Loomis was one of just 24 fellows selected out of an applicant pool of approximately 100. He was nominated by both chemistry department Chair Joseph J.H. Ackerman, Ph.D., the William Greenleaf Eliot Professor, and Chancellor Mark S. Wrighton.

Richard A. Loomis, Ph.D.

The Fellowship in Science and Engineering Program, established in 1988 by the David and Lucile Packard Foundation, encourages the nation's most promising, young university professors to pursue their science and engineering research with few funding restrictions and limited paperwork requirements. The foundation hopes this program will improve scientific research by persuading exceptional scientists and engineers to remain within academia to conduct basic research and to teach the next generation of science leaders.

Every year, the foundation's Fellowship Advisory Panel invites the presidents of 50 universities to nominate two young professors from each of their institutions. The nominations, proposals, and application packets are carefully reviewed by a panel of distinguished scientists, who select the 24 fellows who exhibit the most promise for developing novel research programs that will result in a significant impact on the science and engineering communities.

Of the 24 awards this year, only four fellowships were awarded to chemists, and Loomis is the University's first in chemistry and only the fourth overall to receive this prestigious award since its inception. The other University recipients are Michael E. Wysession, Ph.D. (1992), Department of Earth and Planetary Sciences, Jonathan B. Losos, Ph.D. (1995), and Barbara N. Kunkel, Ph.D. (1997), both from the Department of Biology, and all in Arts & Sciences.

Loomis earned a doctorate in chemistry in 1995 from the University of Pennsylvania and then received a prominent National Research Council Postdoctoral Fellowship with the National Institute of Science and Technology and the University of Colorado from 1996-98. Loomis joined the Washington University Department of Chemistry as an assistant professor in fall 1998.

As a physical chemist, Loomis' research interests are centered on probing and controlling reaction dynamics at the most fundamental level, that is, with atomic resolution. Loomis recalls that these interests developed in his first high school chemistry class.

While he could comprehend that two chemicals, when mixed together in a beaker, would react forming different products when the appropriate temperature conditions were achieved, he still questioned exactly how the reaction between the molecules within the chemicals occurred. While his teachers and later his professors could make solid conjectures at the mechanisms of these reactions, the precise details --for example, the exact geometries between the reactant molecules as they approached one another, the motions induced throughout the reaction event, and the time-scales for each step of the reaction --still remained unknown to him and everyone.

What Loomis wanted was to examine closely a molecule and videotape that molecule as it approached a reaction partner, then observe the two reactants combining as an intermediate, and finally witness the intermediate evolve into product molecules. While that is seemingly impossible, Loomis' research group actually is now approaching this capability.

The experiments in the Loomis laboratory uniquely blend a combination of established molecular beam techniques that allow them to cool reactants to the lowest possible temperatures, about negative-273 degrees Celsius, with sophisticated laser technology. This in turn enables them to initiate the reactions with specific energies and preferred orientations at well-defined times.

By using multiple lasers, they can not only precisely start the reactions, but also monitor the decay of the reactants or the formation of the products using a second laser set to appropriate spectroscopic transitions. At a given delay in time between the first and second laser, a snapshot of the populations of the reactants and products, as well as the relative orientations among the atoms involved in the reaction, can be recorded at that instant along the reaction pathway.

By recording numerous snapshots at incrementally increasing delay times between the lasers, a movie of the reaction of interest is generated at the atomic level with sufficient time resolution, less than 0.0000000000001 seconds, to see geometries changing, bonds breaking, and new bonds forming.

The research program that Loomis will be developing using the grant awarded by the Packard Foundation will build on his group's current efforts and will further lead the field of chemical reaction dynamics to new directions. The proposed research will take advantage of quantum interference effects within the reactants and products to focus ensembles of molecules at particular places along the reaction pathway at a given time.

In these experiments, the Loomis group will set the region of the reaction path where they want the molecules to focus and set the properties of the second laser to monitor the molecules in that region. A computational genetic learning algorithm will be implemented to optimize the properties of the first laser (the phase and amplitude of the light) necessary to focus the molecules at that spot. Such an algorithm derives its behavior from a metaphor of the processes of evolution in nature.

Furthermore, in a similar manner, molecules can be prepared with a preferred momentum at that region along the reaction pathway. If there is a region with branches in the reaction pathway that lead to different reaction product channels ,then the fate of the reactants could be determined by optimizing the momentum of the reactants to be along a desired path at the branching point.

Initially, Loomis will use his technique of quantum control over bimolecular reactions to characterize the pathways sampled in reactions relevant to combustion, atmospheric and planetary chemistry. Funds from the fellowship will initially be used to develop the apparatus for these experiments and to support one graduate student and one postdoctoral fellow to concentrate full-time on these efforts.

Another exciting impact area in the near future is quantum computing, which employs the manipulation of the properties of elementary particles, such as the energy localized within molecules or the electronic states within atoms or molecules, using the rules of quantum mechanics. Here the learning algorithm and the first laser could be used to encode information into the well-characterized clusters comprised of chemical reactants. The second laser would be used to extract the encoded information from the system at a desired time.