Polycondensation of Metallocenes

The polycondensation of acetylene-substituted metallocenes has yielded polymers containing backbone aUcyne bridges. The synthesis of l-iodo-2-methoxy-methyl-3-ethynylferreocene and l-iodo-2-(N,N-dimethylamino methyl)-3-ethynyl-ferreocene was reported by Plenio and coworkers. Polymerization of these ferrocene-based complexes gave rise to soluble bimodal 1,3-linked ferrocene-acetylene polymers. Polymers exhibiting optical activity or functionalized sidechains were produced via Sonogashira coupling reactions. 

Polymetallocenes with acetylene emits in their backbones have been synthesized through reactions of diiodoferrocenes with diethynyl monomers, as shown in scheme These polymers, formed through palladium-catalyzed reactions, displayed semiconducting properties upon doping with iodine. The iodine adduct of polymer 28a exhibited an electrical conductivity of 1.3 X 10 S/cm, while 28b was resistant to oxidation.  

One of the most important methods for obtaining organometallic polymers is poly condensation. In 1961 Knobloch and Rauscher reported the synthesis of polyesters and polyamides with ferrocene groups in their backbones using interfacial polymerization. 

Research in metallocene-containing polyamides, polyureas, polyuretiianes, and polyesters continued to be conducted in the 1980s, and since that time, research into these classes of materials has continued to grow7 Homoannular and heteroaimular liquid-crystalline polymetallocenes have been prepared by Zentel and coworkers through condensation reactions. Ferrocene-based liquid-crystalline polymers have also been reported by Senthil and Kannan. The synthesis of ferrocene polymers containing backbone organophosphorus moieties 32 is shown in scheme 9. 

Wright and coworkers examined the NLO properties of some mainchain ferrocene-based polymers. The polymers 33 and 34 were formed by 

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