Michael Morse of the University of Utah is supported by the Experimental Physical Chemistry Program to continue his investigations on the chemical bonding and electronic structure of diatomic transition metal molecules using electronic spectroscopy. The methods to be employed include resonant two-photon ionization spectroscopy, laser-induced and dispersed fluorescence spectroscopies, and resonant two-photon pulsed field ionization zero electron kinetic energy photoelectron spectroscopy. In all cases, the sample will be generated by pulsed laser ablation of the appropriate metal target, followed by supersonic expansion. The expansion reduces the complexity of the spectra associated with the open d subshell systems, facilitating interpretation of the spectra. Research will focus on the transition metal silicides, homo- and heteronuclear transition metal diatomics, and on diatomic platinum. In the latter case, a detailed comparison to ab initio quantum chemistry will provide an important test for relativistic theories of chemical bonding. These studies will greatly enhance our understanding of the chemical bonding between transition metals and will provide important tests for the development of theoretical methods applicable to transition metal systems. For example, very little is known about the transition metal silicon bond, despite the wide use of transition metal silicides in microelectronic devices, solar cells, infrared detectors and as protective coatings.
