Design of Polyaromatic Ethers Using Cyclopentadienyliron Complexes

Abstract

Nucleophilic aromatic substitution of cyclopentadienyliron complexes of chloroarenes with oxygen-containing nucleophiles led to the isolation of a number of aromatic ether complexes (2, 5a − e) in very good yields. Reactions of these complexes with 1-naphthol, followed by removal of the cyclopentadienyliron moieties produced aromatic ether compounds with terminal naphthoxy groups (3, 7a − e). Polymerization of these monomers in the presence of ferric chloride gave the poly(aryl ethers) 4 and 8a − e. These materials were obtained with weight-average molecular weights up to 139 900 g/mol. Thermogravimetric analysis of the poly(aryl ethers) showed that these materials displayed no significant weight loss until 458−575 °C. The glass transition temperatures for these polymers ranged from 147 to 226 °C, as measured by differential scanning calorimetry.

Non‐Porous Low‐k Dielectric Films Based on a New Structural Amorphous Fluoropolymer

“…The thermostability of PFN was evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), as depicted in Supporting Information ( Figure SI-1). PFN has a glass transition temperature ( T g ) of 235 o C, which is higher than those of previously reported poly(naphthyl ether)s, [ 18 ] suggesting that introducing bulky perfl uorocyclobutane units into the backbone of the polymer further retards the movement of chains in the polymer. From the DSC trace of PFN , no peaks of crystallization or fusion are observed, demonstrating the polymer was amorphous from another perspective.…”

Design of polyethers, thioethers, and amines with pendent iron moieties

“…The activating ability of group IV–VI transition‐metal carbonyls and cyclopentadienyls has been studied, and it has been established that the displacement of the chloro groups of coordinated chloroarenes increases in the following order: Cr(CO) 3 ≪ CpFe + ≈ CpRu + < Mn + (CO) 3 29–32. Nucleophilic substitution reactions of chloroarenes complexed to the cyclopentadienyliron moiety have been the focus of many studies directed toward the design of functionalized molecules 33–36. We previously reported the controlled design of oligomeric complexes of cyclopentadienyliron containing aromatic ether linkages 37.…”

“…Some of these etheric molecules were used in the synthesis of substituted norbornenes, which were polymerized via ring‐opening metathesis polymerization to give the corresponding polynorbornenes with aromatic ether side chains 33. We also reported the preparation of monomers with terminal naphthoxy groups using the electron‐withdrawing ability of the cyclopentadienyliron moiety to mediate their synthesis 35. After the removal of the metallic moieties from the monomeric units, polyaromatic ethers were prepared via the Scholl reaction.…”

(Arene)Cr(CO)3 Complexes: Aromatic Nucleophilic Substitution

“…In that case, the only addition/oxidation product is a cyclic dimer, the [3.3]-metacyclophane, (58). Reversibility again is apparent with the higher homologue (59). At low temperature (0.5 h/-78 °C), a mixture of cyclohexadienyl anionic intermediates is formed with the spiro ring isomer (60) preferred by a factor of almost 3:1.…”

“…Phenoxides undergo substitution for chloride [58][59][60]. The first substitution in a dichlorobenzene complex occurs at -20 °C [61].…”