Ultrafast time-resolved studies of reactive intermediates

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

With the support of the Organic and Macromolecular Program, Professor Matthew Platz and his group plan to study the photochemistry of diazirines, diazo compounds and azides ("precursors") and the birth of carbenes and nitrene reactive intermediates. Using femtosecond time resolved UV-Vis and IR spectroscopy and computational methods they will learn which transition of the precursor molecules is pumped and which excited state of the precursor leads to fragmentation to form a reactive intermediate and nitrogen. If the pumped state and dissociative states are not the same, they will study the pathway connecting them and the time scale of the dissociative process. They will verify that rearrangement can proceed in concert with nitrogen extrusion and identify the excited state responsible for that process. They will monitor the formation of hot reactive intermediates and the structural and environmental factors that control the rate at which they transfer heat to solvent and if they rearrange as they relax. The group will learn the lifetime of singlet reactive intermediates and the factors that control their relaxation to triplet state species. The research has several broad impacts. Students are trained in classical organic chemistry as well as ultrafast spectroscopic techniques and advanced computational methods. Students will learn to work in a group that does synthetic chemistry, analytical chemistry, ultrafast spectroscopy and theory. Organic, analytical and physical chemists work together and learn from each other. Historically, the Platz Laboratory welcomes women, minority and majority high school student interns, undergraduates, graduate students, post doctoral students and visiting faculty. Students learn to work with individuals of many races, ethnicities, nationalities and educational level. Numerous graduates of the laboratory have been placed in university, college and high school positions teaching chemistry, and they are committed to continue this tradition.