The photo-induced dissociative ionization of lanthanide ligand complexes Ln(hfac)3 (Ln = Pr, Er, Yb) was studied using the intense sub-30fs, 800nm laser pulses with time-of-flight (TOF) mass spectrometry. Under the radiation of transform limited (TL) pulse, various Fluorine and Ln contained high mass fragments, including the molecular parent ion, were observed, which were not reported in previous studies with ns or CW lasers. These observations provide insightful clues in deducing the photo-fragmentation pathways and to understand the mechanisms of fluorine-contained photofragment formations. We also applied pulse shaping technique and carried out closed-loop feedback control experiments to identify shaped pulses that optimize the ratio of LnF+/LnO+. The results showed that, the formation of LnF+, which involves the metal-ligand bond-breaking followed by bond rotation and bond rearrangement, favors long pulse duration, in consistent with the previous studies, where very little LnO+ were observed. We further applied a recently developed experimental on-line analysis tool, named control pulse slicing (CPS), to elucidate the dynamics of the control mechanisms with distinct pulses that respectively maximize and minimize the ratio of LnF+/LnO+.

Controlling the fluorine-contained photofragments formation in Ln(hfac)3 with fs laser dissociative ionization

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.