Synthesis of Deeply Colored Soluble Polyacetylenes from 1-Ethynylnaphthalene and 3,6-Dibutyl-9-ethynylphenanthrene

Abstract
Deeply colored soluble polyacetylenes were synthesized from 1-ethynylnaphthalene and 3,6-dibutyl-9-ethynylphenanthrene by employing a tungsten (IV) catalyst. Since 2-ethynylnaphthalene gave the less conjugated polymer, connection mode of the aromatic pendants was found to be essential for maintaining the conjugated structure of the polyene chain. Electrochromic properties of poly(1-ethynylnaphthalene) were also studied.