[Bis{(η⁵‐pentamethylcyclopentadienyl)cobalt}‐μ‐(η⁴:η‐arene)]: Synthesis, Structure, and Unusual Reactivity of a New Type of Triple‐Decker with Bridging Arene Ligands

Abstract

A μ-η4:η4-arene bridge was detected for the first time in the triple-deckers 1 (arene = benzene, toluene, o-, m-, p-xylene, cumene). This bridging ligand deviates substantially from planarity in the X-ray crystal structure analysis of the cumene derivative (see picture) and is already substitutionally labile at room temperature. It can be exchanged for other π-perimeter compounds without affecting the molecular structure.