2,5-Bis(pentafluorophenyl)-1,3,4-oxadiazole (FPOx) has been prepared and successfully polymerized with hexafluorobisphenol A (6F−BPA) by means of an aromatic nucleophilic substitution reaction to produce highly fluorinated poly(arylene ether-1,3,4-oxadiazole)s (FPAEOx). The presence of the highly electron-withdrawing oxadiazole (Ox) group in FPOx significantly enhanced the reactivity of the p-fluorine substituents such that the reaction could be completed in only 1−2 h at room temperature in the presence of 4.0 equiv of potassium fluoride (KF). These mild reaction conditions with low reaction temperatures and the use of a mild base effectively prevented side reactions and ensured the formation of polymers with number-average molecular weights up to 64 000 Da free of cross-linking. FPOx itself and this unit in the FPAEOx were found to be capable of selectively binding fluoride anion (F-) with high affinity, and produced new peaks in UV and fluorescence spectra, which are in new regions and well-isolated fr...