Facile Synthesis and Polymerization of 2,6-Difluoro-2′-sulfobenzophenone for Aromatic Proton Conducting Ionomers with Pendant Sulfobenzoyl Groups



The lithium salt of 2,6-difluoro-2′-sulfobenzophenone was conveniently synthesized in one-pot 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.

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