Abstract

I measured one-color multiphoton dissociation/ ionization (MPD/MPI) spectra for a series of arene chromium tricarbonyls (ACTs). These experiments are part of a program determine whether unimolecular bond selective photochemistry is feasible using isolated gas-phase organometallic molecules. In my operational definition, bond selective chemistry must involve means of activating a molecule so that when dissociation occurs, the weakest bond does not break first. I believe that if it is possible to induce unimolecular photo-dissociation on selected excited electronic potential surfaces, it will be possible to remove selectively different ligands from a metal atom, regardless of their relative bonding energies. If excitation can be thought of as initially localized, for bond selective chemistry to occur, the dissociation must occur on a time scale competitive with the radiationless transitions associated with intramolecular energy redistribution (IER). I focus on the relative time scales of these two processes compared with that of multiphoton absorption in isolated organometallic molecules.

© 1987 Optical Society of America