Mark McClure

 “NMR Spectroscopy of Cobalt Complexes ”

My research interests focus on the application of NMR spectroscopy to the study cobalt (III) coordination compounds containing multidentate ligands. These types of systems represent an interesting challenge from an NMR standpoint. For ligands that contain carbon atoms, C-13 NMR can sometimes be used to determine the overall geometry of the complex ion. However, the H-1 NMR of these systems is often complex. This complexity arises from the fact that coordination restricts rotation about the carbon-carbon bonds of the ligand and therefore introduces nonequivalence in hydrogen atoms attached to the same carbon. As a result, even a simple ethylene linkage joining two donor atoms can contain up to four nonequivalent protons. This often results in very complex splitting patterns, and the interpretation of such spectra requires two-dimensional NMR techniques such as COSY and NOESY.