Texaco-Mangelsdorf Assistant Professor
B.A., Swarthmore College, 1983
NSF Graduate Fellow, 1983-1985
Amoco Foundation Fellow, 1987
NATO Postdoctoral Fellow, 1989
NSF Postdoctoral Fellow, 1989-1990
Darwin Research Fellow, Cambridge U., 1989-1990
Chemical Kinetics, Molecular Simulation, Free Radical Reactions
Chemical kinetic models are increasingly used as input for major business and public policy decisions, ranging from the design of chemical process units to energy tax proposals. Rapid advances in computer hardware and software now make it feasible to construct truly predictive kinetic models based on a detailed understanding of the molecular processes occuring in complicated systems, rather than the very empirical interpolative models typically used today. Our efforts are focused on the development, demonstration, and validation of new methods for predicting the course of chemical reactions, and on the application of these methods to important technological and policy problems.
We have recently developed a general algorithm for constructing compact but complete reaction schemes for multicomponent reacting mixtures, given a procedure for estimating all the reaction rate parameters involved. In addition to empirical rate-estimation procedures, we are using and developing methods to calculate reaction rates from first principles, using quantum mechanics and transition state theory. These theoretical methods are already competitive with some experimental techniques, and we are exploring ways to further improve the accuracy of these calculations. For example, we have recently developed a systematic technique for improving the accuracy of density functional calculations. We are also interested in exploring new methods to couple these detailed chemical reaction schemes with flow; the ultimate goal is to quantitatively model the multicomponent reacting flows found in real systems.
The true test of any model is how well it agrees with experiment. We are collaborating with several experimentalists in areas such as combustion, atmospheric chemistry, and the stability of engine oils. In addition to measurements made on the whole system, we plan to measure critical reaction rates individually using high precision techniques such as laser flash photolysis.
Rate-Based Construction of Kinetic Models for Complex Systems, Journal of Physical Chemistry A 101, 3731-40 (1997), (with R.G. Susnow, A.M. Dean, P.K. Peczak, and L.J. Broadbelt).
Exchange-Correlation Functionals from Ab Initio Electron Densities, Chemical Physics Letters 273, 183-194 (1997), (with D.J. Tozer and N.C. Handy).
Dramatic Solvent Effects on the Absolute Rate Constants for Abstraction of the Hydroxylic Hydrogen Atom from tert-Butyl Hydroperoxide and Phenol by the Cumyl Radical. The Role of Hydrogen Bonding, J. Am. Chem. Soc. 117, 2929-30 (1995), (with D.V. Avila, K.U. Ingold, J. Lusztyk, and D.R. Procopio).
Predictive Chemical Kinetics: Density-Functional and Hartree-Fock Calculations on Free Radical Reaction Transition States, Intl. J. Quantum Chem. 52, 837-47 (1994).
Unimolecular Reaction Rates and Transition States, Annual Review of Physical Chemistry 43, 591-626 (1992), (with C.B. Moore and W.F. Polik).
Bond-Breaking without Barriers II: Vibrationally Excited Products, Journal of Chemical Physics 94, 1961 (1991), (with A.J. Mahoney, Q.-K. Zheng, and C.B. Moore).
Theoretical Assignment of the Visible Spectrum of Singlet Methylene, Journal of Chemical Physics 94, 118 (1991), (with N.C. Handy, P.J. Knowles, and S. Carter).