Drs. Bernstein and Kelley plan a study of the time resolved photophysics and photochemistry of molecules and molecular clusters prepared and isolated in a supersonic molecular jet. The work will be centered about supersonic molecular jet spectroscopic studies of solute-solvent clusters and solute dimers and will also deal with time resolved (picosecond) spectroscopy of simple chemical reactions and intramolecular dynamics. The molecular jet produces very cold molecules and clusters isolated for easy optical spectroscopic characterization by techniques including fluorescence excitation, dispersed emission, and two-color time of flight mass spectroscopy. Cryogenic solutions are of particular spectroscopic interest for the study of the liquid state, and solution phenomena in general. Well known molecular systems can be employed as dilute spectroscopic probes of the solvent, and the low temperature of the solution allows one to obtain excellent liquid state spectroscopic resolution. It is possible to observe spectroscopically the formation of clusters, dimers, and van der Waals molecules; in essence, the preliminary stages of nucleation and precipitation processes in solution can be followed spectroscopically.
