Steric Control over the Threading of Pyrophosphonates with One or Two Cyanostar Macrocycles during Pseudorotaxane Formation
Steric Control over the Threading of Pyrophosphonates with One or Two Cyanostar Macrocycles during Pseudorotaxane Formation
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DOI：
10.1002/chem.202300899
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发表时间：
2023-06-09
影响因子：
4.3
通讯作者：
von Delius，Max
中科院分区：
文献类型：
--
作者：
Vogel，Julian;Chen，Yusheng;von Delius，Max
阴离子的超分子识别越来越多地用于实现超分子结构的自组装，从笼和聚合物到（假）轮烷。氰星（CS）大环先前已被证明与有机磷酸根阴离子形成2：1的络合物，可以通过加塞转化为[3]轮烷。在这里，我们首次实现了对包含氰基大环和基于有机焦膦酸酯的线的伪轮烷组装的空间控制。螺纹上空间体积的细微差异允许形成[3]伪轮烷或[2]伪轮烷。我们证明，线程动力学是由有机焦膦酸酯的空间需求，并在一种情况下，减慢到分钟的时间尺度。计算表明，大环内的二价阴离子是空间偏移的。我们的发现拓宽了cyanostar-阴离子组装体的范围，并且可能与方向性是相对缓慢滑动的结果的分子机器的设计相关。
The supramolecular recognition of anions is increasingly harnessed to achieve the self‐assembly of supramolecular architectures, ranging from cages and polymers to (pseudo)rotaxanes. The cyanostar (CS) macrocycle has previously been shown to form 2 : 1 complexes with organophosphate anions that can be turned into [3]rotaxanes by stoppering. Here we achieved steric control over the assembly of pseudorotaxanes comprising the cyanostar macrocycle and a thread that is based, for the first time, on organo‐pyrophosphonates. Subtle differences in steric bulk on the threads allowed formation of either [3]pseudorotaxanes or [2]pseudorotaxanes. We demonstrate that the threading kinetics are governed by the steric demand of the organo‐pyrophosphonates and in one case, slows down to the timescale of minutes. Calculations show that the dianions are sterically offset inside the macrocycles. Our findings broaden the scope of cyanostar‐anion assemblies and may have relevance for the design of molecular machines whose directionality is a result of relatively slow slipping.