BA (1956) Rice University
PhD (1959) Rice Univ.
Chemical dynamics, spectroscopy, lasers, theoretical chemistry
Office: Space Science 102
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James L. Kinsey
D. R. Bullard-Welch Foundation Professor of Science
Dr. Kinsey's research deals with the dynamics of the decomposition of single molecules that have been photoexcited to an unstable electronic state. In every elementary chemical reaction, the molecular system passes through a continuously evolving intermediate species that is neither reactant nor product, but the former turning into the latter. A great deal of chemical research centers on learning as much as possible about these "transition states" whose details control the reactant -- product conversion.
It has often been pointed out that the separation of the fragments produced in a photodissociation is essentially a "half collision" or "half reaction." Our work on photoemission during photodissociation gives a spectroscopic means of following the motion of the transient state leading to photochemical fragmentation. This is accomplished by recording the spectrum of light emitted by the excited molecule. Because typical times for photodissociation (~10-14 sec) are much shorter than typical radiative life times (~10-8 sec), dissociation is a powerful quenching mechanism for fluorescence. There is a tiny but finite photon yield, however, and the spectral characteristics of this radiation are extraordinarily informative about dynamic processes in the excited electronic state and in the ground electronic state as well.
In the process of coming apart, the molecule sweeps through infinite displacements in molecular geometry, thus developing the ability to radiate into extremely high vibrational levels of the electronic ground state. The pattern of intensities in these lines is a "footprint" of the dissociation process. We have investigated the photoemission/photodissociation spectra of O3, CH3I and several other molecules. Each of these molecules has provided surprising new insights, and much work remains to be done before they are fully understood. Many other molecules, with special properties that probe specific aspects of photodissociation dynamics are planned for future studies. Theoretical investigations of dynamics on experimentally characterized potential energy surfaces are also planned.
James L. Kinsey and Bruce R. Johnson "Angular Distributions
of Products in the Photodissociation of Diatomic Molecules." Journal
of Physical Chemistry A, 102 (1998): 9660-9665.
"Breaking of Chemical Bonds: Shedding Light on Dissociation." Jeremy Musher Memorial Lecture, The Hebrew University of Jerusalem. (March 11, 1998)
Jeffrey Mackey, Doctoral. "The Resonance Raman
Spectrum of Nitrosyl Chloride in the A Band." (2000).
Grants and Proposals