Supramolecular Assemblies of Phosphorylated Cavitands

The recent results in the chemistry of cavitands have proved that they are very efficient molecular receptors and potential precursors of molecular devices. In this context, we have investigated the synthesis and binding properties of phosphorylated cavitands. The stereoselective synthesis and the structural studies of the new compounds showed that these bowl-shaped molecules possess a well defined aromatic cavity surrounded by four phosphoryl groups (P=O or P=S). They are very efficient ligands for metal and organic cations. They are able to encapsulate cationic species by cooperative effect of the preorganized aromatic cavity and the four phosphorylated groups. Moreover, the upper and lower rim functionalitics can lead to the formation of molecular capsules and supramolecular assemblies whose properties and structures have been investigated by X-ray diffraction and NMR studies in solution.     

A Structural Study of Tautomerism and Hydrogen-Bonding in Supramolecular Assemblies

The synthesis and X-ray structures of four new crystalline materials incorporating ’dimers’ assembled from two different units possessing complementary hydrogen bonding motifs are reported; namely, phthalimide and 3-iminoisoindolinone or 2-guanidinobenzimidazole (or selected methylated derivatives) and 2-guanidinobenzoxazole. The bonding within each dimer involves a triplet of hydrogen bonds. The extended supramolecular structures are compared with each other as well as with two related structures described previously. The effect of using complementary DAD/ADA motifs that are not symmetrical on the respective supramolecular structures is also examined as is the prospect of incorporating different tautomeric components into the supramolecular structures. The presence of a very short, proton-transferred hydrogen bond within the respective triplets is also discussed.     

J-Type Aggregates of the Anionic Meso-Tetrakis(4-Sulfonatophenyl)Porphine Induced by ‚Hindered’ Cationic Porphyrins

Abstract

Porphyrin aggregation is a field of wide interest owing to the possible technological and biomedical applications. Under these premises, the possibility of tuning and driving the assembly processes turns out to have a central role in achieving specific structures and, therefore, functions. Recently, we have demonstrated that self-aggregation of water-soluble porphyrins on opposite charged polymeric templates is not simply related to the tendency of a given porphyrin towards aggregation, but is driven by specific molecular recognition processes. ^1–3     

Macrocycle-Based Crystalline Supramolecular Assemblies Built with Intermolecular Charge-Transfer Interactions

Synthetic macrocycles have served as principal tools for supramolecular chemistry, have greatly extended the scope of organic charge transfer (CT) complexes, and have proved to be of great practical value in the solid state during the past few years. In this Minireview, we summarize the research progress on the macrocycle-based crystalline supramolecular assemblies primarily driven by intermolecular CT interactions (a.k.a. macrocycle-based crystalline CT assemblies, MCCAs for short), which are classified by their donor–acceptor (D-A) constituent elements, including simplex macrocyclic hosts, heterogeneous macrocyclic hosts, and host–guest D-A pairs. Particular attention will be focused on their diverse functions and applications, as well as the underlying CT mechanisms from the perspective of crystal engineering. Finally, the remaining challenges and prospects are outlined.     

界面超分子聚合

超分子聚合物诞生于高分子化学与超分子化学的交叉融合,一般是指单体间通过非共价键作用连接形成的聚合物,并在溶液或体相中表现出类似聚合物的性质。目前超分子聚合物一般通过均相溶液聚合制备得到,但溶液中的超分子聚合是一个自发的组装过程,具有浓度依赖性,组装过程不易可控。为解决此问题,研究人员可以将超分子聚合从均相溶液转移到界面,在界面上可控地制备超分子聚合物。通过界面聚合制备超分子聚合物具有一些独特的优势,如可以制备得到分子量更高的超分子聚合物,易于制备一些缺陷少、面积大、有序的二维超分子聚合物等。本文基于在液-液、气-液和固-液三种界面上制备超分子聚合物的一些代表性工作,介绍了界面超分子聚合方法和应用,并展望其未来发展。     

超分子有机框架:具有周期性孔结构的超分子聚合物

本文概述了水相周期性超分子有机框架(supramolecular organic frameworks,SOFs)的研究进展.首先介绍了水相超分子聚合物和多孔材料研究的背景,然后分别描述了二维单层、三维金刚石型和立方型SOF的构建、结构表征及功能.最后就SOF的未来应用前景做出了分析和展望.     

环糊精超分子组装体的研究进展

环糊精是由若干个D-吡喃葡萄糖单元通过α-1,4-糖苷键连接而成的环状低聚糖,具有一个亲水性的外表面和一个疏水性的空腔。利用主客体相互作用,环糊精及其衍生物能够选择性地与大小匹配的疏水性客体分子形成各种超分子包合物。本文概述了环糊精的结构与性质,并介绍了近年来国内外以环糊精为基础的纳米粒子、水凝胶等超分子组装体的设计原理、作用机制、刺激响应及应用特点,并对环糊精超分子组装体的前景进行了展望。     

卟啉及其类似物超分子功能的分析应用

应用超分子化学的理论和研究成果解决分离、分析与有关理论问题是现代分析化学的一个重要方面。评述了卟啉及其金属配合物、类似物的分子识别、组装和仿生催化作用及其在生物相关物质的色谱分离分析，各类传感器、模拟酶分析等方面的应用研究进展，也展望了发展趋势。引用文献８６篇。     

Stabilizing Liquids Using Interfacial Supramolecular Assemblies

Stabilizing liquids based on supramolecular assembly (non-covalent intermolecular interactions) has attracted significant interest, due to the increasing demand for soft, liquid-based devices where the shape of the liquid is far from the equilibrium spherical shape. The components comprising these interfacial assemblies must have sufficient binding energies to the interface to prevent their ejection from the interface when the assemblies are compressed. Here, we highlight recent advances in structuring liquids based on non-covalent intermolecular interactions. We describe some of the progress made that reveals structure–property relationships. In addition to treating advances, we discuss some of the limitations and provide a perspective on future directions to inspire further studies on structured liquids based on supramolecular assembly.     

Supramolecular enzyme mimics by self-assembly

The development of supramolecular chemistry has led to a shift in the research focus from the structural design of supramolecules to developing functional systems, such as supramolecular enzyme models. The supramolecular enzyme mimics can be readily constructed by self-assembly which is an efficient strategy for generating highly-ordered structures with complex and hierarchical architectures to mimic the biopolymers. The study of supramolecular enzyme mimics has implications for understanding both the structure–function relationships of natural enzymes and the thermodynamic mechanism during catalysis. Additionally, they are potentially useful in many important applications, e.g., medicinal application and industrial biocatalysts and so on. This review is aimed at giving a brief overview of the synthesis of supramolecular enzyme mimics and their functions.     

Supramolecular Self-organization of Potential Hydrogelators on Attracting Surfaces

This article highlights the aggregation behaviour of potential low molecular weight hydrogelators on attracting surfaces. Our goal was the development of a method, which enables the finding of new hydrogelators that are not easily recognizable as such because they only form instable or no hydrogels in aqueous solution. To this end, a series of negatively charges azo-dyes was synthesized and positive charged glass slides were immersed into their aqueous solutions. All dyes showed supramolecular organization and significant concentration on the attracting glass surface. Microscopic investigations mostly revealed the formation of crystals. However, one compound, (1-(2-n-octylphenylazo)-2-hydroxy-6-naphthalenesulphonate, selectively formed a hydrogel on the surface whereas it does not gel in aqueous solution. This reveals the hydrogel as the stable form of this compound under equilibrium conditions. This method of surface-induced hydrogelation might facilitate the identification of new hydrogelators. Further more, it might also allow the mimicking of surface gelation as a process of biological relevance.     

肽基超分子胶体

肽基超分子胶体是基于肽分子间超分子作用,自发形成且具有有序分子排布及规整结构,兼具传统胶体及超分子特性的组装体系。利用超分子弱相互作用构筑功能性胶体,不仅是人们对生命组装进程深入理解的有效手段,也是实现优异的超分子材料的重要途径。肽分子具有组成明确、性能可调、生物安全性高及可降解等优势,是超分子化学、胶体与界面化学领域重要的组装基元。基于肽的超分子自组装,能够实现多尺度、多功能的生物胶体的构筑,被广泛应用于医药、催化、能源等领域。如何通过对肽序列的设计及分子间作用力的调控,实现对胶体结构和功能的精确控制,是近年来研究的重要课题之一。从分子尺度研究和揭示超分子胶体的组装过程及物理化学机制,探究胶体结构与功能的关系,是实现超分子结构和功能化的重要内容。本文基于"分子间作用的调控"及"结构与功能的关系"两个基本科学问题,系统地综述了肽基超分子胶体的组装机制、结构与功能,以及研究现状。     

[60]富勒烯的超分子自组装研究进展

超分子自组装是发展超分子电子学的重要途径。随着纳米科学和技术的迅速发展,自组装技术已成功地应用于纳米尺度物质的维数、形貌和功能等的调控。作为构筑分子水平上一维、二维、三维有序功能结构和高有序分子聚集态结构的关键技术,超分子自组装技术有力地推动了具有优良光、电、磁性能的分子材料和纳米功能材料更深层次的研究。本文综述了超分子自组装在富勒烯科学领域的基础研究和应用,特别是对有利于自组织和自组装功能的富勒烯基衍生物的设计与合成、超分子作用力引导的具有特定结构的分子体系的可控自组装、以及富勒烯分子聚集态结构材料的光物理过程、超分子中电子转移和能量转移现象进行了描述;并对卟啉、四硫富瓦烯、碗烯和杯芳烃等一系列富π电子化合物和大环主体分子等包含[60]富勒烯的主体化合物的超分子作用和超分自组装体以及通过氢键、π-π作用、静电力和范德华力和金属配位作用形成的[60]富勒烯超分子自组装体进行了总结,对未来发展进行了展望。     

典型锕系超分子组装体的构筑原理及研究进展

锕系超分子化学是锕系元素化学的重要研究领域,可以为乏燃料后处理的配位化学基础研究提供重要信息,并为探索锕系功能材料在发光、传感、催化和分离等方面的功能应用提供关键材料体系。本文介绍了基于锕系金属离子的金属-有机超分子组装体这一新兴领域的最新研究进展。从锕系超分子组装体的构筑原理出发并结合笔者自身研究情况,对基于主客体准轮烷配体的锕系-轮烷配位聚合物、具有闭合结构的锕系配位组装体和基于超分子相互作用的锕系超分子聚合物这三类典型的锕系超分子组装体的研究进展进行了梳理和总结阐述。期望为未来新型锕系超分子组装体的设计合成提供参考,促进相关领域的进步和发展。     

Computational Study of Supramolecular Bis-porphyrin “Molecular Tweezers”

A computational study of a series of space separated bis-porphyrin “molecular tweezers” using semiempirical (AM1) and DFT (B3LYP and PBE1PBE) methods has been carried out. It was found that polynorbornane bis-porphyrin systems are significantly less rigid than previously thought. The variation of the metal–metal separation distance between the two porphyrin centers does not cause a significant energy change thus enabling these molecules to easily adjust to the optimal coordination distance required for complexation by various bidentate 4-pyridyl ligands inside the cavity of these “tweezers”. Article 54, ECCC-10, April 1-30 2005, http://www.eccc.monmouth.edu     

Hybrid Calixarene/Inorganic Salt/Diiodoperfluorocarbon Supramolecular Assemblies

1,3-Bis(α-picolyloxy)-p-tert-butylcalix[4]crown-5 in the cone conformation (2), 1,8-diiodoperfluorooctane or 1,6-diiodoperfluorohexane, and potassium iodide ternary mixtures undergo in solution self-sorting and afford crystalline “supramolecular salts”. These hybrid materials consist of supercation [K⁺ ? 2] and superanion [I–(CF₂) _n –I…I^? …I–(CF₂) _n –I…I^? …] (n = 6,8) components. In the supercations the potassium ion is embedded in the ionophoric pocket created by the heteroatoms present at the lower rim. In the superanions the iodide ions form infinite fluorous polyanionic chains as a result of a self-assembly process which relies on halogen bonding. Both cation encapsulation and anion-perfluorocarbon halogen bonding were detected in solution by ¹H and ¹⁹F NMR, and in the gas phase by ESI MS.     

Polymeric Carbon Nitride with Chirality Inherited from Supramolecular Assemblies

The facile synthesis of chiral materials is of paramount importance for various applications. Supramolecular preorganization of monomers for thermal polymerization has been proven as an effective tool to synthesize carbon and carbon nitride-based (CN) materials with ordered morphology and controlled properties. However, the transfer of an intrinsic chemical property, such as chirality from supramolecular assemblies to the final material after thermal condensation, was not shown. Here, we report the large-scale synthesis of chiral CN materials capable of enantioselective recognition. To achieve this, we designed supramolecular assemblies with a chiral center that remains intact at elevated temperatures. The optimized chiral CN demonstrates an enantiomeric preference of ca. 14 %; CN electrodes were also prepared and show stereoselective interactions with enantiomeric probes in electrochemical measurements. By adding chirality to the properties transferrable from monomers to the final product of a thermal polymerization, this study confirms the potential of using supramolecular precursors to produce carbon and CN materials and electrodes with designed chemical properties.     

Mn4-硫杂杯[4]芳烃单元的溶剂导向超分子组装

以去叔丁基硫杂杯[4]芳烃与Mn(II)为研究对象,通过改变体系溶剂分别得到了两个四核化合物Mn4(T4A)2 (1)和Mn4(T4A)2(DMF)2(2) (T4A = thiacalix[4]arene)。当反应溶剂为氯仿(CHCl3)和甲醇的混合溶剂时,形成的是以四核锰为结构单元的二维“笼目”(Kagomé)状超分子化合物1,而当反应溶剂为N,N-二甲基甲酰胺(DMF)和甲醇的混合溶剂时,得到的是格子状二维超分子互穿的三维结构化合物2。化合物1具有很大的溶剂占有空隙,是一个潜在的多孔材料,而化合物2是一个紧密堆积的拓展结构。