Molecularclip 1 remains monomeric in water and engages in host–guest recognition processes with suitable guests. We report the Ka values for 32 1⋅guest complexes measured by 1H NMR, UV/Vis, and fluorescence titrations. The cavity of 1 is shaped by aromatic surfaces of negative electrostatic potential and therefore displays high affinity and selectivity for planar and cationic aromatic guests that
分子夹1在水中仍然是单体,并与合适的客人一起参与宿主-客体识别过程。我们报告了通过1 H NMR,UV / Vis和荧光滴定法测得的32个1⋅客体配合物的K a值。1的腔体由负电势的芳族表面形成,因此对平面和阳离子芳族客体显示出高亲和力和选择性,这使其与CB [ n ]受体相区别,后者比脂族客体更喜欢脂肪族。静电作用在识别过程中起着主要作用,在此过程中,铵离子和C = O的1个基团之间可能发生离子-偶极相互作用。情况下,SO之间3 -基团的1和在来宾悬垂阳离子基团,和空腔内1由阳离子-π相互作用。宿主1对具有大的平面芳族表面(例如萘二酰亚胺NDI +和per二酰亚胺PDI +)和衍生自a啶的阳离子染料(例如亚甲基蓝和天蓝色A)表现出较高的亲和力。通过比较类似的中性和阳离子客体(例如,亚甲基紫与亚甲基蓝;喹啉与N-甲基喹啉鎓; a啶与N-甲基ac啶;中性红与中性红H +)可以确定阳离子-π相
Understanding the binding properties of phosphorylated glycoluril-derived molecular tweezers and selective nanomolar binding of natural polyamines in aqueous solution
A modular synthetic platform for the construction of flexible glycoluril-derived molecular tweezers was developed. The binding properties of four exemplary supramolecular hosts obtained via this approach towards 16 organic amines were investigated by means of 1H NMR titration. In this work, we compare the Ka values obtained this way with those of three structurally related molecular tweezers and provide
开发了用于构建柔性甘脲衍生分子镊子的模块化合成平台。通过1 H NMR 滴定研究了通过这种方法获得的四种示例性超分子主体对 16 种有机胺的结合性质。在这项工作中,我们将通过这种方式获得的K a值与三个结构相关的分子镊子的值进行比较,并提供一种计算方法来解释这些新型宿主的观察到的行为。结果表明,某些结构修饰导致天然多胺的非常有效和选择性结合,观察到的精胺结合低于 10 nM。
Effects of organic ammonium cations on the isolation of {Ti<sub>4</sub>} cyclic clusters from water: an <sup>17</sup>O NMR study
作者:Weiming Liu、Caiyun Liu、Wenli Wu、Guanyun Zhang、Jian Zhang、Chen-Ho Tung、Yifeng Wang
DOI:10.1039/d0dt00165a
日期:——
Ti-oxo species in water under highly acidic conditions. SO42- enhanced the condensation of Ti4+ by binding to the TOC species. OACs could not enhance the condensation of Ti4+ but could change the solution speciation and especially promote the formation of Ti18O27} clusters. We speculate that OACs interact with the cationic/neutral TOCs through anionic bridges to change the speciation. Under the synthetic
对于没有有机配体的含水Ti-oxo团簇(TOC)的制备,有机铵阳离子(OAC)是重要的,但机理尚不清楚。在这里,选择Ti4 + / SO42-系统作为模型来研究OAC的作用。用不同的阳离子添加剂从该系统中分离出三个Ti4}簇。结构分析揭示了OAC的结构作用:有机层中OAC的分层有序排列负责晶体沉淀物的稳定性和形成。17 O NMR光谱用于研究OAC和SO42-与高酸性条件下水中的Ti-oxo的相互作用。SO42-通过与TOC物种结合而增强了Ti4 +的缩合。OAC不能增强Ti4 +的缩合,但可以改变溶液的形态,特别是促进Ti18O27}团簇的形成。我们推测OAC通过阴离子桥与阳离子/中性TOC相互作用来改变物种。在Ti4}的合成条件下,Ti18O27}是溶液中的原始TOC,而Ti4}不是。
作者:Wenxian Ma、Tingting Cheng、Fang‐Zi Liu、Yan Liu、KaKing Yan
DOI:10.1002/anie.202202213
日期:2022.4.25
Analogous to allosteric enzymes, guest binding introduces a directional pulling or pushing force that acts on the reverse side of a Zn salen complex. This tunable intramolecular force promotes various degrees of conformational and torsional strain, as predicted by both classical conformational analysis and DFT. This strain energy can be further applied to cleave chemical bonds, and the efficiency can
A Modular Phosphorylated Glycoluril‐Derived Molecular Tweezer for Potent Binding of Aliphatic Diamines
作者:Michael Heilmann、Konrad Tiefenbacher
DOI:10.1002/chem.201902556
日期:2019.10.8
capable of binding organic amines in aqueous solution. This work reports the Ka values for 30 complexes of this molecular tweezer and amine guests, determined by means of 1 H NMR titrations. Both the hydrophobic cavity and the phosphate groups contribute to the binding. Bulkier molecules and molecules bearing negatively charged groups like carboxylates in amino acids bind less tightly due to a steric clash
合成了基于带有四个磷酸酯基团的基于甘脲的骨架的分子镊子,该分子镊子能够结合水溶液中的有机胺。这项工作报告了通过1 H NMR滴定确定的该分子镊子和胺客体的30种配合物的Ka值。疏水腔和磷酸基团均有助于结合。由于空间冲突和库仑排斥,较松散的分子和带有负电荷基团的分子(如氨基酸中的羧酸盐)的结合较不紧密。磷酸基团与铵客体的狭窄空腔和强离子相互作用有利于脂肪族二胺的结合。这些结合特性使该系统与结构上相关的分子夹和镊子明显区分开。