Metal ligand multiple bonds have long been of interest to organometallic chemists since they are often the key intermediate in catalytic oxidation reactions, such as aziridination or epoxidation. Recently, particular attention has been drawn towards oxo, imido, and nitrido complexes of late transition metals, such as iron, while early metals, such as chromium, have been overlooked. This disregard is perhaps not unwarranted, since most reported chromium complexes with metal ligand multiple bonds are high valent and have little to no reactivity. A strong σ-donor platform prepared recently by our group incorporating dianionic tetracarbenes as auxiliary ligands allows us to stabilize and isolate a highly unsaturated square planar Cr(II) tetracarbene complex.  This complex is highly reactive towards oxidants such as Me<sub>3</sub>NO and organic azides, leading to a Cr(IV) oxo and imide, respectively.  Varying the steric bulk of the azides allows us to control the reactivity between imide and tetrazene complexes. The synthesis, structure and reactivity of these novel Cr(II) and Cr(IV) tetracarbene complexes will be discussed.

Oxidative group transfer reactions on macrocyclic N-heterocyclic tetracarbene chromium complexes

253rd National Meeting (2017)

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