This research, part of the Experimental Physical Chemistry Program, will entail spectroscopic studies of small metal and semiconductor molecules, and reactivity studies of metal clusters as functions of size and composition. These studies will contribute towards the development of a unified theory of metal/semiconductor electronic structure which can account for the variation in physical and chemical properties with size. Clusters will be prepared by laser vaporization of a target material in the throat of a pulsed supersonic nozzle, and will be detected in a vacuum chamber by photoionization time-of-flight spectrometry. Measurements of the depletion of bare metal clusters and growth of products then provide chemical reactivity rates for metal clusters as functions of size and composition. Two-photon ionization, laser induced fluorescence, and stimulated emission spectroscopies will be employed to measure bond lenghts, vibrational frequencies, and term symbols of various metal and semiconductor dimers and trimers.
