Polythiophene with pendant ferrocene groups

Polypyrroles and polythiophenes with pendant ferrocene groups (e.g., 23) have also been prepared using electropolymerization techniques.Studies of these materials using in situ conductivity measurements revealed that the redox conduction, due to hole hopping between the ferrocene units, was enhanced by a decrease of the Fc-backbone distance and by conjugation of the organometallic group with the polymer backbone (as in polymer 23 which possesses a redox conductivity of ca. 8 x 10 Scm ). 

Polythiophenes, 3-substituted by bipyridyl [268], benzoquinone [269], viologen [270], ferrocene [271], and tetrathiafulvalene [272], have been reported. The redox group is generally apparent in the voltammetric response of the polymers obtained, while the response of the polyconjugated chain is not, an indication of degradation of the backbone. Polymers of better quality with ferrocene and viologen pendants were later electrodeposited from bi- and terthiophenes [273]. 

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