Neutral and cationic macromolecules based on iron sandwich complexes.

This article is one of a number of reviews in the special issue of the Journal of Inorganic and Organometallic Polymers and Materials, celebrating the 50th anniversary of the discovery of metallocene-based polymers. Since the first examples of polyferrocenes in 1955, research into the design of organometallic polymers has grown exponentially. Organoiron polymers have incorporated ferrocene and arene cyclopentadienyl complexes, and have been developed for materials, liquid crystals, and electrocatalysts. The focus of this review is on the synthesis, properties, and characterization of macromolecules based on ferrocene or arene cyclopentadienyliron cations. Ferrocene-based polymers in which the ferrocene moieties are in or pendent to the backbone are described, as well as, the use of arene cyclopentadienyliron complexes in the design of polymeric materials. The design of star-shaped macromolecules and dendrimer materials that contain ferrocene and/or arene cyclopentadienyliron units will be discussed as well.