Actinocene
An actinocene is a type of organoactinide metallocene compound that contains an element from the actinide series. The typical structure is a sandwich compound, with two cyclooctatetraenyl dianions bound to an actinide-metal center in the oxidation state IV, with the resulting general formula An2
The most studied actinocene is uranocene, U2.
The actinide-cyclooctatetraenyl bonding was shown by computational chemistry to be mainly due to mixing of actinide 6d orbitals into ligand π-orbitals and therefore donation of electronic charge to the actinide, with a smaller such interaction involving the actinide 5f orbitals.
Other actinocenes include protactinocene, thorocene, neptunocene, and plutonocene.
Sandwiched M2 compounds exist for M = Nd, Tb, Pu, Pa, Np, Th, U and Yb.
