Yuan T. Lee and Molecular Beam Studies
Yuan Tseh Lee 'received the 1986 Nobel Prize in Chemistry, … for elucidating the collision dynamics of elementary chemical reactions. During a postdoctoral appointment at Harvard with [Dudley R.] Herschbach, Lee designed and built a technologically advanced "universal" machine with electron bombardment ionizer and mass spectrometer detector that moved the field of molecular beam kinetics into a new era in the study of reaction dynamics. Subsequent improvements set the standard for molecular beam instrumentation, and his laboratory rapidly became a mecca for studies of collision processes. Later, lasers and molecular beams were combined to understand various primary photochemical processes and the spectroscopy of ionic and molecular clusters.
Lee was born in Hsinchu, Taiwan, China and as a youth experienced the adversity of WWII and Japanese occupation. At the war's end he resumed formal schooling and received a B.S. from National Taiwan University (1959) and M.S. from Tsinghua University (1961). He then came to the U.S. and took his Ph.D. with Bruce Mahan at the University of California, Berkeley (1965). After the postdoctoral year with Herschbach he joined the University of Chicago faculty (1968). In 1974 he moved to the University of California, Berkeley, ... [as a] Graduate Professor.'1 He became an American citizen the same year.
'In the 1980s, Berkeley Lab chemist Yuan T. Lee attempted to understand what occurs during a chemical reaction at the atomic scale. Lee and colleagues sought to examine the forces operating between atoms and molecules during chemical reactions in order to find out exactly how, and at what rate, these reactions take place.
To follow the motion of atoms and molecules as they collide and react to form new products and to observe the flow of energy between them, Lee used a technique called "crossed molecular beams." Two beams of selected molecules were accelerated at supersonic speeds, then sent on a collision course in a vacuum. When the beams hit, the angles at which the resulting products are scattered and the amount of energy released during the collision are recorded. By controlling the content and velocity of the beams, and the angle at which they approach one another, Lee and his research team were able, in essence, to "view" chemical reactions as they occur.2
2Edited excerpt from Nobel Prize Awarded to Nine Berkeley Lab Scientists, about a third of the way down the page
Additional information about Yuan T. Lee and molecular beam studies is available in electronic documents and on the Web.
Crossed Molecular Beam Studies and Dynamics of Decomposition of Chemically Activated Radicals, DOE Technical Report, 1973
Development of a Supersonic Atomic Oxygen Nozzle Beam Source for Crossed Beam Scattering Experiments, DOE Technical Report, 1978
Reaction Mechanism of Oxygen Atoms with Unsaturated Hydrocarbons by the Crossed-Molecular-Beams Method, DOE Technical Report, 1982
Molecular-beam Studies of Primary Photochemical Processes, DOE Technical Report, 1982
Molecular Beam Studies of Hot Atom Chemical Reactions: Reactive Scattering of Energetic Deuterium Atoms, DOE Technical Report, 1989
Additional Web Pages:
Infrared Studies of Ionic Clusters: The Influence of Yuan T. Lee,
Journal of Chemical Physics, Volume 125, Issue 13, pp. 132302-132302-19 (2006)