Ferrocenyl-Substituted (η5-Hydroxyalkylcyclohexadienyl)tricarbonylmanganese Complexes: Synthesis, Structural Determinations, and Formation of Carbenium Ions

Ferrocenyl-substituted (η5-hydroxyalkylcyclohexadienyl)­tricarbonylmanganese complexes have been synthesized as well as the corresponding carbenium dinuclear complexes after dehydroxylation. Studies in solution and in the solid state of these zwitterionic species show not only the electronic influence of the positive charge on the η5-Mn complex but also the participation of the two metal atoms in the stabilization of this charge. Catalytic tests show a high activity of these cations as Lewis acids in a typical Diels–Alder reaction.