Sequential self-catalytic reactions in the formation of hetero-double-helix and their self-assembled gels by pseudoenantiomer mixtures of ethynylhelicene oligomers
Sequential self-catalytic reactions in the formation of hetero-double-helix and their self-assembled gels by pseudoenantiomer mixtures of ethynylhelicene oligomers
复制标题
乙炔基螺烯低聚物的假对映体混合物形成异双螺旋及其自组装凝胶的顺序自催化反应
DOI：
10.1002/chir.23224
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发表时间：
2020
期刊：
影响因子：
2
通讯作者：
Yamaguchi Masahiko
中科院分区：
文献类型：
--
作者：
Sawato Tsukasa;Yamaguchi Masahiko
假对映体乙炔螺旋(P)-五聚体和(M)-四聚体在甲苯中以1：1的比例混合形成异双螺旋及其自组装凝胶。等温条件下的动力学分析表明，温度变化是一个复杂的非线性性质。在60℃时，观察到S型动力学，用自组装凝胶播种后，S型动力学消失。这些发现表明参与了自催化反应I，在该反应中，杂双螺旋催化反应从无规螺旋形成杂双螺旋。在20℃时，观察到阶梯状的两相动力学，播种后动力学消失。这一现象可以通过两个具有S型反应动力学的反应来解释，即异双螺旋通过自催化反应II形成自组装凝胶I和自催化反应III形成自组装凝胶II。在90℃到5℃之间的恒速温度变化实验显示出非Sigmoid热滞，这与不同反应速率的顺序自催化反应有关。
A 1:1 mixture of pseudoenantiomer ethynylhelicene (P)‐pentamer and (M)‐tetramer in toluene formed hetero‐double‐helix and their self‐assembled gels. Kinetic analysis under isothermal conditions showed a complex nonlinear nature with regard to temperature changes. At 60°C, sigmoidal kinetics were observed, which disappeared after seeding with the self‐assembled gels. These findings indicate the involvement of self‐catalytic reaction I, in which a hetero‐double‐helix catalyzes the reaction to form a hetero‐double‐helix from random‐coils. At 20°C, stairwise biphasic kinetics were observed, which disappeared after seeding. This phenomenon was explained by the involvement of two reactions with sigmoidal kinetics, namely, the formation of self‐assembled gel I from hetero‐double‐helix by self‐catalytic reaction II and the formation of self‐assembled gel II by self‐catalytic reaction III. Constant‐rate temperature change experiments between 90 and 5°C showed nonsigmoidal thermal hysteresis in accordance with the involvement of sequential self‐catalytic reactions with different reaction rates.