Transition metal oxo complexes, particularly those of later transition metals, have been cited as important intermediates in processes such as C-H hydroxylation and oxygen evolution. In general, however, these species are highly reactive and difficult to isolate and study. In this talk I will present our laboratories efforts at isolating and studying late transition metal oxo complexes. We have found that use of pseudo-tetrahedral geometries enables the isolation of an unusual terminal Co-oxo complex. The reactivity of this species towards C-H activation is markedly different than that observed for the majority of other systems and provides experimental evidence for a new mechanistic scenario dubbed "asynchronous" CPET. Finally, the possible relevance of related Co and Ni complexes in this system towards O-O bond formation will be discussed.
John Anderson (University of Chicago)