Regulating the Structures of Self-Assembled Mechanically Interlocked Moleculecular Constructs via Dianion Precursor Substituent Effects
Regulating the Structures of Self-Assembled Mechanically Interlocked Moleculecular Constructs via Dianion Precursor Substituent Effects
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DOI：
10.1021/jacs.9b13473
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发表时间：
2020-04-22
影响因子：
15
通讯作者：
Gong, Han-Yuan
中科院分区：
文献类型：
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作者：
Chen, Xu-Lang;Shen, Yun-Jia;Gong, Han-Yuan
取代基效应在调控反应化学和超分子自组装过程中起着关键作用。使用取代的对苯二甲酸酯二价阴离子（对苯二甲酸二价阴离子; PTADA），根据它们调节四价阳离子大环（环[2]）的固有阴离子络合特征的能力，探索了改变取代基的类型、数目和位置的效果。（2，6-二（1H-咪唑-1-基）吡啶）[2]（1，4-二亚甲基苯）（称为德克萨斯州大小的分子盒; 1（4+）），以其在DMSO中的tetrakis-PF 6-盐的形式。发现几种测试的取代基，包括2-OH、2，5-二（OH）、2，5-二（NH 2）、2，5-二（Me）、2，5-二（Cl）、2，5-二（Br）和2，5-二（I），与在母体PTADA系统中所看到的相反，促进了伪轮烷的形成。PTADA的其他衍生物，包括具有2，3-二（OH）、2，6-二（OH）、2，5-二（OMe）、2，3，5，6-四（Cl）和2，3，5，6-四（F）取代基的那些，仅导致所谓的外部结合，其中阴离子与大环腔外部的1（4+）相互作用。当反应组分包括额外的金属阳离子（M）时，发现通过选择PTADA衍生物产生的不同结合模式调节进一步的超分子自组装。根据PTADA衍生物和金属阳离子（M = Co 2+、Ni 2+、Zn 2+、Cd 2+、Gd 3+、Nd 3+、Eu 3+、Sm 3+、Tb 3+）的具体选择，可以稳定涉及一维聚轮烷、外部型轮烷化超分子有机框架（RSOF）或二维金属有机轮烷框架（MORF）的构建体。发现取代基的存在和性质决定了使用给定阳离子获得哪种特定的高阶自组装结构。在2，5-二（OH）、2，5-二（Cl）和2，5-二（Br）PTADA衍生物和Eu 3+的特定情况下，可以产生具有不同荧光发射性质的所谓MORF。目前的工作是为了说明如何小的变化，客人的替代模式可以用来控制结构远远超出了第一个相互作用领域。
Substituent effects play critical roles in both modulating reaction chemistry and supramolecular self-assembly processes. Using substituted terephthalate dianions (p-phthalic acid dianions; PTADAs), the effect of varying the type, number, and position of the substituents was explored in terms of their ability to regulate the inherent anion complexation features of a tetracationic macrocycle, cyclo[2](2,6-di(1H-imidazol- 1-yl)pyridine)[2](1,4-dimethylenebenzene) (referred to as the Texas-sized molecular box; 1(4+)), in the form of its tetrakis-PF6- salt in DMSO. Several of the tested substituents, including 2-OH, 2,5-di(OH), 2,5-di(NH2), 2,5-di(Me), 2,5-di(Cl), 2,5-di(Br), and 2,5-di(I), were found to promote pseudorotaxane formation in contrast to what was seen for the parent PTADA system. Other derivatives of PTADA, including those with 2,3-di(OH), 2,6-di(OH), 2,5-di(OMe), 2,3,5,6-tetra(Cl), and 2,3,5,6-tetra(F) substituents, led only to so-called outside binding, where the anion interacts with 1(4+) on the outside of the macrocyclic cavity. The differing binding modes produced by the choice of PTADA derivative were found to regulate further supramolecular self-assembly when the reaction components included additional metal cations (M). Depending on the specific choice of PTADA derivatives and metal cations (M = Co2+, Ni2+, Zn2+, Cd2+, Gd3+, Nd3+, Eu3+, Sm3+, Tb3+), constructs involving one-dimensional polyrotaxanes, outside-type rotaxanated supramolecular organic frameworks (RSOFs), or two-dimensional metalorganic rotaxane frameworks (MORFs) could be stabilized. The presence and nature of the substituent were found to dictate which specific higher order self-assembled structure was obtained using a given cation. In the specific case of the 2,5-di(OH), 2,5-di(Cl), and 2,5-di(Br) PTADA derivatives and Eu3+, so-called MORFs with distinct fluorescence emission properties could be produced. The present work serves to illustrate how small changes in guest substitution patterns may be used to control structure well beyond the first interaction sphere.