Ultra‐Tight Host‐Guest Binding with Exceptionally Strong Positive Cooperativity
Ultra‐Tight Host‐Guest Binding with Exceptionally Strong Positive Cooperativity
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超紧主客绑定，正协同性极强
DOI：
10.1002/anie.202213467
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Gong, Bing
中科院分区：
文献类型：
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作者：
Sobiech, Thomas A.;Zhong, Yulong;Miller, Daniel P.;McGrath, Jillian K.;Scalzo, Christina T.;Redington, Morgan C.;Zurek, Eva;Gong, Bing
协同性在自组装和分子识别中起着关键作用。在高极性DMF中，具有环向骨架的刚性芳香族低聚酰胺大环与基于DABCO的阳离子客体以2：1的比例以高亲和力（K总= 1013M−2）结合。主客体结合也表现出非常强的正协同性，通过相互作用因子α定量，这是合成主客体系统中最大的。等温滴定量热法（ITC）揭示的异常强的正协同性，并通过质谱、NMR和计算研究得到充分证实，是由客体诱导的大环堆积和客体烷基末端链的稳定化驱动的，这种相互作用在结合第二个大环时出现。该体系具有非常强的正协同效应，为研究分子间相互作用和构建稳定的超分子组装体提供了一个可调的平台。
Cooperativity plays a critical role in self‐assembly and molecular recognition. A rigid aromatic oligoamide macrocycle with a cyclodirectional backbone binds with DABCO‐based cationic guests in a 2 : 1 ratio in high affinities (Ktotal≈1013M−2) in the highly polar DMF. The host–guest binding also exhibits exceptionally strong positive cooperativity quantified by interaction factors α that are among the largest for synthetic host–guest systems. The unusually strong positive cooperativity, revealed by isothermal titration calorimetry (ITC) and fully corroborated by mass spectrometry, NMR and computational studies, is driven by guest‐induced stacking of the macrocycles and stabilization from the alkyl end chains of the guests, interactions that appear upon binding the second macrocycle. With its tight binding driven by extraordinary positive cooperativity, this host–guest system provides a tunable platform for studying molecular interactions and for constructing stable supramolecular assemblies.