Facile synthesis and polymerization of 2,6-Difluoro-2′- sulfobenzophenone for aromatic proton conducting ionomers with pendant sulfobenzoyl groups

Abstract

The lithium salt of 2,6-difluoro-2′-sulfobenzophenone was conveniently synthesized in onepot by reacting 2,6-difluorophenyllithium with 2-sulfobenzoic acid cyclic anhydride in THF at -70°C whereafter the product crystallized out of solution. A poly(arylene ether) and a poly(arylene sulfide) were prepared by polycondensation reactions to demonstrate the reactivity and efficacy of this new monomer to produce sulfonated high-molecular weight aromatic polymers for fuel cell proton-exchange membranes. This work demonstrated that organolithium chemistry may offer versatile and straightforward pathways to new functional monomers with fluorine atoms activated for nucleophilic aromatic substitution reactions. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.