Polyaromatic ethers and thioethers coordinated to cyclopentadienyliron complexes

This research is focussed on the synthesis of polyaromatic ethers and thioethers using chloroarene complexes of cyclopentadienyliron. The first goal of this work was to establish that dichloroarene complexes could undergo nucleophilic aromatic substitution reactions with oxygen- and sulfur-based dinucleophiles to produce linear polyaromatic ethers and thioethers. These organometallic polymers were photolyzed, which allowed for the isolation of the corresponding organic polymers. A further examination of the reaction of trifunctional reagents with chloroarene complexes resulted in the production of star-shaped polyaromatic ethers. Polymers with ferrocenyl groups in their backbones and cyclopentadienyliron cations pendent to their backbones were prepared, and upon photolysis, ferrocene-based polymers were isolated. Reaction of chloroarene complexes functionalized with azobenzene groups with dinucleophiles allowed for the formation of highly colored polyaromatic ethers and thioethers. An investigation into the radical polymerization of methacrylate- and styrene-functionalized complexes of cyclopentadienyliron was undertaken. Polyaromatic ethers and thioethers containing methacrylate and styrene units in their side chains could also be isolated and the pendent olefinic groups were subsequently polymerized using a radical initiator to yield insoluble cross-linked polymers. It was concluded that η6-arene-η5-cyclopentadienyliron complexes are excellent precursors to aromatic polymers, and that these metallated polymers exhibit enhanced solubility compared to their organic analogues. The polymers displayed good thermal stability, and their glass transition temperatures were enhanced by the presence of the pendent cyclopentadienyliron cations. Electrochemical studies revealed that the iron centers in these polymers undergo reversible reduction processes.