SYNTHESIS OF HYPERBRANCHED CONJUGATIVE POLY(ARYLENEETHYNYLENE)S BY ALKYNE POLYCYCLOTRIMERIZATION

A series of new hyperbranched poly(aryleneethynylene)s are synthesized by the copolycyclotrimerizations of tetraynes (I and II) with aliphatic monoynes (A-C) catalyzed by tantalum-, niobium-, and cobalt-based catalysts. All the reactions proceed smoothly and soluble polymers of high molecular weights (M_w up to 3.8 × 10⁴) are obtained in high yields (up to 97%).