Controlled design of oligomeric ethers with pendant cyclopentadienyliron moieties

Abstract

Synthetic strategies for the design of oligomeric ethers with pendant cyclopentadienyliron moieties have been developed. A wide range of these 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-(cyclopentadienyliron) arene complexes were used as building blocks for the larger systems. The crystal stuctures of three bis(cyclopentadieny1iron) arene dications, [ (q5-C5H5) Fe(q6-C6H5) -0-XC6H,X-(q6-C,H5) Fe(q5-C5H5)I2+ (X = 0 or S) and [ (q5-C5H5) Fe(q6-C6H5) -m-OC,H,O-(q6-C,H5) Fe(q5-C5H5)I2+, have been determined by X-ray crystal structure analysis. A number of routes to the synthesis of the oligomeric species (tri-, tetra-and hexa-iron moieties) have been investigated to determine the flexibility and efficiency of the proposed strategies, and these materials have been fully characterized using spectroscopic and analytical techniques. To prove further the structures of these complexes, some of them have been prepared using different starting materials, giving the same proposed products. A series of polyiron complexes containing terminal hydroxy groups have also been prepared and used a s dinucleophiles.

Nucleophilic addition to di- and poly-iron arene complex cations

“…This versatility is valuable in the investigation of synthetic routes for the functionalization of organic and polymeric compounds. In the past few years, we have been involved in the synthesis and characterization of polyaromatic ethers with or without pendant metallic moieties (44)(45)(46)(47). In this article, we report the addition of cyanide to a number of CpFe+ polyaromatic ether complexes.…”

Synthesis of substituted norbornenes and their polymerization to polynorbornenes with flexible aliphatic side-chains

“…The use of cyclopentadienyliron (CpFe + )-mediated nucleophilic aromatic substitution (S N Ar) reactions in the synthesis of both oligomeric and polymeric materials has proven to be very successful [8][9][10][11][12] . The flexible side-chains containing terminal hydroxy groups were synthesized via monosubstitution reactions of aliphatic diols with chlorobenzene complexes (Scheme 1).…”

Organometallic Polymers of the Transition Metals

“…Photolysis of these polymers (37) resulted in cleavage of the cyclopentadienyliron cations, however, the ferrocene units in the polymer backbones remained intact. [48] It was found that the polymers with cationic cyclopentadienyliron moieties pendent to their backbones (37) possessed higher glass transition temperatures, but lower thermal stability than their ferrocene-based polymeric analogs (38).…”

“…[37][38][39] Scheme 4 illustrates the stepwise synthesis of this class of materials with as many as thirty-five pendent cyclopentadienyliron moieties. These organoiron oligomers and polymers were further functionalized through nucleophilic addition to the complexed arenes.…”