three different compounds, in conjunction with teaching advanced NMR techniques to undergraduate researchers for complex structure elucidation.