Erin K. Todd

Novel approach to oligomers and polymers containing neutral and cationic iron moieties within and pendent to their backbones

Polymers containing neutral and cationic iron moieties within and pendent to their backbones were prepared. The redox properties of the neutral and cationic iron centers were examined using cyclic voltammetry. Photolysis of the organometallic polymers led to decoordination of the cationic cyclopentadienyliron moieties from the polymer backbones. Glass transition temperatures of the resulting ferrocene-based polymers were lower than those of the mixed neutral/cationic polymers.

Star-Shaped Polyaromatic Ethers Coordinated to Redox-Active Cyclopentadienyliron Moieties

This communication is focused on the controlled design of star-shaped aromatic ethers with pendent cyclopentadiencyliron moieties. A trimetallic core was prepared, which was then reacted with a number of oligomeric ether complexes to give star-shaped polymers with six, nine, twelve and fifteen pendent cationic cyclopentadienyliron moieties. Cyclic voltammetric studies showed reduction of the iron centers between -0.99 and -1.41 V. Thermogravimetric analysis showed that loss of the metallic moieties occurred between 225 and 284°C.

Synthesis and Characterization of Novel Organoiron Polymers

Synthesis of novel organoiron polymers containing oxygen, sulfur, and/or nitrogen bridges was achieved via nucleophilic aromatic substitution polymerization of cyclopentadienyliron complexes of chloroarenes with a number of aliphatic and aromatic dinucleophiles.

Synthesis of Oligomeric and Polymeric Ethers Containing the Cp*Ru+ and CpFe+ Metal Moieties

A variety of homometallic (Cp*Ru+) and heterometallic (CpFe+–Cp*Ru+) oligomers with one to five metal moieties were prepared in high yields (74–90%) via nucleophilic aromatic substitution reactions. For the mixed metal systems, it is shown that the arrangement of the metal moieties along the backbone can be controlled. In addition, the synthesis of heterometallic polymers is described, along with their decomplexation and thermal properties. It was found that the thermal properties and solubility of the systems are greatly dependent on the linkages within the polymer backbone.

Polymerization of Methacrylates Containing Cationic Cyclopentadienyliron Moieties

A novel approach to the synthesis of polymethacrylates containing cationic cyclopentadienyliron moieties pendent to their side chains was accomplished via the use of π-coordinated organoiron complexes. The complexed methacrylates were polymerized in the presence of AIBN to give soluble organoiron polymethacrylates (6a and 6b, 10, 14a and 14b) in 80–90% yields. Photolytic demetallation of the organoiron polymers allowed for the isolation of their organic analogues (7a and 7b, 11, 15a and 15b) whose weight average molecular weights ranged from 48,500 to 68,300.

Organoiron Polyelectrolytes: Synthesis and Characterization of Cationic Cyclopentadienyliron Complexes of Polyarylether-Imines

The synthesis of an aromatic ether complex of cyclopentadienyliron containing two terminal aldehyde groups was achieved via metal-mediated nucleophilic aromatic substitution reactions. This dialdehyde monomer was subsequently reacted with a variety of aliphatic and aromatic diamines to produce the corresponding soluble cationic organoiron polyether-imines. These cationic organometallic polymers were characterized using IR, 1H, and 13C NMR, viscosity and thermogravimetric analysis. Viscosity measurements showed that these polymers exhibited polyelectrolyte effects in DMSO solutions. Thermogravimetric analysis showed that decoordination of the iron moieties occurred at about 300°C for polymers with aliphatic spacers in their backbones, while the cyclopentadienyliron moieties were cleaved from the polymers with aromatic spacers in their backbones at about 200°C. Photolytic demetallation of the organoiron polymers resulted in the removal of the pendent cyclopentadienyliron moieties and allowed for the isolation of their organic analogs. While the organoiron polymers were soluble in polar organic solvents, the corresponding organic polymers exhibited very limited solubilities or were insoluble. The organic polymers had glass transition temperatures between 101 and 120°C

Feature Article: Macromolecules Containing Pendent Cationic Cyclopentadienyliron Moieties

Abstract This feature article describes the synthesis of various classes of monomers and polymers incorporating organoiron moieties. Polyethers incorporating η6-substituted-arene-η5-cyclopentadienyliron moieties were synthesized via metal-mediated nucleophilic aromatic substitution reactions. Linear polymers incorporating both cationic and neutral organoiron units were prepared; these polymers underwent two electrochemical processes, oxidation of the neutral iron species occurred between 0.89 and 1.0 V and reduction of the cationic iron groups occurred between −1.10 and −1.45 V. Polynorbornenes, polymethacrylates, and polystyrenes were prepared via radical and condensation polymerization of organoiron functionalized monomers. The incorporation of azo dyes into the polymers gave rise to a variety of colored materials that could be photobleached in the presence of hydrogen peroxide. The incorporation of benzothiazole-based dyes resulted in colored polymers with higher λmax values than azobenzene-based dyes....