Bisphenol A was polycondensed with 2,6-dichloro-benzonitrile, 2,6-difluoro-benzonitrile, 2,4-difluorobenzonitrile, and 3,5-difluorobenzonitrile in sulfolane. With 2,6-and 2,4-difluorobenzonitrile, quantitative conversions were achieved, and matrix-assisted laser desorption/time-of-flight mass spectra revealed a nearly quantitative formation of cyclic oligoethers and polyethers. Furthermore, O,O'-bistrimethylsilyl bisphenol A was polycondensed with the aforementioned dihalobenzonitriles in dry N-methylpyrrolidone (promoted by potassium carbonate). Both the temperature and time were optimized. Only with 2,6-difluorobenzonitrile were nearly quantitative conversions achieved, and this resulted in high molecular weights and high cycle contents. Size exclusion chromatography elution curves exhibited a tendency toward a bimodal character when larger fractions of cycles were present. Calibration with polystyrene standards indicated number-average molecular weights of up to 10(5) Da and weight-average molecular weights of up to 2.3 x 10(5) Da. (C) 2003 Wiley Periodicals, Inc.