Aminomethylenehelicene Oligomers Possessing Flexible Two-atom Linker Form a Stimuli-Responsive Double-Helix in Solution
Aminomethylenehelicene Oligomers Possessing Flexible Two-atom Linker Form a Stimuli-Responsive Double-Helix in Solution
复制标题
具有柔性双原子连接基的氨基亚甲基螺旋烯低聚物在溶液中形成刺激响应性双螺旋
DOI：
10.1002/ajoc.201402065
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发表时间：
2014
影响因子：
2.7
通讯作者：
Masahiko Yamaguchi
中科院分区：
文献类型：
--
作者：
Masanori Shigeno;Masahiko Sato;Yo Kushida;Masahiko Yamaguchi
以甲酰化螺烯为原料，通过还原胺化反应合成了低至(M)-七聚体的氨亚甲基螺烯齐聚物。含有三个以上螺烯的低聚物在1，3-二氟苯中形成双螺旋。加热至60 °C时，(M)-四聚体和(M)-五聚体呈无规卷曲，而(M)-六聚体在相同温度下仅轻微展开。在降温和升温过程中，(M)-四聚体和(M)-五聚体的结构变化存在双侧热滞后现象。(M)-五聚体和(M)-六聚体随着三氟乙酸的加入而展开，并且随着三乙胺的加入而重新形成双螺旋。
Aminomethylenehelicene oligomers up to the (M)‐heptamer were synthesized by reductive amination from a formylhelicene building block. The oligomers containing more than three helicenes formed a double helix in 1,3‐dilfuorobenzene. The (M)‐tetramer and (M)‐pentamer unfolded into a random coil by heating to 60 °C, whereas the (M)‐hexamer only slightly unfolded at the same temperature. A two‐sided thermal hysteresis was detected in the structural change of the (M)‐tetramer and (M)‐pentamer during cooling and heating. The (M)‐pentamer and (M)‐hexamer unfolded with the addition of trifluoroacetic acid and regenerated a double helix with the addition of triethylamine.