In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Bradforth will perform research on the chemical reaction dynamics in liquid solutions by means of femtosecond ultra violet pump-probe spectroscopy over the wavelength range from 215 to 300 nanometers. The objective is to characterize how solvents modify and control the reactivity of embedded small molecule solutes by dynamical effects such as caging and energy dissipation. The project consists of several tasks, including 1) development of benchmark information on the electronic spectra and reorientation dynamics of equilibrated radicals such as CN, I, and I*; 2) the investigation of solute vibrational coherences initiated by electron ejection via the charge-transfer-to-solvent detachment of the doubly-charged copper bromide anion and related copper systems; and 3) photodissociation studies of ICN and BrCN to explore the nature of bond breaking and thus how the large rotational energy release of the fragments is initially dissipated. The proposed work is directed toward the larger goal of testing fundamental theories of solution kinetics, and providing a molecular picture for reactions in complex media. This research will be conducted with students and postdoctoral research associates.
