Tris(tetramethylethylenediamine-sodium)-9,9-bianthryl—The Salt of a π Hydrocarbon Radical Trianion with Three Na+-Cπ Contacts to One Molecular Half

Quite unexpectedly, all three electrons are taken up by the same anthryl moiety when 9,9′-bianthryl is reduced with an excess of sodium metal. Thanks to the “right” ligand/solvent mixture the first radical trianion salt (depicted on the right) could be isolated. It is a contact-ion quadruple of bianthryl in which all three Na+ counterions coordinate to the same half of the hydrocarbon molecule.