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Wenjin Cao will be presenting his exit seminar: Spectroscopic characterization of La-mediated hydrocarbon activation. 

Abstract: Lanthanum-mediated bond activation reactions of small hydrocarbon molecules, including alkenes, alkynes, and alkadienes, were carried out in a laser vaporization metal cluster beam source. Time-of-flight mass spectrometry and mass-analyzed threshold ionization spectroscopy, in combination with quantum chemical and multi-dimensional Franck-Condon factor calculations, were utilized to identify the reaction products and investigate their geometries, electronic structures, and formation mechanisms. The La-hydrocarbon radicals formed via dehydrogenation or C-C bond cleavage had lanthanacyclic structures in various sizes. Formations of dehydrogenated products were either through a concerted hydrogen elimination process or the dehydrogenation after ligand isomerization. The C-C bond activation proceeded through La-assisted hydrogen migration, followed by C-C bond cleavage, or vice versa.

Faculty Advisor: Dr. Dong-Sheng Yang