Synthesis and properties of a soluble and widely conjugated polyacetylene with anthryl pendant

Abstract

The metathesis polymerization of an anthrylacetylene bearing an alkyl ester group, 9-(10-hexoxycarbonyl)anthrylacetylene (1), was conducted with various transition-metal catalysts. A completely soluble black polymer was obtained from 1 in a good yield when W-based catalysts were employed. The polymerization at a high monomer concentration (1 M) and a high temperature (80 °C) led to the formation of poly(1) with a weight-average molecular weight of 297 × 103 in an 80% yield. The use of cocatalysts unexpectedly decreased both the yield and molecular weight of poly(1). Rh-catalyzed and Mo-catalyzed polymerizations, however, resulted in poor yields of the polymer. The ultraviolet–visible spectrum of poly(1) showed a significantly redshifted absorption (λmax = 571) with a cutoff at 780 nm, which verified the very high order of conjugation of the main chain. Poly(1) exhibited the largest third-order nonlinear optical susceptibility [χ(3) (−ω; ω, 0, 0) = − 1.9 × 10−10 esu] among the polymers from the monosubstituted polyacetylenes synthesized so far. The electrical conductivity of poly(1) in an I2-doped state was 8.77 × 10−4 at 293 K. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4717–4723, 2000