Luminescent Photofragments of (1,1,1,5,5,5-Hexafluoro-2,4-pentanedionato) Metal Complexes in the Gas Phase

Article abstract of DOI:10.1021/ic971340x

The luminescence that is observed under gas phase photolytic deposition conditions is studied for Cr(hfac)₃, Ni(hfac)₂, and Pt(hfac)₂. This luminescence is analyzed under a variety of conditions, including the relatively high pressures of an evacuated gas cell and the collision-free conditions of a molecular beam. The effects of inert buffer gas are also studied. Features in these spectra indicate that, in general, multiple photolysis processes occur. Some simple fragments that are produced from these compounds are identified, including bare metal atoms (Ni, Cr), metal monofluorides (NiF, CrF), CH (in the case of Ni(hfac)₂), and metal carbide from Pt(hfac)₂. It is postulated that the difference in the observed photofragmentation pathway in the case of platinum is due to σ bonding to the β carbon of the hfac moiety as opposed to the bidentate bonding of the other two metals. Possible mechanisms are presented. Detailed analysis of the spectra allows characterization of the internal energy of the platinum carbide photofragment.