基于硫脲衍生物的钳形分子受体的晶体结构及其对F－离子的选择性识别

设计并在超声波辐射下合成了3种基于硫脲衍生物的氢键型钳形分子受体, 单晶结构表明该类主体分子可与DMF形成1∶1型氢键配合物. 在DMF中利用紫外-可见吸收光谱研究了其与4种卤素离子的相互作用, 发现该类中性受体可与阴离子形成主客体配合物, 表现为对F^－有识别作用, 而其它3种卤素离子的加入则无类似的光谱变化, 这可归因于F^－与主体化合物发生氢键作用. 计算表明, 主体与阴离子形成1∶1型的配合物, 结合能力随苯环上取代基亲电性不同而规律变化. ¹H NMR滴定进一步证实了氢键作用的存在及参与类型.     

基于硫脲基的钳型氟离子选择性识别受体

设计并在超声辐射下合成了三种基于硫脲衍生物的氢键型钳形分子受体，单晶结构表明主体分子RI可与DMF形成1:1型氢键配合物．并进一步通过分子内,分子间氢键及π–π堆积作用自足装成超分子体系. 在DMF中利用UV-vis 和¹H-NMR研究了其与四种卤素离子的相互作用，发现该类中性受体对F^-有选择性识别作用,并可与阴离子形成主客体配合物。研究表明，该类主体与阴离子首先形成1：1型氢键配合物，当阴离子浓度增大时则表现为脱质子过程。     

芳酰基硫脲受体的合成及对阴离子识别研究

设计合成了3种芳酰基硫脲受体分子. 利用紫外-可见吸收光谱考察了其与F^－, Cl^－, Br^－, AcO^－, HSO₄^－, H₂PO₄^－等阴离子的作用. 结果表明该类受体分子与阴离子形成氢键配合物. 加入F^－, AcO^－时, 溶液立刻由无色变为黄色, 而加入其它阴离子则无变化, 从而实现对这两种阴离子的裸眼识别. 结果表明受体分子与阴离子间形成1∶1型的配合物. ¹H NMR滴定及质子溶剂效应为受体分子与阴离子间的氢键作用本质提供了直接依据.     

密度泛函理论研究间硝基苯基吡咯酰胺识别卤素阴离子

采用混合密度泛函B3LYP方法, 在LANL2DZ水平上优化间硝基苯基吡咯酰胺(NPC)及其卤素阴离子复合物的几何构型, 从几何结构参数、电荷布居、前线轨道、结合能以及热力学参数等角度探讨复合物形成过程中主体分子的构象变化以及主客体间的超分子作用. 研究结果表明, 吡咯酰胺主体分子识别卤素阴离子是一个自发过程. 识别过程包括阴离子诱导下主体分子构象转变和“活性”构象与阴离子形成氢键两个步骤. 计算表明主体分子复合阴离子过程中, 两者的前线轨道发生作用, 电子容易从卤素阴离子的HOMO向主体分子的LUMO转移. 在所形成的四种复合物NPC-X^－ (X^－＝F^－, Cl^－, Br^－, I^－)中, 以NPC-F^－最稳定, 与文献报道吡咯酰胺主体分子识别卤素阴离子能力的实验结果相一致.     

人工合成受体的阴离子识别研究(Ⅰ)——乙二醛缩双芳氨基硫脲的合成及阴离子识别研究

设计合成了3种乙二醛缩双芳氨基硫脲受体分子。利用紫外-可见吸收光谱及¹H NMR考察了其与F^-、Cl^-、Br^-、I^-、CH₃COO^-、C₃H₇COO^-、HSO₄^-、NO₃^-等阴离子的作用。结果表明,该类受体分子与阴离子形成氢键配合物。加入F^-、CH₃COO^-、C₃H₇COO^-时,溶液颜色立刻由无色转变为深黄色,而加入其它阴离子则无变化,从而实现对这3种阴离子的裸眼检测。通过计算可知,随着苯环上取代基的变化,此3种受体分子对F^-和CH₃COO^-的识别作用呈现有规律的变化。即o-F取代基的受体分子对阴离子的识别作用大于其他2种受体分子,且主客体间形成1∶1的配合物。¹H NMR滴定及质子溶剂效应进一步证明了受体分子与阴离子之间以氢键作用方式相结合。     

新型手性不对称脲石胆酸分子裂缝的设计合成

以刚性的石胆酸甲酯为骨架, 手性不对称脲为侧链, 通过三光气桥连, 设计合成了一类新型的手性分子裂缝. 7个分子裂缝均为新化合物, 其结构均经¹H NMR, IR, MS和元素分析确证, 并且考察了其对卤素阴离子Cl^－, Br^－, I^－的识别性能. 初步的实验结果表明, 这类分子裂缝不仅可与所考察的卤素阴离子形成1∶1型超分子配合物, 而且对卤素阴离子具有良好的识别选择性.     

双芳酰基肼衍生物为受体应用于F -和AcO -的识别研究

设计合成了系列双芳酰基肼衍生物, 利用紫外-可见吸收光谱考察了在乙腈中受体与F^-、Cl^-、Br^-、AcO^-、H₂PO₄^-、HSO₄^-等阴离子的作用. 研究结果表明双芳酰基肼衍生物对F^-、AcO^-有高的选择性和敏感性, 而对其他阴离子则无明显作用. 该类受体分子与阴离子通过氢键作用形成1:1的稳定化合物,从而导致了吸收光谱的变化.¹H NMR 滴定为受体分子与阴离子间的氢键作用本质提供了直接依据.     

人工合成受体的阴离子识别研究（Ⅲ）:双缩氨基硫脲衍生物的合成及阴离子识别研究

利用简便方法高效的合成了三种双缩氨基硫脲衍生物受体分子。利用紫外-可见吸收光谱及¹H NMR考察了该三种受体分子的阴离子识别性能。结果表明，该类受体分子均对F^-，CH₃COO^-和H₂PO₄^-有较好的选择性识别作用，而对Cl^-，Br^-，I^-，HSO₄^-和NO₃^-没有明显作用。当在此三种受体分子的DMSO溶液中加入F^-，CH₃COO^-和H₂PO₄^-时，可用肉眼观察到溶液颜色立刻由无色转变为深黄色，而加入其它阴离子则无变化，因而当溶液中存在其它卤素阴离子时可利用此类受体分子检测F^-。通过计算可知，随着苯环上取代基的变化，此三种受体分子对F^-，CH₃COO^-和H₂PO₄^-的识别作用呈现有规律的变化。即对同种阴离子，其平衡常数为：受体1＞受体3＞受体2。且主客体间形成1:1的配合物。¹H NMR 滴定及质子溶剂效应进一步证明了受体分子与阴离子之间以氢键作用方式相结合。     

密度泛函理论研究DMSO溶剂中邻-二(吡咯-2-甲酰胺基)亚苯与卤素阴离子间的超分子作用

采用混合密度泛函B3LYP方法, 在LANL2DZ水平上优化DMSO溶剂中邻-二(吡咯-2-甲酰胺基)亚苯(PFP)及其卤素阴离子复合物的几何构型, 从几何结构参数、电荷布居、前线轨道、结合能以及热力学参数等角度探讨复合物形成过程中主体分子的构象变化以及主客体间的超分子作用. 研究结果表明, 邻-二(吡咯-2-甲酰胺基)亚苯识别卤素阴离子是一个自发过程. 复合阴离子过程中, 两者的前线轨道发生作用, 电子容易从卤素阴离子的HOMO向主体分子的LUMO转移. 在所形成的四种复合物PFP:X^－(X^－＝F^－, Cl^－, Br^－, I^－)中, 以PFP:F^－最稳定, 与文献报道邻-二(吡咯-2-甲酰胺基)亚苯识别卤素阴离子能力的实验结果相一致. 设计合成含多个吡咯酰胺基团、并能形成合适“杯口”大小的主体化合物, 将增强对卤素阴离子的识别能力.     

新型受体呋喃并[3’,4’:5,6]吡啶并[2,3-c]吡唑的合成及对阴离子的识别研究

设计并合成了5种呋喃并[3’,4’:5,6]吡啶并[2,3-c]吡唑受体分子, 利用紫外-可见吸收光谱考察了其与F－, Cl－, Br－, AcO－, 等阴离子的作用. 结果表明该类受体分子与阴离子形成氢键配合物, 导致呋喃并吡啶并吡唑受体的光谱发生变化. 测定了配合物的结合比和稳定常数, 发现受体化合物对F－, AcO－离子具有良好的选择性, 对其它多种阴离子无影响. Job曲线表明受体分子与阴离子间形成1∶1型的配合物.     

Thiourea Based Tweezer Anion Receptors for Selective Sensing of Fluoride Ions

Three 3,3＇-di（4-substituted-phenyl）-1,1＇-isophthaloylbis（thiourea） compounds were designed as novel neutral anion receptors, and synthesized by simple steps in good yields. The single crystal structure of receptor 1 shows that a solvent molecule was captured by the host molecule through intermolecular hydrogen bonding. Moreover, it was self-assembled as a supramolecular system for the presence of abundant inter- and intramolecular hydrogen bonding and π-π interactions between phenyl groups. Their application as anion receptors has been examined by UV-Vis and ^1H NMR spectroscopy, showing that they had a higher selectivity for fluoride than other halides. The host and guest formed a 1 ： 1 stoichiometry complex through hydrogen bonding interactions in the first step, then following a process of deprotonation in presence of an excess of F^- in the solvent of DMF.     

A Halogen‐Bonding Bis‐triazolium Rotaxane for Halide‐Selective Anion Recognition

A systematic study on the anion‐binding properties of acyclic halogen‐ and hydrogen‐bonding bis‐triazolium carbazole receptors is described. The halide‐binding potency of halogen‐bonding bis‐iodotriazolium carbazole receptors was found to be far superior to their hydrogen‐bonding bis‐triazolium‐based analogues. This led to the synthesis of a mixed halogen‐ and hydrogen‐bonding rotaxane host containing a bis‐iodotriazolium carbazole axle component. The rotaxane’s anion recognition properties, determined by ¹H NMR titration experiments in a competitive aqueous solvent mixture, demonstrated the preorganised halogen‐bonding interlocked host cavity to be halide‐selective, with a strong binding affinity for bromide.     

Halotriazolium Axle Functionalised [2]Rotaxanes for Anion Recognition: Investigating the Effects of Halogen‐Bond Donor and Preorganisation

The anion‐templated synthesis of three novel halogen‐bonding 5‐halo‐1,2,3‐triazolium axle containing [2]rotaxanes is described, and the effects of altering the nature of the halogen‐bond donor atom together with the degree of inter‐component preorganisation on the anion‐recognition properties of the interlocked host investigated. The ability of the bromotriazolium motif to direct the halide‐anion‐templated assembly of interpenetrated [2]pseudorotaxanes was studied initially; bromide was found to be the most effective template. As a consequence, bromide anion templation was used to synthesise the first bromotriazolium axle containing [2]rotaxane, the anion‐binding properties of which, determined by ¹H NMR spectroscopic titration experiments, revealed enhanced bromide and iodide recognition relative to a hydrogen‐bonding protic triazolium rotaxane analogue. Two halogen‐bonding [2]rotaxanes with bromo‐ and iodotriazolium motifs integrated into shortened axles designed to increase inter‐component preorganisation were also synthesised. Anion ¹H NMR spectroscopic titration experiments demonstrated that these rotaxanes were able to bind halide anions even more strongly, with the iodotriazolium axle integrated rotaxane capable of recognising halides in aqueous solvent media. Importantly, these observations suggest that a halogen‐bonding interlocked host binding domain, in combination with increased inter‐component preorganisation, are requisite design features for a potent anion receptor.     

Urea and thiourea based anion receptors in solution and on polymer supports

Herein we report the development of a new series of surface bound anion sensors exploiting the urea or thiourea motif capable of binding anions through hydrogen bonding interactions. The use of high resolution magic angle spinning ¹H NMR allows the direct comparison of the anion binding properties of these receptors in solution versus those tethered to polymer resins. Some intramolecular hydrogen bonding and solvent effects were observed at the solution:surface interface however in general the anion binding properties of the polymer bound urea and thiourea receptors were maintained.     

Oligoamide Foldamers as Helical Chloride Receptors—the Influence of Electron‐Withdrawing Substituents on Anion‐Binding Interactions

The anion‐binding properties of three closely related oligoamide foldamers were studied using NMR spectroscopy, isothermal titration calorimetry and mass spectrometry, as well as DFT calculations. The ¹H NMR spectra of the foldamers in [D₆]acetone solution revealed partial preorganization by intramolecular hydrogen bonding, which creates a suitable cavity for anion binding. The limited size of the cavity, however, enabled efficient binding by the inner amide protons only for the chloride anion resulting in the formation of a thermodynamically stable 1:1 complex. All 1:1 chloride complexes displayed a significant favourable contribution of the entropy term. Most likely, this is due to the release of ordered solvent molecules solvating the free foldamer and the anion to the bulk solution upon complex formation. The introduction of electron‐withdrawing substituents in foldamers 2 and 3 had only a slight effect on the thermodynamic constants for chloride binding compared to the parent receptor. Remarkably, the binding of chloride to foldamer 3 not only produced the expected 1:1 complex but also open aggregates with 1:2 (host:anion) stoichiometry.     

Anion Recognition with Antimony(III) and Bismuth(III) Triaryl-Based Pnictogen Bonding Receptors

The synthesis and characterisation of a library of acyclic antimony(III) and bismuth(III) triaryl pnictogen bonding (PnB) receptor systems are reported. In the first-generation receptor series, quantitative ¹H NMR chloride titration experiments in THF solvent media reveal halide anion binding potency is intimately correlated with both the electronic-withdrawing nature of the aryl- substituent and the polarisability of the PnB donor. Further extensive anion binding investigations with the most potent Sb- and Bi-based PnB receptors: 1⋅Sb^2CF3 and 1⋅Bi^2CF3 , reveal novel selectivity profiles, both displaying Cl⁻ selectivity relative to the heavier halides and, impressively, to a range of highly basic oxoanions. The synthesis and preliminary chloride anion binding studies of a series of novel tripodal tris-proto-triazole triaryl Sb(III) and Bi(III) mixed PnB-HB receptor systems are also described. Whereas parent triphenyl Sb(III) and Bi(III) compounds are incapable of binding Cl⁻ in THF solvent media, the PnB-triazole HB host systems exhibit notable halide affinity.     

Chloride‐Anion‐Templated Synthesis of a Strapped‐Porphyrin‐Containing Catenane Host System

The synthesis, structure and anion‐recognition properties of a new strapped‐porphyrin‐containing [2]catenane anion host system are described. The assembly of the catenane is directed by discrete chloride anion templation acting in synergy with secondary aromatic donor–acceptor and coordinative pyridine–zinc interactions. The [2]catenane incorporates a three‐dimensional, hydrogen‐bond‐donating anion‐binding pocket; solid‐state structural analysis of the catenane?chloride complex reveals that the chloride anion is encapsulated within the catenane’s interlocked binding cavity through six convergent CH????Cl and NH???Cl hydrogen‐bonding interactions and solution‐phase ¹H NMR titration experiments demonstrate that this complementary hydrogen‐bonding arrangement facilitates the selective recognition of chloride over larger halide anions in DMSO solution.     

氨基甲酸酯型脱氧胆酸分子钳对中性分子的识别性能研究

利用差紫外光谱法考察了新型分子钳1～6对苯胺、对硝基苯胺、对甲氧基苯胺等中性分子的识别性能, 测定了25 ℃下, 在CHCl₃中主客体间的结合常数(K_a)和自由能变化(ΔG⁰). 结果表明, 所有分子钳主体对所考察的客体分子显示良好的识别作用, 主客体间形成1∶1型主客体络合物. 识别作用的主要推动力为多重氢键和π-π重叠等的作用. 讨论了主客体间形状、大小匹配和几何互补及识别模式等因素对识别能力的影响, 并利用核磁共振氢谱与计算机模拟作为辅助手段对实验结果进行了解释.     

CH/π, CH/O弱氢键在2,6-二(α-苯基苄基)-1,5-萘二酚主体分子包结物构筑中的作用

设计、合成了一种新的主体分子2,6-二(α-苯基苄基)-1,5-萘二酚 (1). 它可与许多有机小分子形成配位包合物. 用IR和¹H NMR表征了配位包结物, 并测定了主客体分子的摩尔比: 1•DMF (1∶1), 1•DMSO (1∶2), 1•吡啶 (1∶1), 1•喹啉(1∶2), 1•N-甲基吡咯烷酮(1∶1). 用单晶X衍射分析了包结物 (1)•DMF的晶体结构, 属三斜晶系, 晶胞参数为P-1, a＝0.9085(9) nm, b＝0.9501(6) nm, c＝2.0995(6) nm, α＝99.59(3)°, β＝90.13(4)°, γ＝96.20(7)°, V＝1.776(2) nm³, D_c＝1.898 g•cm^－3. 结果表明, 主体分子间的CH/π弱氢键在决定主体分子的层状框架结构和客体分子在层间的填充方式中发挥了重要作用; 两种不等效的客体分子与主体分子的作用方式是不同的, 一种客体分子是通过CH/π, CH/O弱氢键与同层的不同主体分子相互作用, 另一种是通过CH/π, CH/O弱氢键与相邻层的不同主体分子相互作用.     

Easily‐prepared Hydroxy‐containing Receptors Recognize Anions in Aqueous Media

Despite their ready availability, O?H groups have received relatively little attention as anion recognition motifs. Here, we report two simple hydroxy‐containing anion receptors that are prepared in two facile steps followed by anion exchange, without the need for chromatographic purification at any stage. These receptors contain a pyridinium bis(amide) motif as well as hydroxyphenyl groups, and bind mono‐ and divalent anions in 9:1 CD₃CN:D₂O, showing a selectivity preference for sulfate. Notably, a “model” receptor that does not contain hydroxy groups shows only very weak sulfate binding in this competitive solvent mixture. In the solid state, X‐ray crystallographic studies show that the receptors tend to form extended assemblies with anions; however, ¹H and DOSY NMR studies as well as molecular dynamics simulations show that only 1:1 complexes are present in solution. Molecular dynamics simulations suggest that one of the receptors suffers from competing intramolecular hydrogen bonding, while another binds partially‐hydrated anions, with the receptor's O?H groups forming hydrogen bonds to water molecules within the anion's coordination sphere.