A series of eight tetraarylphosphonium polyelectrolytes (TPELs) has been successfully synthesized by polymerization of diphenylphosphine and bis(aryl triflate)s. The bis(aryl triflate)s are readily prepared from bisphenols, some of which are commodity feedstocks such as bisphenol A. The polymerization via palladium catalyzed P-C bond formation produces degrees of polymerization up to 65. All polymeric triflates have reasonable thermal stability in the range of 350-450 degrees C. The stability of the TPELs to alkaline solution is strongly depending on the spacer between adjacent phosphonium sites. Polymers with electron-releasing and bulky substituent para- to the phosphonium site have improved stability while those with electron-withdrawing substituent para- to phosphonium site have decreased alkaline stability due to decomposition via a nucleophilic aromatic substitution pathway. These findings have important ramifications for the design of ionomers for alkaline exchange membrane fuel cells and related electrochemical energy conversion devices. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1984-1990