Macromolecules containing redox-active neutral and cationic iron complexes

Nucleophilic aromatic substitution reactions of chloroarene cyclopentadienyliron complexes were utilized to prepare new classes of oligomers and polymers containing both neutral and cationic organoiron complexes in their structures. Photolysis of these polymers resulted in the removal of the cationic cyclopentadienyliron moieties, while the neutral organoiron complexes remained intact within the polymer structures. The weight-average molecular weights of these polymers after photolysis ranged from 8700 to 56 200 with polydispersities from 1.1 to 3.1. Thermal analysis established that the cationic polymers possess higher glass transition temperatures, but lower thermal stability than the neutral ferrocene-based polymers. The glass transition temperatures of the cationic polymers ranged from 65 to 161 degrees C, while the T(g)s of the neutral polymers ranged from 10 to 92 degrees C. Electrochemical studies showed that the iron centers in the neutral complexes were oxidized, while the cationic complexes were reduced. Viscosity studies showed that the cationic polymers exhibited a polyelectrolyte effect.