Chiral [1]Ferrocenophanes: Syntheses, Reaction Mechanisms, and Metallopolymers

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The development of organic polymers has clearly played a crucial role in the progress of our modern day life. Their applications range from shopping bags and flooring, to airplane components and electronic devices. However, as early as the 1950s scientists were intrigued by the idea to incorporate metals into polymers. After the first steps into this new field of science, it took more than four decades to overcome challenging problems. Over the last 25 years, the area of metal-containing polymers (metallopolymers) has witnessed tremendous progress; it is expected that these types of materials will be incorporated in devices in the decades to come. Despite the impressive progress, new monomers and polymerization methods are needed so that the enormous potential that the periodic table of elements offers for metallopolymers can be realized in the future. Our research program is in the area of synthetic organometallic chemistry, where we develop new metal-containing monomers and explore their polymerization behaviour. We apply ring-opening polymerization of strained sandwich species as an effective method to produce metallopolymers. The long-term objectives of the research program are: (i) to improve our fundamental knowledge about ring-opening polymerization of strained sandwich compounds, and (ii) to increase the scope of this method. In 2013 we published, and have since employed, a multistep synthesis that gives access to chiral, strained ferrocene derivatives ([1]ferrocenophanes). Because of their built-in chirality, these enantiopure [1]ferrocenophanes are a family of unique monomers. The properties of polymers are strongly dependent on their molecular weight and dispersity, not merely on their empirical formulas. For polymers with stereogenic centers, their macromolecular tacticity also has a significant effect on their physical properties. Hence, the ability to control the structures of macromolecules translates into controlling their properties. We propose to transform enantiopure [1]ferrocenophanes into a novel class of chiral metallopolymers. It is expected that their chiral structures will give rise to properties that are otherwise inaccessible. Reaction mechanisms are key to a deeper understanding of chemical reactivity and, therefore, key to a deeper understanding of chemistry in general. Even though the process of thermal ring-opening polymerization has been known for 25 years, its mechanism is still a mystery. We will use the chirality of our monomers to provide insight into the reaction mechanism of thermal ring-opening polymerization. Furthermore, we propose to expand the scope of these types of polymerizations by the development of a new polymerization process and by the synthesis of new monomers. In addition to the potential application of new materials, our program is an ideal training ground for HQP who will contribute to the Canadian economy in the future.