Synthesis and Properties of Polyacetylenes Having Pendant Carbazole Groups

Five novel carbazole-containing polymers, i.e., poly(3,6-di- tert -butyl-9-prop-2-ynylcarbazole) [poly( t -Bu 2 CzPr)], poly(9-but-2-ynylcarbazole) [poly(CzBu)], poly(3,6-di- tert -butyl-9-but-2-ynylcarbazole) [poly( t -Bu 2 CzBu)], poly(9-(4-ethynylphenyl)carbazole) [poly( p -CzPA)], and poly(9-(4-prop-1-ynylphenyl)carbazole) [poly( p -CzPPr)] were synthesized by the polymerization of the corresponding carbazole-containing acetylene monomers using [(norbornadiene)RhCl] 2 −Et 3 N, WCl 6, MoCl 5, TaCl 5, and NbCl 5 in conjunction with Sn, Bi, Sb, and Si cocatalysts and W(CO) 6 − h ν/CCl 4 catalysts. The UV−vis absorption band edge wavelengths of poly( t -Bu 2 CzPr) and poly( p -CzPA) were longer than those of the corresponding polymers substituted by methyl group at the main chain, poly( t -Bu 2 CzBu) and poly( p -CzPPr), respectively. The band edge wavelengths of phenylene-spacer-containing polymers, poly( p -CzPA) and poly( p -CzPPr), were longer than those of methylene-spacer-containing polymers, poly( t -Bu 2 CzPr) and poly( t -Bu 2 CzBu), respectively. Poly( p -CzPA) obtained by WCl 6 − n -Bu 4 Sn-catalyzed polymerization exhibited UV−vis absorption apparently at a longer wavelength than the MoCl 5 − n -Bu 4 Sn-based counterpart did. Poly( t -Bu 2 CzPr) showed photoconductivity. The temperatures for 5% weight loss of the polymers were around 300−350 °C under air.