The Department of Chemistry invites you to its departmental seminar today at 4:10 p.m. in Fulmer Hall, room 201. Dr. Ken Caulton from Indiana University will present, On the Road to Unsaturated “-ate” Pincer Complexes of Divalent 3d Transition Metals.
Abstract: The pincer ligand bispyrazolyl pyridine,H2L, offers potential of redox activity coupled with proton responsive character at the pyrazole beta nitrogen. If proton sensitivity is not desired, then alkylation of those positions yields a useful control for when proton delivery to substrate is to be avoided. Two general points discovered in the chemistry of this ligand are the persistence of halide ligand during attempted dehydrochlorination of cobalt and iron (H2L)MCl2 species, targeting unsaturated pincer species LM (above), and also the strong tendency of deprotonated beta nitrogen to bridge to a second metal, yielding dimetal species. The stoichiometric and catalytic reactivity of the latter in oxygen atom transfer chemistry will be discussed. A chromium analog (below) illustrates very different structural principles, combining four reducing equivalents in one molecule.
