Cucurbit[8]uril forms tight inclusion complexes with cationic triamantanes
Cucurbit[8]uril forms tight inclusion complexes with cationic triamantanes
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葫芦[8]脲与阳离子三金刚烷形成紧密包合物
DOI：
10.1039/d3nj00156c
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发表时间：
2023
影响因子：
3.3
通讯作者：
Isaacs, Lyle
中科院分区：
文献类型：
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作者：
King, David;Šumanovac, Tatjana;Murkli, Steven;Schreiner, Peter R.;Šekutor, Marina;Isaacs, Lyle
我们报道了通过相应的伯铵离子 G2 和 G4 的全甲基化合成季（二）阳离子三金刚烷衍生物 G1 和 G3。通过 1H NMR 光谱检查了 G1-G4 对 CB[7] 和 CB[8] 的络合行为，结果表明 CB[8] 能够完全包封 G1-G4，而 CB[7] 与 G1、G2 和 G4 形成包合物，但不能完全包封双季铵离子 G3 的中央疏水核。 CB[n]-客体配合物的几何形状是通过分析络合引起的化学位移变化来确定的，并通过使用基于 GFN 方法的 Conformer-Rotamer Ensemble Sampling Tool (CREST) 的分子建模进一步证实。最后，通过结合 1H NMR 竞争性实验、直接等温滴定量热法 (ITC) 测量以及使用紧密结合的三元络合物作为竞争剂的竞争性 ITC 滴定来确定络合热力学。
We report the synthesis of quaternary (di)cationic triamantane derivatives G1 and G3 by the permethylation of the corresponding primary ammonium ions G2 and G4. The complexation behaviors of G1–G4 toward CB[7] and CB[8] were examined by 1H NMR spectroscopy, which reveals that CB[8] is capable of fully encapsulating G1–G4 whereas CB[7] forms inclusion complexes with G1, G2, and G4 but cannot fully encapsulate the central hydrophobic core of the bis-quaternary ammonium ion G3. The geometries of the CB[n]-guest complexes were determined by analyzing the complexation induced changes in chemical shifts and were further confirmed by molecular modelling using the Conformer–Rotamer Ensemble Sampling Tool (CREST) based on the GFN methods. Finally, the complexation thermodynamics were determined by a combination of 1H NMR competitive experiments, direct isothermal titration calorimetry (ITC) measurements, and competitive ITC titrations using a tight binding ternary complex as a competitor.