A series of new pi-conjugated poly(aryleneethynylene)s containing a 1,3,5-triazine unit in the main chain were synthesized in yields higher than 70% by poly-condensation between dibromophenyl-1,3,5-triazine monomers and alkyl-substituted diethynylbenzene (or diethynylfluorene) comonomers with Pd(PPh3)(4) and CuI as catalysts in the presence of triethylamine. The polymers had a number-average molecular weight in the range of 5000-10,000 and showed good solubility in common organic solvents. The polymers were photolumineseent both in solutions and in the solid state. X-ray diffraction patterns of the powders of the polymers revealed that the polymers were semicrystalline. Electrochemically, the polymers appeared to be reversible under reduction. (c) 2006 Wiley Periodicals, Inc.