Prof. Paul Rablen and his research collaborator Prof. Thomas Bally at the University of Fribourg in Switzerland have been awarded a grant from the Swiss National Science Foundation which will allow Prof. Rablen to spend three months working at the University of Fribourg on a project concerning the calculation of proton-proton NMR coupling constants. Below is a brief profile:

Benchmarking the calculation of proton-proton NMR coupling constants via electronic structure theory using different density functionals and basis sets.

Donor: Swiss National Science Foundation, International Short Research Visits

Award Date: 1/5/2010

Nuclear magnetic resonance (NMR) spectroscopy provides one of the most powerful means to explore the structures of organic compounds in the laboratory. One-dimensional proton NMR spectroscopy, which is the simplest and most common version of NMR, provides primarily two kinds of information: chemical shift values and coupling constants. However, even for relatively simple molecules, analysis of the experimental chemical shift values and coupling constants is not always straightforward or unambiguous. Such analysis is often aided by comparison to chemical shift values and coupling constants predicted by quantum mechanical calculations. Many of these calculational methods have only become widely available and practical in the fairly recent past, and so it is of interest to test their accuracy in a systematic matter. Over the past two years, Paul Rablen (Swarthmore College) and Thomas Bally (University of Fribourg) have explored the reliability of proton chemical shift calculations. They found that even fairly modest levels of calculation (ones not requiring too much computer time and memory), if properly selected, yield excellent results. This grant from the Swiss National Science Foundation will enable Paul Rablen to spend three months at the University of Fribourg, where he and Professor Bally will continue and extend their collaboration. They will now focus on the calculation of coupling constants, which have to date been the subject of considerably less attention than calculated chemical shift values.

Project Period: 9/13/2010 - 12/11/2010