Synthesis of a stable 1,2-bis(ferrocenyl)diphosphene.

The synthesis and characterization of a stable 1,2-bis(ferrocenyl)diphosphene, wherein a P=P π-bond connects two ferrocenyl units will be reported. This represents an unprecedented example for a d-π electron system containing a heavier pnictogen π-spacer group. Stabilization of the highly reactive P=P π-bond was achieved by steric protection using two bulky ferrocenyl moieties.