Synthesis and Properties of Helical Polyacetylenes Carrying Cholesteryl Moieties

✍ Scribed by Jinqing Qu; Masashi Shiotsuki; Fumio Sanda; Toshio Masuda

• Book ID: 102939266
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 544 KB
• Volume: 208
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200600601

✦ Synopsis

Abstract

Novel acetylene monomers containing cholesteryl groups, N‐cholesteryloxycarbonyl‐2‐ethynylcarbazole (1) and cholesteryl N‐propargylcarbamate (2) were synthesized and polymerized with an Rh catalyst to give the corresponding polymers [poly(1) and poly(2)] with $\overline M _{\rm n} $ of 22 600 and 26 600 in 56% and 95% yields, respectively. CD spectroscopic studies revealed that poly(1) and poly(2) took predominantly one‐handed helical structure in CHCl~3~, THF, and toluene. The helical structure of poly(1) remarkably changed upon temperature, while that of poly(2) was stable against heating. The helix of poly(2) was relatively stable to the addition of MeOH, but largely affected by the composition of CHCl~3~ and toluene. Poly(1) exhibited no clear oxidation peak, but a clear reduction peak at 0.65 V in cyclic voltammetry. Poly(1) and poly(2) showed liquid crystalline properties.

magnified image