Mark SmithProfessor Emeritus
Building: OC 221B
Education and Appointments
|Chemical Physics/Reaction Dynamics/Laser Spectroscopy/Atmospheric Chemistry/Interstellar Chemistry|
One area of our research program is centered about the study of molecular collision dynamics in the gas phase. A large part of the work, both experimental and theoretical, is associated with the development of new radiofrequency ion traps for low temperature kinetic measurement. These techniques now allow the study of gas phase ion-molecule and soon, ion-radical reactions from 300 K down to temperatures below 10 K. The results are providing critical insight into reaction mechanisms and find direct application to the study of chemical evolution in interstellar media and terrestrial and planetary atmospheres. Experimental studies have focused on the chemical reaction mechanisms in anturally low temperature environment such as interstellar molecular clouds and circumstellar shells.
A separate direction for our group has involved the study of the organic chemistry of Saturn's large moon, Titan. Ion and photochemistry in the dense upper atomosphere of this object produces large quantities of organic aerosols, dubbed tholins. These tholins fall to the 100K surface and providing the organic feedstock for subsequent hydrolysis or oxidation chemistry. The development of this chemistry , its potential role in prebiological processes on Titan are of particular interest. The work in our group involves laboratory generation of tholin analogues, extreme ultraviolet photochemistry of Tian's ionosphere, production of organic aerosol haze in its atmosphere and the determination of physical characteristics and chemical reactivity of this complex material. This work is in collaboration with scientists at the UA Planetary Science Department, Caltech and the Jet Propulsion Laboratory.