Synthesis, structure, and ring-opening polymerisation of strained macrocyclic biaryls: a new route to high-performance materials

Abstract

A series of new, all-aromatic, macrocyclic biaryls have been obtained by intramolecular, nickel-promoted coupling of bis(4-chlorobenzoylphenoxy)-terminated oligomers, and single-crystal X-ray analysis of one such macrocycle reveals extreme distortion of the biaryl unit; these highly strained materials undergo rapid ring-opening polymerisation in the presence of nucleophilic initiators to give high molecular weight polyetherketones.

Recent Developments in Polyether Synthesis

“…Early reports of all-aromatic diarylene ether ketones and sulfone cyclomers, and their S N Ar-mediated ROP using CsF and potassium 4-benzoylphenolate appeared over a decade ago, [33] but the routes to cyclomers were low-yielding and required rather high polymerization temperatures. An interesting alternative for poly(arylene ether ketone)s was developed by Hay and coworkers [34] based on the use of 1,2-dibenzoylbenzene to promote cyclomer formation.…”

Ring-closing depolymerisation of aromatic polyethers

“…Ring-opening polymerisation of macrocyclic aromatic ether ketones and ether sulfones offers a potentially valuable route to high-performance aromatic polymers, [1][2][3] and such chemistry has recently become the focus of significant research activity. 4 Advantages of this approach, in the production of composite structures for example, include the very much lower initial viscosities of macrocyclic oligomers relative to the corresponding high molecular weight polymers, the complete absence of by-products, and the fact that ring-opening polymerisations of strain-free macrocycles are largely entropy-driven and thermally neutral.…”

Synthesis and ring‐opening polymerization of macrocyclic aromatic sulfide oligomers

“…Using macrocyclic oligomers as intermediate to prepare high‐performance polymers via ring‐opening polymerization (ROP) is a hot study area nowadays 9–17. For the synthesis of cyclic oligomers, stepwise preparation of well‐defined monodisperse cycles have been reported 18, 19.…”