Polyaromatic ethers cyclopentadienyliron cations

Polyaromatic ethers coordinated to CpFe+ moieties have also been prepared via sequential S Ar reactions of chloroarene complexes with hydroquinone (189). The electrochemical behavior of cationic aromatic ether, thioether, and sul-fone complexes of cyclopentadienyliron has been studied using cyclic voltammetry and coulometry (190). Reaction of the aromatic ether complexes with sodium cyanide resulted in the formation of neutral adducts which imder-went oxidative demetallation to give the corresponding organic aromatic nitriles (191). 

The synthesis of a water-soluhle metallodendrimer containing six cationic cyclopentadienyliron moieties was also reported (249). This dendrimer was examined as a redox catalyst for the cathodic reduction of nitrates and nitrites to ammonia. Star-shaped polyaromatic ether complexes of cyclopentadienyliron were recently reported hy Ahd-El-Aziz and co-workers (250). These complexes contained up to 15 cationic cyclopentadienyliron moieties pendent to aromatic rings in the star branches (111). Electrochemical analysis of these star polymers showed that the iron centers underwent reversible reduction processes. 

Abd-El-Aziz and coworkers have reported the synthesis of star-shaped polyaromatic ethers containing up to 15 cyclopentadienyliron cations pendent to aromatic rings. Polymer 42 is an example of a water-soluble / exa-metallic star complex. Electrochemical studies showed that reduction processes for the inner and outer iron complexes could be distinguished for the hexa- and nonametallic stars. 

Polyaromatic Ethers and Thioethers Coordinated to Cyclopentadienyliron Cations... 

Star-shaped polyaromatic ethers complexed with cyclopentadienyliron cations (92) have been prepared, in which the metallic moieties are evenly spaced throughout the length of the macromolecular branches (Scheme 24). By altering the nature of the aromatic spacers between the complexed arenes, it was possible to alter the properties of these materials. Electrochemical analysis of these polymers demonstrated that the iron centers underwent reversible reduction processes. For the hexa-metallic stars (n=l), two distinct redox couples were observed at , /2=-1.20 and-1.30 V... 

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