Tuning Supramolecular Polymer Assembly through Stereoelectronic Interactions
Tuning Supramolecular Polymer Assembly through Stereoelectronic Interactions
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DOI：
10.1021/jacs.1c05522
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发表时间：
2021-08-04
影响因子：
15
通讯作者：
Castellano, Ronald K.
中科院分区：
文献类型：
--
作者：
Henderson, Will R.;Liu, Guancen;Castellano, Ronald K.
本文报道了2，11-二硫杂[3.3]对环芳烃通过分子间氢键和跨环酰胺氢键的超分子聚合。酰胺氢键单元和中心桥原子之间的n-gt；pi*相互作用是碳原子与硫原子单点交换的结果。这种轨道供体-受体相互作用可以通过将硫化物氧化成砜来加强，从而缩短供体中心点受体距离，增加轨道重叠。N->；pi*相互作用增强的实验特征包括溶液中更大的等键聚合伸长常数，特征键伸长频率的变化，以及X射线结晶学评估的几何/结构变化。实验数据得到了2，11-二硫[3.3]对环番组装和未组装的大量计算研究的支持，以及一个合理设计的模型系统来证实立体电子效应在超分子聚合物组装中的作用。
The supramolecular polymerization of 2,11-dithia[3.3]paracyclophanes through self-complementary intermolecular and transannular amide hydrogen bonding is presented. An n -> pi* interaction between the amide hydrogen bonding units and the central bridging atom results from the single-point exchange of a carbon atom for a sulfur atom. This orbital donor-acceptor interaction can be strengthened by oxidizing the sulfide to a sulfone which acts to shorten the donor center dot center dot center dot acceptor distance and increase orbital overlap. Experimental signatures of the increased n -> pi* interaction include larger isodesmic polymerization elongation constants in solution, changes in characteristic bond stretching frequencies, and geometric/structural changes evaluated by X-ray crystallography. The experimental data are supported by extensive computational investigations of both assembling and nonassembling 2,11-dithia[3.3]paracyclophanes as well as a rationally designed model system to confirm the role of stereoelectronic effects on supramolecular polymer assembly.