超分子聚合机理

与共价键聚合物由单体(M1)通过共价键连接不同,超分子聚合物是由单体(M2)通过非共价键连接而成的长链大分子。聚合包括分子聚合和超分子聚合。超分子聚合描述M2通过非共价键自组装形成超分子聚合物的过程,涉及氢键、π-π堆砌型和立体匹配等驱动力以及分子识别、协同性等特征,与M1通过共价键形成聚合物的过程(分子聚合)不同。为了理解超分子聚合物链结构形成机理,本文分析和讨论超分子聚合的三个主要机理:(1)线性链生长;(2)螺旋链生长;(3)拓扑链生长。     

超分子聚合物复合材料及其自愈合行为

超分子聚合物复合材料定义为纤维、填料等增强体均匀分散在超分子聚合物基体中的复合材料。根据超分子聚合物与增强体之间化学键连接的不同可分为三种类型:(1)无化学键;(2)共价键;(3)非共价键。超分子聚合物复合材料与分子聚合物复合材料共同组成了完整的聚合物复合材料体系。本文综述可自愈合的氢键、π-π堆叠和金属配位型超分子聚合物复合材料的研究进展。     

超分子自组装中的非共价键协同作用

本文综述了近年来氢键、π-π堆积作用、配位作用、供体-受体相互作用和疏溶剂作用等多种非共价键协同作用在超分子自组装研究中的新进展。     

多重氢键超分子聚合物

超分子聚合物是通过单体单元间的可逆非共价作用(包括氢键、π-π相互作用和金属配位作用等)形成的,由于非共价键的方向性和强度,这类聚合物显示了许多有趣的功能,例如刺激响应性和纳米结构自组装.本文总结了近三年来多重氢键超分子聚合物在改善聚合物性能、形成复杂分子构造、自组装纳米结构等方面的作用,并对超分子聚合物的应用进行了展...     

超分子树枝聚合物的起源与发展

超分子树枝聚合物起源于聚合物链结构的2个重要进化(树枝链和超分子),是通过建筑模块在芯、支化单元或表面的分子自组装(非共价键连接)生成的树枝聚合物,具有独特的结构特征和新颖的物理、化学等功能。超分子树枝聚合物的进一步自组织可形成液晶态或柱状体等有序结构。超分子树枝聚合物可分为氢键型、金属配位型、π-π堆叠型、离子型、拓扑型(含轮烷和索烃结构)、混合型(含2种或2种以上不同非共价键)等类型。本文综述各种类型超分子树枝聚合物的合成、结构、聚集态和应用。     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注。本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基(D)与吡啶基(A)作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述。     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注。本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基（D）与吡啶基（A）作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述。     

基于氢键作用结合的超分子聚合物

非共价键结合的超分子聚合物由于其特殊的结构及性能引起了广泛的关注.本文在介绍超分子化学、氢键及超分子聚合物的基础上,主要综述了以氢键为结合力的多重氢键作用、羧基(D)与吡啶基(A)作用以及氢键与其它非共价键协同作用形成的超分子聚合物体系,并对超分子聚合物的研究现状及前景进行了评述.     

基于杯芳烃主体的分子自组装研究进展

分子自组装是超分子化学最重要的研究内容之一. 杯芳烃作为继冠醚、环糊精之后的第三代人工合成受体分子已在分子自组装研究方面取得了重要进展并显示了广泛的应用前景. 主要综述杯芳烃衍生物通过氢键、金属诱导配位、π-π作用、疏水作用等非共价键弱相互作用力在溶液状态、固态和界面的分子自组装方面的研究进展.     

超分子聚集诱导发光材料的研究进展及展望

通过超分子自组装构建发光材料是超分子化学研究的重要领域之一.超分子自组装作为一种简单且高效的手段,可以将不同结构的分子通过非共价键作用力构建成具有精确结构和多功能的组装体,进一步赋予了超分子材料独特的物理特性.由于超分子发光材料中非共价键相互作用力具有动态且可逆的性质,因此使其具有对刺激物特异性识别和对微环境变化敏感的特点,从而被广泛应用于生物传感和成像、药物传递、化学传感、人工光收集系统、信息加密和光催化等领域.基于此,为了了解超分子发光材料的最新研究进展,主要按照氢键相互作用、π-π堆积和多种非共价键相互作用,较系统地阐述了最近四年超分子发光材料,从设计到制备再到应用的最新研究进展,并且进一步展望了其未来所面临的挑战.     

Enzymatic activity at the surface of biomaterials via supramolecular anchoring of peptides: the effect of material processing

Supramolecular polymers allow for a modular approach to bioactive biomaterials. Here the effect of processing on the bioactivation of supramolecular biomaterials using a RNase S assay is investigated. Incorporation of S-peptides into supramolecular polymers by solvent casting shows a clear organic-solvent dependency. Although a significant release of the S-peptides is observed, RNase S activity can be measured indicating successful S-peptide surface immobilization. Additionally, the effect of electrospinning on the biomaterial's bioactivity is studied, showing that the fibrous meshes developed were bioactive. The results show the importance of solvent choice, and illustrate the potency of rendering supramolecular biomaterial films and meshes bioactive via a modular approach.     

Remote Chiral Communication in Coadsorber‐Induced Enantioselective 2D Supramolecular Assembly at a Liquid/Solid Interface

Remote chiral communication in 2D supramolecular assembly at a liquid/solid interface was investigated at the molecular level. The stereochemical information in a chiral coadsorber was transmitted over a flexible spacer with a length of up to five methylene groups to a 2D supramolecular assembly of achiral building blocks with the cooperation of specific hydrogen bonding between the chiral coadsorber and achiral building blocks and the confinement effect during 2D crystallization. When the position of the stereogenic center was changed with respect to the stereocontrolling moiety, an odd–even effect was found. A stereogenic center closer to the stereocontrolling moiety transmitted the stereochemical information to the 2D supramolecular assembly more reliably. This result is beneficial not only for mechanistic understanding of chiral communication in 2D supramolecular assembly on surfaces but also for the rational design of homochiral supramolecular assemblies on surfaces.     

Self‐Assembly of Chiral Propeller‐like Supermolecules with Unusual “Sergeants‐and‐Soldiers” and “Majority‐Rules” Effects

Chiral amplification is an interesting phenomenon in supramolecular chemistry mainly observed in complicated systems in which cooperative effect dominate. Herein, chiral, supramolecular, propeller‐like architectures have been constructed through coassembly of an achiral disk‐shaped molecule and chiral amino acid derivatives driven by intermolecular hydrogen bonding. Both the “sergeants‐and‐soldiers” principle and “majority‐rules” effect are applicable in these discrete four‐component supermolecules, which are the simplest supramolecular system ever reported that exhibit chiral amplification.     

Influence of selectivity on the supramolecular polymerization of AB-type polymers capable of Both A x A and A x B interactions

The supramolecular polymerization of two AB-type monomers capable of hydrogen-bond-mediated A x B heterocoupling and A x A homocoupling is discussed. The AB-type supramolecular polymerization is based on the strong interaction between self-dimerizing 2-ureido-pyrimidinone (UPy) and 2,7-diamido-1,8-naphthyridine (NaPy). In an effort to reduce the "self-stoppered" effect that is inherently present in these supramolecular polymerizations we used a novel ureido-pyrimidinone substituted with a dibutylamino group at the pyrimidinone ring. As a result of the substitution, the dimerization constant of the novel UPy unit is lowered compared to the previous UPy unit while the heterodimerization strength is retained. Unexpectedly, the increased selectivity toward heteroassociation not only influences the concentration-dependent degree of polymerization due to reduction of the "self-stoppered" effect but also has a pronounced effect on the ring-chain equilibrium by increasing the tendency to cyclize. In order to quantitatively explain our results, a model was developed that accurately predicts the degree of polymerization by taking into account homo- and heterodimerization as well as cyclization. Finally, molecular weight distributions for noncyclizing AB supramolecular polymerizations with and without a reversible A x A interaction are calculated. It is found that the molecular weight distribution becomes narrower when A x A interactions are present.     

Phase stability of colloidal spheres mixed with supramolecular rod-like polymers

Mixtures of colloids and supramolecular polymers exhibit stimuli-responsive phase behavior. In previous work (Peters and Tuinier, Physica A 510, 233 [2018]) the polymers were treated as fully flexible chains, while in experimental systems supramolecular polymers may have a certain degree of stiffness. Here we predict that for stiff rod-like supramolecular polymers phase separation can occur at much lower polymer concentrations than for flexible supramolecular polymers. Additionally, it is demonstrated that colloid–polymer interactions can significantly influence the equilibrium polymer size distribution, however this does not strongly affect the phase behavior of the mixture. At the low polymer concentrations at which the system already gets unstable, the effect of excluded volume interactions between polymers chains themselves is small. Finally, for an experimental system it is predicted that a variety of re-entrant phase transitions may be observed within a realistic temperature range as illustrated by a specific example.     

Precise Macroscopic Supramolecular Assembly by Combining Spontaneous Locomotion Driven by the Marangoni Effect and Molecular Recognition

Macroscopic supramolecular assembly bridges fundamental research on molecular recognition and the potential applications as bulk supramolecular materials. However, challenges remain to realize stable precise assembly, which is significant for further functions. To handle this issue, the Marangoni effect is applied to achieve spontaneous locomotion of macroscopic building blocks to reach interactive distance, thus contributing to formation of ordered structures. By increasing the density of the building blocks, the driving force for assembly transforms from a hydrophobic–hydrophobic interaction to hydrophilic–hydrophilic interaction, which is favorable for introducing hydrophilic coatings with supramolecular interactive groups on matched surfaces, consequently realizing the fabrication of stable precise macroscopic supramolecular assemblies.     

Recent Progress in Azobenzene-Based Supramolecular Materials and Applications

Azobenzene-containing small molecules and polymers are functional photoswitchable molecules to form supramolecular nanomaterials for various applications. Recently, supramolecular nanomaterials have received enormous attention in material science because of their simple bottom-up synthesis approach, understandable mechanisms and structural features, and batch-to-batch reproducibility. Azobenzene is a light-responsive functional moiety in the molecular design of small molecules and polymers and is used to switch the photophysical properties of supramolecular nanomaterials. Herein, we review the latest literature on supramolecular nano- and micro-materials formed from azobenzene-containing small molecules and polymers through the combinatorial effect of weak molecular interactions. Different classes including complex coacervates, host-guest systems, co-assembled, and self-assembled supramolecular materials, where azobenzene is an essential moiety in small molecules, and photophysical properties are discussed. Afterward, azobenzene-containing polymers-based supramolecular photoresponsive materials formed through the host-guest approach, polymerization-induced self-assembly, and post-polymerization assembly techniques are highlighted. In addition to this, the applications of photoswitchable supramolecular materials in pH sensing, and CO₂ capture are presented. In the end, the conclusion and future perspective of azobenzene-based supramolecular materials for molecular assembly design, and applications are given.     

Highly charged supramolecular oligomers based on the dimerization of corannulene tetraanion

The supramolecular dimerization of tetraanionic corannulene is utilized as a self-assembly motif for the construction of highly charged, buckybowl-based supramolecular oligomers. Oligomers of up to 7 units (3900 g mol(-1)) of reduced dicorannulenic monomers are identified and characterized by various NMR techniques, and the reversibility of their assembly is established through the concentration dependence of their molecular weight and the effect of monofunctional chain-stoppers.     

Supramolecular Polymerization from Controllable Fabrication to Living Polymerization

Supramolecular polymers have attracted plenty of interest in the scientific community; however, developing controllable methods of supramolecular polymerization remains a serious challenge. This article reviews some recent developments of methods for supramolecular polymerization from controllable fabrication to living polymerization. Three facile methods with general applicability for controllable fabrication of supramolecular polymers have been established recently: the first method is a self‐sorting approach by manipulating ring–chain equilibrium based on noncovalent control over rigidity of monomers; the second is covalent polymerization from supramonomers formed by noncovalent interactions; and the third is supramolecular interfacial polymerization. More excitingly, living supramolecular polymerization has been achieved by two elegant strategies, including seeded supramolecular polymerization under pathway complexity control and chain‐growth supramolecular polymerization by metastable monomers. It is anticipated that this review may provide some guidance for precise fabrication of supramolecular polymers, leading to the construction of supramolecular polymeric materials with controllable architectures and functions.     

Finely Controlled Circularly Polarized Luminescence of a Mechano‐Responsive Supramolecular Polymer

Finely controlled circularly polarized luminescence (CPL) supramolecular polymerization based on a tetraphenylethene core with four l ‐ or d ‐alanine branch side chains (l ‐ 1 and d ‐ 1 ) in the solution state is presented, resulting from the tuning of mechanical stimulus. Weak, green emissions of l ‐ 1 and d ‐ 1 in tetrahydrofuran (THF) were converted into strong blue emissions by tuning the mechanical stimulus. The strong blue emissions were caused by an aggregation‐induced emission (AIE) effect during the formation of a supramolecular polymer. Lag time in the supramolecular polymerization was drastically reduced by the mechanical stimulus, which was indicative of the acceleration of the supramolecular polymerization. A significant enhancement of circular dichroism (CD) and CPL signals of l ‐ 1 and d ‐ 1 was observed by tuning the rotational speed of the mechanical stimulus, implying that the chiral supramolecular polymerization was accelerated by the mechanical stimulus.