Controlled molecular design and polymerization of polyaromatic ethers

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Rolland de Denus, Christine Marie
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This is the first study where the number of Fe$\sp{+}$Cp moieties pendant to the backbone of polyaromatic materials could be controlled in a manner such that materials with 2-35 metal moieties were prepared. The efficiency of the presented methodological approach enabled the control of both the size and nature of the backbone linkage of these materials. A further extension of the presented synthetic approach was illustrated by the successful introduction of the Ru$\sp{+}$Cp$\sp*$ moiety which allowed for the preparation of a variety of homo-Ru$\sp{+}$Cp$\sp*$ complexes and the first heterometallic Fe$\sp{+}$Cp-Ru$\sp{+}$Cp$\sp*$ complexes to date. Electrochemical investigations of some of these oligomeric ether complexes indicated that the iron centers behaved as isolated redox centers. The rate of the following hemical reaction (k$\sb{\rm f})$ was calculated for a sampling of these materials, and it was found that the rate was affected by the nature of the solvent, the bridging ligand and the temperature.For oligomeric complexes which were capped by 1-naphthol, it was possible to liberate the organic monomers using photolysis. These monomers were subsequently polymerized under Scholl reaction conditions. Overall, it was found that the monomer structure, amount of catalyst, and solution concentration affected the molecular weight of the resultant polyether. As well, the facile preparation of macrocyclic ethers was achieved via stepwise S$\sb{\rm N}$Ar reactions with a variety of dinucleophiles. It was possible to prepare both symmetric and asymmetric systems due to the ability to isolate the intermediate bimetallic complexes prior to ring closure. Unequivocal proof for one of these materials was obtained by an X-ray crystallographic study.