at Texas A&M University

The Singleton Research Group

Welcome to the Singleton group website!

grp 2011

The Singleton research group carries out broad-based basic research in Organic Chemistry, including the study of a wide range of reaction mechanisms, the identification of mechanistically novel reactions, and the development of new organic reactions. The group’s projects make use of advanced laboratory experimental probes of mechanisms, augmented by theoretical calculations and physical organic analysis. In working on central problems in organic reactivity, group members develop both diverse experimental skills and a fundamental scientific understanding of organic chemistry.

A key tool that the group uses in its mechanistic studies is the determination of kinetic isotope effects (KIEs). These studies take advantage of methodology developed in the Singleton group for the high precision combinatorial determination of KIEs at natural abundance by NMR.

This methodology is 1-2 orders of magnitude faster than studies requiring labeling. It is also much more versatile, being applicable to a great number of reactions that would have been impossible to study in other ways. The simultaneous determination of a complete set of 13C, 2H, and 17O isotope effects possible with our methodology provides a much greater level of information than available from conventional methods. In combination with theoretical calculations, these KIEs provide an experimental basis for transition state geometry. The combination of our experimental methodology and theory has repeatedly been successfully applied to resolve controversies, to experimentally establish critical details of important reaction mechanisms, and to find new mechanisms for basic reactions.

isotope effs

Dynamic effects are kinetic phenomena associated with the motions and momenta of atoms that cannot be explained using transition state theory. The cutting edge in our group is the study of dynamic effects in ordinary reactions in solution. As we have studied reaction mechanisms, we have found that the conventional framework for understanding reactions using transition state theory is often not adequate, and we have found that dynamic effects play a role in organic reactions much more often than currently thought. In studying such reactions, our goal is to revise the fundamental understanding of reactivity and selectivity in organic chemistry.

dynamic effects