End-functionalized poly(phenylacetylene)s were synthesized by the polymerization of phenylacetylene (PA) using the well-defined palladium catalysts represented as [(dppf)PdBr(R)] {dppf = 1,1'-bis(diphenylphosphino)ferrocene}. The Pd catalysts having a series of R groups such as o-tolyl, mesityl, C(Ph)-CPh2, C6H4-o-CH2OH, C6H4-p-CN, and C6H4-p-NO2 in conjunction with silver triflate polymerized PA to give end-functionalized poly(PA) s bearing the corresponding R groups in high yields. The results of IR and NMR spectroscopies and MALDI-TOF mass analyses proved the introduction of these R groups at one end of each polymer chain. The poly(PA) bearing a hydroxy end group was applied as a macroinitiator to the synthesis of a block copolymer composed of poly(PA) and poly(beta-propiolactone) moieties. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5549-5556, 2010