Grant: Research Tools and Instruments - Category 1 (<$150,000)

Molecular ions and radicals are highly reactive intermediates at normal temperatures and pressures. Despite their short lifetimes, these entities are of great importance as they drive numerous chemical processes such as combustion of fuels, polymerization to produce plastics, formation of astronomical objects and oxidative stress in wound healing.Although molecular ions and radicals are fundamental to many chemical reactions, little is known about their structures and motions because it is difficult to produce and trap them in the laboratory on time scales suitable for detailed experimental study. This application concerns the purchase of the necessary equipment to complete the construction of a Fourier transform microwave spectrometer. Reactive species will be stabilized in a supersonic jet at low temperatures and pressures before stable products are formed. This instrument will be used to measure rotational spectra of a variety of molecular ions and radicals at the University of Manitoba. The spectra will be analyzed to obtain extremely accurate information about molecular structures and motions. These details are necessary to predict the chemical reactivity of molecular ions and radicals in other environments.At present, the microwave spectrometer is not operational as it lacks vacuum pumps to evacuate the microwave cavity. High vacuum is essential for this research as the technique relies on a supersonic jet to cool and isolate the transient molecules. Secondly, a computer control system must be implemented to operate the spectrometer. This requires the purchase of software and five computer cards. Finally, the existing microwave synthesizer was used previously for measuring spectra of neutral, closed shell species and is not suitable for probing ions and radicals. As a result, funds are requested to purchase a more powerful, versatile microwave signal generator that meets the specific needs of the proposed research program.