Urano­cene

Other names: bis(η⁸-cyclo­octa­tetra­enyl)­uranium(IV), uranium cyclo­octa­tetra­enide, U(COT)₂

C₁₆H₁₆U

47/50 rare

Uranocene is the prototypical member of the actinocenes, a subclass of the metallocene family of inorganic sandwich complexes. Actinocenes are notable because they feature the coordination of radioactive actinide metals such as thorium, protactinium, uranium (as here), neptunium, or plutonium. Furthermore, these actinide ions are sufficiently large that the sandwiching organic ring is an eight-membered cyclooctatetraene dianion, COT^2-. It is necessary that this octagonal ring be a dianion, as neutral cyclooctatetraene is in fact a highly unstable antiaromatic molecule.