Helix-Sense-Selective Polymerization of Achiral Phenylacetylenes with Two N-Alkylamide Groups to Generate the One-Handed Helical Polymers Stabilized by Intramolecular Hydrogen Bonds

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• 作者：Masahiro Teraguchi ; Daisuke Tanioka ; Takashi Kaneko ; Toshiki Aoki
• 刊名：ACS Macro Letters
• 出版年：2012
• 出版时间：November 20, 2012
• 年：2012
• 卷：1
• 期：11
• 页码：1258-1261
• 全文大小：218K
• 年卷期：v.1,no.11(November 20, 2012)
• ISSN：2161-1653

文摘

In this study, we investigated the helix-sense-selective polymerizations of newly synthesized achiral phenylacetylenes having two N-alkylamide groups, such as 3,5-bis(dodecylamide)phenylacetylene (DAPA), 3,5-bis(octylamide)phenylacetylene (OAPA), and 3,5-bis(butylamide)phenylacetylene (BAPA), by using a chiral rhodium catalyst system ([Rh(nbd)Cl]₂-(R)-(+)-1-phenylethylamine [(R)-PEA]). Poly(BAPA) was insoluble in any solvents. On the other hand, poly(DAPA) and poly(OAPA) were soluble in toluene, THF, and CHCl₃, and the obtained polymers showed intense circular dichroism signals at the absorption region of the main chain in the UV鈥搗is region. This result suggested those polymers were present in helical conformations with an excess of one-handed screw sense. The chiral helix structures of the formed polymers were stable in toluene at room temperature for a long time because of intramolecular hydrogen bonds. This result is the second example about polyacetylenes with one-handed helical conformation stabilized by intramolecular hydrogen bonds.