The bisphenol 4,4"-dihydroxy-5'-phenyl-m-terphenyl (4), containing a 1,3,5-triphenylbenzene moiety, was synthesized from a pyrylium salt obtained by the reaction of benzaldehyde with p-methoxyacetophenone with boron trifluoride etherate as a condensing agent. Polymers were obtained from 4 by a nucleophilic displacement reaction with various activated difluoro monomers and with K2CO3 as a base. A series of new poly(arylene ether)s (8a-8f) were obtained that contained phenyl-substituted m-terphenyl segments in the polymer chain. Polymers with inherent viscosities of 0.41-0.99 dL/g were obtained in yields greater than 96%. The polymers were soluble in a variety of organic solvents, including nonpolar solvents such as toluene. Clear, transparent, and flexible films cast from CHCl3 showed high glass-transition temperatures (T-g = 198-270 degreesC) and had excellent thermal stability, as shown by temperatures of 5% weight loss greater than 500 degreesC. 4 was converted via N,N-dimethyl-O-thiocarbamate into the masked dithiol 4,4"-bis(N,N'-dimethyl-S-thiocarbamate)-5'-phenyl-m-terphenyl and was polymerized with activated difluoro compounds in the presence of a mixture of Cs2CO3 and CaCO3 as a base in diphenyl sulfone as a solvent. A series of new poly(arylene thioether)s (9a-9e) were obtained with T-g values similar to those of 8a-8e. 9a-9e were further oxidized into poly(arylene sulfone)s with T-g values 40-80 degreesC higher than those for Sa-Se and 9a-9e. These polymers also had good solubility in organic solvents. A sulfonic acid group was selectively introduced onto the pendent phenyl group of polymers 8a and 8f by reaction with chlorosulfonic acid. The polymers were soluble in dipolar aprotic solvents and formed films via casting from dimethylformamide. Polymers 8a-8f, 11a, and 11f showed blue and red fluorescence under ultraviolet-visible light with emission maxima at 380-440 nm.