CONTROLLED DESIGN OF OLIGOMERIC ETHERS WITH PENDANT CYCLOPENTADIENYLIRON MOIETIES

Synthetic strategies for the design of oligomeric ethers with pendant cyclopentadienyliron moieties have been developed. A wide range of the se materials have been prepared via nucleophilic aromatic substitution reactions of a mono- or di-hydroxyaromatic nucleophiles and a variety of chloroarene complexes under mild experimental conditions. The mono - and bis- (cyclopentadienyl iron) arene complexes were used as buildi ng blacks for the larger systems. The crystal stuctures of three bis(c yclopentadienyliron) arene dications, [(eta(5)-C5H5) H5)-o-XC(6)H(4)X- (eta(6)-C6H5)Fe(eta(5)-C5H5)](2+) (X = O or S) and -C6H5)-m-OC6H4O-(et a(6)-C6H5)Fe(eta(5)-C5H5)](2+), have been determined by X-ray crystal structure analysis. A number of routes to the synthesis of the oligome ric species (tri-, tetra- and hexa-iron moieties) have been investigat ed to determine the flexility and efficiency of the bi proposed strate gies, and these materials have been fully characterized using spectros copic and analytical techniques. To prove further the structures of th ese complexes, some of them have been prepared using different startin g materials, giving the same proposed products. A series of polyiron c omplexes containing terminal hydroxy groups have also been prepared an d used as dinucleophiles. The systematic increase in the number of rin gs and iron moieties allowed full characterization by monitoring the c hanges in the NMR spectra. Furthermore, the possibility of preparing h omo- and mixed-polyaromatic ethers where the number of cyclopentadieny liron moieties varied from two to thirty-five has been demonstrated.