Solvent effects on the folding of o-phenylene oligomers.
Solvent effects on the folding of o-phenylene oligomers.
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溶剂对邻亚苯基低聚物折叠的影响。
DOI：
10.1039/c6ob02512a
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发表时间：
2017
影响因子：
3.2
通讯作者：
Hartley,CScott
中科院分区：
文献类型：
--
作者：
Vemuri,GopiNath;Chu,Meng;Dong,Han;Spinello,BrianJ;Hartley,CScott
邻亚苯基低聚物在溶液中折叠成紧凑的螺旋构象，因此最近作为一类折叠体出现。先前的工作表明，它们的折叠是由平行于螺旋轴的芳烃-芳烃堆积相互作用控制的。可以合理地预期这种相互作用对溶剂敏感，但对该系统中溶剂的影响知之甚少。在这里，我们报告了一组代表性邻亚苯基低聚物在非极性（苯）到极性和质子（甲醇和水）溶剂中的行为。这些低聚物是通过点击化学进行低聚后官能化合成的。它们的折叠在所有研究的溶剂中都很好，但随着溶剂介电常数的增加而变得明显更差。因此，与许多其他类别的芳香折叠聚合物的行为相反，邻亚苯基的折叠倾向似乎并未受到疏溶剂效应的强烈影响。相反，“磨损结束”状态的更大极性支配着它们的行为。
ortho-Phenylene oligomers fold into compact helical conformations in solution, and have therefore recently emerged as a class of foldamers. Previous work has shown that their folding is controlled by arene–arene stacking interactions parallel to the helical axis. Such interactions might reasonably be expected to be sensitive to solvent, but little is known of solvent effects in this system. Here, we report on the behavior of a representative set of o-phenylene oligomers in solvents ranging from non-polar (benzene) to polar and protic (methanol and water). The oligomers have been synthesized using post-oligomerization functionalization by click chemistry. Their folding is good in all solvents studied, but becomes measurably worse as the dielectric constant of the solvent increases. Thus, in contrast to the behavior of many other classes of aromatic foldamers, the folding propensity of o-phenylenes does not appear to be strongly affected by the solvophobic effect. Instead, the greater polarity of “frayed end” states governs their behavior.