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Hugh Thompson email:
hwt@rutgers.edu
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Research Interests
Our interests center on the architecture of medium-sized molecules and the resulting stereochemistry of their reactions in solution and at catalyst surfaces as well as their solid-phase hydrogen-bonding patterns. One of our long-term projects involves control of alkene-reduction stereochemistry, using functional groups within the substrate molecule. Rather that influencing stereochemistry merely by hindrance, some groups have attractive interactions by which a reagent or a catalytic surface is actively led to a particular face of the alkene, allowing a chemist to control reduction stereochemistry by manipulating this functional group. Our research has examined the extent and synthetic usefulness of this effect in a variety of substrate systems.A second topic of interest is impacted-electron systems, whose geometry forces non-bonded or pi orbitals into close proximity, and may allow electron transfer across spaces lacking formal bonds. A typical question is how the acidity of a carboxyl group in such a molecule will respond to the presence of a strongly electron-withdrawing group, e.g., nitro, at an attached site with no direct conjugative links.
In a collaborative study, we also are examining hydrogen-bonding modes in crystalline keto carboxylic acids. Simple carboxylic acids normally exist as H-bonded dimers, and for keto acids this is the commonest solid-state arrangement, with the ketone not involved. However, by X-ray crystallography we have found the H-bonding modes of many keto acids to involve infinite chains formed by intermolecular acid-to-ketone H bonding. We also have found that because of symmetry properties of the dimers, coordinated use of IR and Raman spectroscopy accurately predicts the H-bonding structure of keto acids. Our research is aimed at elucidating the structural factors that govern the choice of solid-state H-bonding mode in those compunds. These appear to incude such controllable features as molecular flexibility and the presence or absence of enantiomers.