Chemistry Guest Seminar

“Ligand-based Reactivity of Metal Dithiolenes: Production of Chiral Ligands, Activation of Sulfur Heterocycles, and other New Stoichiometric and Catalytic Reactions”

Ligand-based reactivity (“non-innnocence of ligands”) made its first appearance decades ago, when redox chemistry was observed that was based at the ligand of a metal complex and not at the metal center. In recent years it became clear that ligand-based reactivity is a powerful strategy for the formation of carbon-heteroatom bonds. We observe such reactivity for metal dithiolene complexes, in particular when the reactivity of the ligand is properly tuned by the choice of a “spectator metal”. We have studied a variety of dithiolene complexes, using nickel, molybdenum and platinum. Such systems bind alkenes and/or dienes at the sulfur centers of the ligand. We have produced chiral ligands by this method and have also developed a catalytic cycle for dihydrobenzodithiin production by means of activation of bis-o-phenylene tetrasulfide. In addition, labile sites at the metal can be generated, utilized in new reactions that active small sulfur-containing molecules. First results will be discussed regarding modeling of industrial hydrodesulfurization catalysts with such compounds.