A new methodol. is described for the synthesis of poly(p-phenylenebutadiynylene)s based on the Pd/Cu-catalyzed, benzoquinone-mediated homocoupling of terminal acetylenes. Homopolymers synthesized from the 2,5-dialkoxy-1,4-diethynylbenzene monomers 1,4-bis(decyloxy)-2,5-diethynylbenzene and 1,4-bis(hexadecyloxy)-2,5-diethynylbenzene were largely insol., with the sol. portion from the polymn. of 1,4-bis(hexadecyloxy)-2,5-diethynylbenzene exhibiting a no.-av. mol. wt. of 14,000. Completely sol. polymers were obtained from these precursors by the random copolymn. of these monomers. The materials exhibited no.-av. mol. wts. ranging from 67,000 to over 150,000. The UV-visible and emission spectra of these polymers were examd. and found to be very similar to those of structurally analogous poly(p-phenyleneethynylene)s and smaller poly(p-phenylenebutadiynylene)s reported by Kijima et al. [on SciFinder(R)]