Peter Debye Award in Physical Chemistry

Sponsored by DuPont

An "unparalleled record of research and the remarkable impact he has had on diverse subfields" of theoretical and computational chemistry warrant the selection of chemistry professor Donald G. Truhlar of the University of Minnesota, Minneapolis, for this year's Peter Debye Award in Physical Chemistry, a colleague says.

Truhlar's achievements include his group's development of variational transition-state theory with multidimensional semiclassical tunneling contributions (VTST)-which represents "the single most important practical advance in theoretical chemical kinetics since the classical contributions of Henry Eyring in the 1930s," the colleague notes. VTST is a technique for studying electronically adiabatic reactions (reactions taking place entirely in the ground electronic state). Its development made it possible for Truhlar and coworkers to make the first full calculations of secondary kinetic isotope effects (SKIEs) in enzymes, and their theoretical prediction of an SKIE for dihydrofolate reductase has been confirmed experimentally.

Truhlar and his group also developed some of the earliest and most efficient direct dynamics techniques, in which electronic structure calculations are used directly in calculations of reaction rate constants-obviating the need to develop a potential energy surface for the reaction, which is a difficult and time-consuming process. A key aspect of this work is the inclusion of multidimensional quantum effects in the dynamics.

Truhlar and coworkers also developed accurate methods for applying quantum mechanical scattering theory to reaction dynamics. They used these methods to study the hydrogen exchange reaction (H + H₂) beginning in the 1980s, and they have since refined the treatment of the rate of that reaction considerably, so that it is now considered to be a fully solved problem. They also applied their methods to reactions of heavier atoms such as O, F, and Br (including exothermic reactions that yield inverted populations of the vibrational states), and to photochemical reactions.

In 1991, the researchers obtained and interpreted the quantum mechanical spectrum of a transition state. This was the first study to show how chemical reaction rates are globally controlled by quantized transition-state energy levels.

The group's work on potential energy surfaces has also been groundbreaking. Their 1978 potential energy surface for the hydrogen exchange reaction was the first quantitatively accurate one for any reaction, and they have modeled several more-complex reactions as well.

Truhlar and coworkers have also developed condensed-phase solvation models that are in wide use for modeling equilibria and dynamics in solution. This work culminated in the development of the first universal solvation models for predicting free energies of solvation and partitioning for arbitrary solutes in arbitrary solvents. Models they developed for charge distributions within molecules have also been widely used in modeling studies.

Truhlar, 61, earned a B.A. summa cum laude in chemistry at St. Mary's College, Winona, Minn., in 1965, and a Ph.D. in chemistry at California Institute of Technology in 1970. Since leaving Caltech, he has been on the faculty at the University of Minnesota—initially as an assistant professor and currently as Lloyd H. Reyerson Professor of Chemistry, Chemical Physics, Nanoparticle Science & Engineering & Scientific Computation.

The award address will be presented before the Division of Physical Chemistry.—Stu Borman