Acquisition of a Continuous-Wave Ring Laser for Recording Electronic Spectra of Gaseous, Metal-Containing Free Radicals

Macalester College, Saint Paul MN

Investigators

Abstract

With this award from the Major Research Instrumentation (MRI) Program, the Department of Chemistry at Macalester College will acquire a continuous-wave ring laser system. This equipment will be used to measure and analyze the optical spectra of second- and third-row transition metal fluorides and oxides. The PI and his undergraduate collaborators will record laser excitation spectra at Doppler-limited resolution in order to determine the vibrational, rotational and fine-structure constants of newly observed molecules. Further work at sub-Doppler resolution utilizing the technique of intermodulated fluorescence will reveal the hyperfine structure of the observed transitions, which is useful for identifying the electronic configurations of the ground and excited states. In addition, the instrumentation will be used as a resource in advanced courses and laboratories in the Chemistry Department. Interest in understanding the complex electronic structure and spectroscopy of small, transition metal-containing molecules in the gas phase continues to grow. With the development of high-resolution and high-power tunable laser sources, spectroscopists can now record and assign spectra that previously were very difficult to acquire or analyze. Such molecules are of practical interest in fields as diverse as astronomy, catalysis, metallurgy and organometallic chemistry. Diatomic molecules containing a transition metal display the simplest form of metal bonding and are therefore relevant as initial models for more complex systems.