Goswami Ayona, Çınaroğlu Süleyman Selim, Singh Noor, Zavalij Peter Y, Mobley David L, Isaacs Lyle
Department of Chemistry and Biochemistry, University of Maryland, College Park, College Park, Maryland, 20742, United States.
Department of Pharmaceutical Sciences and Department of Chemistry, University of California, Irvine, Irvine, California, 92697, United States.
Chemistry. 2025 Feb 12;31(9):e202404024. doi: 10.1002/chem.202404024. Epub 2024 Dec 10.
We report the synthesis and characterization of sulfated pillar[5]arene hosts (P5S-P5S) that differ in the number of sulfate substituents. All five P5S hosts display high solubility in water (73-131 mM) and do not undergo significant self-association according to H NMR dilution experiments. The x-ray crystal structures of P5S, P5S ⋅ MeHDA, P5S ⋅ MeHDA, and P5S ⋅ MeHDA reveal one intracavity molecule of MeHDA and several external molecules of MeHDA which form a network of close methonium ⋅ ⋅ ⋅ sulfate interactions. The thermodynamic parameters of complexation between P5S and the panel of guests was measured by direct or competitive isothermal titration calorimetry. We find that the binding free energy toward a guest becomes more negative as the number of sulfate substituents increase. Conversely, the binding free energy of a specific sulfated pillar[5]arene toward a homologous series of guests becomes more negative as the number of NMe groups increases. The ability to tune the host ⋅ guest affinity by changing the number of sulfate substituents will be valuable in supramolecular polymers, separation materials, and latching applications.
我们报道了硫酸根取代基数不同的硫酸化柱[5]芳烃主体（P5S - P5S）的合成与表征。根据核磁共振氢谱稀释实验，所有五种P5S主体在水中均表现出高溶解性（73 - 131 mM）且不会发生显著的自缔合。P5S、P5S·MeHDA、P5S·MeHDA和P5S·MeHDA的X射线晶体结构表明，每个腔内有一个MeHDA分子，还有几个外部的MeHDA分子，它们形成了一个紧密的甲铵·····硫酸盐相互作用网络。通过直接或竞争等温滴定量热法测量了P5S与一系列客体之间络合的热力学参数。我们发现，随着硫酸根取代基数目的增加，主体对客体的结合自由能变得更负。相反，特定硫酸化柱[5]芳烃对一系列同系客体的结合自由能随着NMe基团数目的增加而变得更负。通过改变硫酸根取代基数来调节主体 - 客体亲和力的能力在超分子聚合物、分离材料和锁合应用中具有重要价值。
