Organometallics ferrocene, polymeric systems

Redox polymer — Redox polymers contain electrostatically and spatially localized redox sites, which can be oxidized or reduced. The redox polymers can be divided into subclasses 1) polymers that contain covalently attached redox sites, either built in the chain or as a pendant group. The redox centers may be organic molecules (e.g., tetrathiafulvalene, tetra-cyanoquinodimethane), organometallic molecules (e.g., - ferrocene), or co or dinative ly attached redox couples (e.g., polymerized metal bipyridine(bpy) complexes) 2) ion-exchange polymeric systems, where the redox-active ions are held by electrostatic binding (e.g., Fe(CN)g- 4- in protonated poly(vinylpiridine) or Ru(bpy)j+/2+ in -> Nafion [i]. 

Ferrocene was the starting point for organometallic chemistry nearly four decades ago and is still today one of the most studied and versatile organometallic building blocks. Ferrocene has been incorporated in polymeric systems to alter bulk properties of the material. Ferrocene possesses excellent thermal and photochemical stability and can also protect polymeric systems from photodegradation. In addition, the ferrocene building block has been used in conducting polymers and in main chain liquid crystalline polyesters. ... 

In the 1970 s Kaminsky, Sinn, and others discovered that bis(cyclo-pentadienyl)dimethyltitanium when mixed with trimethyl aluminum and water provided a catalyst system capable of polymerizing ethylene [5]. The titanium structure bears some resemblance to that of ferrocene. Ferrocene was reported in 1951 [6,7] and the following year, the correct structure reported [8]. A brief, interesting account of the early days of the research on the structure proof of ferrocene has been written [9]. Because the Kaminsky catalysts have the same sandwich structure of ferrocene, they are referred to as metallocene catalysts. Just as the ferrocene ushered in a new era of organometallic chemistry, the Kaminsky metallocene spurred a tremendous amount of research in olefin polymerization catalysts. 

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