Structure Determination by Computation of 1H NMR Chemical Shifts

'This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).'

Nuclear magnetic resonance (NMR) spectroscopy is the single most important experimental technique used by chemists to deduce the structure of new organic compounds. It capitalizes on the fact that certain types of atomic nuclei, most importantly hydrogen (1H) and carbon (13C), are highly sensitive to their local chemical and magnetic environments. Thus, subtle differences in chemical structure at the molecular level are reflected in the spectroscopic characteristics of these nuclei, most importantly in the position that each atom absorbs energy in the NMR spectrum of that particular compound. This parameter is called the chemical shift, and each compound gives rise to a collection of unique chemical shift values. Advances in theoretical and computational chemistry have brought experts to the level of being able to compute NMR chemical shifts, and these theoretical spectral properties can then be applied to questions of structure. These developments have not yet been adopted by the broader community of experimentalists-the organic chemists who make or isolate new chemical substances on a daily basis and who, on occasion, are faced with challenging structure assignment problems.

The driving hypothesis statement for the proposed studies is: A reliable (and user-friendly)protocol for structure determination of small organic compounds,involving comparison of experimental 1H NMR chemical shift data sets with those computed for candidate structures, can be developed. Research is about process as well as product. The educational component of research is an integral and equally important element. The Hoye group appreciates the role that undergraduate research plays in sparking the scientific interests of young students. The group will involve both graduate and undergraduate students in this project, the latter to include some who will be recruited from one of the Community Colleges in the Twin Cities. The proposed studies lend themselves well to this plan. Overall, the group's record of dissemination and engagement is the best indicator that outcomes

from these studies will have broad impact.