Assistant Professor of Chemistry Christian M. Rojas
Trip for NMR Training Course in Billerica, MA

As part of a program, sponsored by NSF and HHMI, to incorporate high-field NMR spectroscopy into Barnard’s undergraduate Chemistry curriculum, Christian Rojas attended a four-day training course at Bruker Instruments in Billerica, MA, October 16–19, 2000.  The course provided Rojas with working knowledge of the Barnard Chemistry Department’s new Avance 300 MHz NMR spectrometer, installed in August 2000.  Following the course, Rojas has been able to train faculty and students to use the NMR system, enhancing the Department’s ability to apply the new spectrometer for undergraduate chemistry education.

The training course in Billerica had both classroom and laboratory components.  Instructors provided an overview of X-Win NMR, Bruker’s spectrometer-operation software package.  File structure as well as acquisition and processing of data were discussed.  The Bruker software includes valuable tools for training of instrument users and for teaching.  ICON-NMR is an automated system for high-throughput of samples that we will use for running routine spectra in the organic teaching laboratory.  Also available is the Bruker NMR Guide/Encyclopedia, a hyper-linked guidebook that runs on a local web server and controls the spectrometer directly from a web-based environment. Using the NMR Guide/Encyclopedia, the spectrometer operator can access a detailed description of a particular NMR experiment and follow an annotated, step-by-step procedure for running the experiment, including acquisition, processing, and interpretation of data.  In the Bruker applications laboratory, Rojas gained hands-on experience using these tools and in setting up one- and two-dimensional NMR experiments.  Course attendees worked in small groups with Bruker applications specialists, allowing for close attention to individual requests for instruction.  For example, Rojas was able to learn about remote processing of data from the spectrometer, something that will maximize the amount of time spent for data acquisition, particularly in teaching laboratory settings.

In the fall of 2001, Rojas introduced new NMR experiments in the advanced organic laboratory course that utilize capabilities of the new NMR spectrometer system.  One of these involves the selective synthesis of organic molecules in a single mirror-image form.  The ability to make molecules in this enantioselective way is of great interest in medicinal chemistry, for example, because mirror-image molecules may have critically different biological activities.  Determination of reaction enantioselectivity will employ fluorine-19 NMR, using the new Avance 300 MHz system.  In a different experiment, students use two-dimensional spectroscopic techniques to deduce the exact spatial arrangement of chemical groups in the product of a chemical reaction. Students carry out a so-called Diels-Alder reaction, in which two products are possible. The two products are stereoisomeric - they possess the exact same atomic connectivities, differing only in the three-dimensional arrangement of those atoms in space.  A technique known as NOESY can elucidate the precise orientation of chemical groups with respect to each other.  Rojas ran this type of experiment in the Bruker training course and incorporated it into the Barnard teaching laboratory. Rojas has also trained other faculty at Barnard in use of the new spectrometer, and those chemists will introduce new experiments in courses on biochemistry, physical, and inorganic chemistry.

The NMR training course that Rojas attended at Bruker Instruments served as a starting point for new teaching initiatives in the Barnard Chemistry Department.  Opportunities in a variety of areas are under active development.  The NMR spectrometer is a key component of a laboratory-intensive chemistry curriculum.

 

 
 
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