Abstract: | Polymerizations of 1‐naphthylacetylene (1‐NA) and 9‐anthrylacetylene (9‐AA) by various transition metal catalysts were studied, and properties of the polymers were clarified. 1‐NA polymerized with WCl6‐based catalysts to offer dark purple polymers in good yield. Especially, a binary catalyst composed of WCl6 and Ph3Bi gave a polymer with high molecular weight (Mw = 140×103) and sufficient solubility in common solvents. The use of Mo and Rh catalysts, in contrast, resulted in the formation of insoluble red poly(1‐NA)s. 9‐AA gave insoluble polymers by both WCl6‐ and MoCl5‐based catalysts in moderate to good yields. Copolymerization of 9‐AA with 1‐NA by WCl6–Ph3Bi provided a soluble copolymer which exhibited the largest third‐order nonlinear optical susceptibilities (χ(3)(−3ω; ω, ω, ω) = 40×10−12) among all the substituted polyacetylenes synthesized so far. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 277–282, 1999 |