On the Way to Ligating Oligocyclopentadienyls: Synthesis and Preliminary Reactions of the Two Isomeric Tercyclopentadienyls and Their Transition Metal Complexes

Homo- and heterotrinuclear transition-metal complexes of the two tercyclopentadienyl isomers have now become accessible via a generalizable synthetic strategy. The tricyclic ligands are prepared by coupling the fulvalene dianion with 3-chloro-2-cyclopentenone. Such transition-metal complexes—with or without M-M bonds—permit intramolecular transfer of the ligands L between the various metal atoms.