由功能化穴醚核与六个双金(Ⅰ)配位单元构筑的金属基树形超分子的自组装及发光性质

自组装的金属基树形大分子研究是近年来兴起的新研究方向,迄今,人们大多采用金属离子、有机基团、簇合物等作为金属基树形大分子的生长核心,采用超分子主体穴醚作为生长核心构筑树形大分子的工作还未见报道,我们曾报道了一系列多氮席夫碱穴醚和还原后的八胺穴醚的合成及其性质,     

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。     

大分子自组装成膜技术及膜结构的影响要素

综述了化学吸附,分子沉积,旋涂和接枝成膜等四种大分子自组装成膜技术,并详细介绍了成膜基材,大分子及其溶液性质和温度对大分子自组装膜结构的影响。     

自组装聚酰胺-胺大分子对甲基橙相转移行为的影响

自组装聚酰胺-胺大分子对甲基橙相转移行为的影响;树枝状大分子;聚酰胺-胺;甲基橙;分子自组装     

基于环糊精包结络合作用的大分子自组装

本文综述了基于环糊精包结络合作用的大分子自组装的研究进展,包括：（1) 线型、梳型、多臂星型或超支化聚合物与环糊精或其二聚体自组装形成多聚轮烷（分子项链）、多聚准轮烷、双多聚（准）轮烷、分子管、双分子管、超分子凝胶及其应用;（2）桥联环糊精与桥联客体分子自组装制备线型或超支化超分子聚合物;（3）温度、pH值、光及客体分子刺激响应智能体系; （4) 通过亲水性的环糊精线型均聚物与含金刚烷的疏水性聚合物之间的包结络合作用来制备高分子胶束及其空心球等。     

生物大分子自组装膜及其应用研究进展

本文主要介绍了酶，蛋白质、DNA等生物大分子自组装膜的研究进展，并对生物大分子膜在生物传感器，分子器件，高效催化材料，医用生物材料等方面的应用前景进行了展望。     

小分子级联自组装/解组装策略在精准癌症诊疗中的应用

“智能”识别及靶向癌细胞是精确诊断与高效治疗的关键。目前的策略中,使用小分子共价前体探针（或药物）存在机体代谢速度快及对其他器官毒副作用大的局限;使用纳米探针（或载药）体系则存在分子量不明确、生物穿透性低和易被网状内皮系统捕获等问题。肿瘤“原位自组装”策略兼具了小分子和纳米体系的优点,利用小分子作为前体可提高药物分子在肿瘤组织的生物穿透性,?而自组装形成的纳米结构则提供了更好的生物利用度、更高的代谢稳定性和更长的滞留时间。在此基础上,研究者们通过设计多个肿瘤特异性生物分子顺次激活分子前体,进一步开发了小分子顺次级联自组装/解组装策略,以实现肿瘤组织的精准定位和肿瘤细胞的高选择性。在癌症的诊疗应用中,该策略可有效提高诊断信号的灵敏度,时空追踪癌细胞内的系列动态生物过程,同时实现药物的有效富集,并降低对正常细胞的副作用。该文概述了当前增强型级联自组装、级联自组装/解组装策略的研究进展,为癌症诊疗提供了新见解。     

分子纳米技术与金属有机分子纳米体系

基于超分子自组装的分子纳米技术是一种新兴的高新技术。本文从金属矢量操纵的自组装分子纳米体系、自组装的纳米微反应器与超分子催化和自组装金属超分子高分子纳米材料等三个方面评述了分子纳米技术及其在构筑金属有机分子纳米体系中的发展现状 ,进一步阐述了“金属矢量”的概念 ,并首次提出建立“自组装子工具箱” ,探讨了分子纳米技术的发展方向。     

有机大分子导向无机纳米粒子的分级有序自组装

本文主要综述了基于特定分子设计的有机大分子导向下的无机纳米粒子的分级有序自组装.可以有效导向无机纳米粒子组织的有机大分子主要包括合成大分子和生物大分子,前者如具有氢键识别功能的大分子、聚电解质、嵌段大分子、树枝状大分子;后者如DNA、糖类以及蛋白质.所涉及的无机纳米粒子通常需要通过单层修饰使之与特定的大分子具有识别功能,或者设计表面带有正或负电荷使之与带有负或正电荷的大分子相互识别.该领域的研究在先进功能材料及仿生材料方面具有重要意义.     

LBL自组装技术及自组装生物功能膜结构

主要介绍近几年发展的用于生物大分子自组装功能膜的三种逐层（LBL）自组装技术与制备方法,酰胺化反应自组装技术、生物分子的特异识别自组装技术、分子沉积自组装技术;同时总结了自组装功能膜的结构、特性的表征方法,主要有AFM、TEM、循环伏安法、石英晶体微天平（QCM）技术、UV/VIS、XPS方法等。     

Functional supramolecular assemblies derived from dendritic building blocks

Control of the structure and function of self-assembled materials has been a significant issue in many areas of nanoscience. Among many different types of building blocks, dendritic ones have shown interesting self-assembly behaviour and functional performances due to their unique shape and multiple functionalities. Dendritic building blocks exhibit unique self-assembly behaviour in diverse environments such as aqueous and organic solutions, solid-liquid interfaces, and thermotropic solid conditions. Tuning the balance between hydrophilic and hydrophobic parts, as well as the external conditions for self-assembly, provides unique opportunities for control of supramolecular architectures. Furthermore, the introduction of suitable functional moieties into dendrons enables us to control self-assembly characteristics, allowing nanostructures to exhibit smart performances for electronic or biological applications. The self-assembly characteristics of amphiphilic dendrons under various conditions were investigated to elucidate how dendrons can assemble into nanoscopic structures and how these nanoassemblies exhibit unique properties. Well-defined nanostructures derived from self-assembly of dendrons provide an efficient approach for exhibition of unique functions at the nanoscale. This feature article describes the unique self-assembly characteristics of various types of dendritic building blocks and their potential applications as advanced materials.     

A new approach to heterofunctionalized dendrimers: a versatile triallyl chloride core

A reactive triallyl chloride moiety was prepared as a suitable core for aliphatic polyether dendrons. In addition to allowing access to fourth generation dendrimers, this core contains three alkene functionalities that can be modified after dendrimer formation and used for further dendritic growth.     

Hollow spherical supramolecular dendrimers

The synthesis of a library containing 12 conical dendrons that self-assemble into hollow spherical supramolecular dendrimers is reported. The design principles for this library were accessed by development of a method that allows the identification of hollow spheres, followed by structural and retrostructural analysis of their Pm3n cubic lattice. The first hollow spherical supramolecular dendrimer was made by replacing the tapered dendron, from the previously reported tapered dendritic dipeptide that self-assembled into helical pores, with its constitutional isomeric conical dendron. This strategy generated a conical dendritic dipeptide that self-assembled into a hollow spherical supramolecular dendrimer that self-organizes in a Pm3n cubic lattice. Other examples of hollow spheres were assembled from conical dendrons without a dipeptide at their apex. These are conical dendrons originated from tapered dendrons containing additional benzyl ether groups at their apex. The inner part of the hollow sphere assembled from the dipeptide resembles the path of a spherical helix or loxodrome and, therefore, is chiral. The spheres assembled from other conical dendrons are nonhelical, even when they contain stereocenters on the alkyl groups from their periphery. Functionalization of the apex of the conical dendrons with diethylene glycol allowed the encapsulation of LiOTf and RbOTf in the center of the hollow sphere. These experiments showed that hollow spheres function as supramolecular dendritic capsules and therefore are expected to display functions complementary to those of other related molecular and supramolecular structures.     

Geometric disassembly of dendrimers: dendritic amplification

Geometric disassembly of dendritic structures was realized by a cascade cleavage reaction triggered by an initially stimulated group at the dendrimer core. Release of an exponential number of dendrimer fragments was a result of the branching nature of the cleavage pathway. Evidence for the completion of the disassembly process was provided by the absorbance peak of the p-nitrophenoxide ion that was covalently installed at the periphery of the dendrons for this purpose. The release by dendrimer disassembly of an exponential number of dendrimer fragments that serve to alter the properties of a system is termed dendritic amplification.     

Supramolecular structural diversity among first-generation hybrid dendrimers and twin dendrons

Hybrid dendrimers, obtained by complete monofunctionalization of the peripheral amines of a "zero-generation" polyethyleneimine dendrimer, provide structurally diverse lamellar, columnar, and cubic self-organized lattices that are less readily available from other modified dendritic structures. The reaction of tris(2-aminoethyl)amine (TREN) with 4-dodecyloxybenzimidazolide provides only the corresponding zero-generation TREN dendrimer. From the mixture of tri- and disubstituted TREN derivatives obtained from first-generation self-assembling dendritic imidazolides, the hybrid dendrimer and a twin dendron could be separated, purified, and characterized. The hybrid dendrimers display smectic, columnar hexagonal (Phi(h)), and cubic (Pm_3n) lattices. The TREN twin dendrons, on which only two peripheral amines have been acylated, exhibit centered-rectangular columnar (Phi(r-c)), Phi(h), and Pm_3n lattices. The existence of a thermoreversible Phi(h)-to-Pm_3n phase transition in the first-generation hybrid dendrimers and twin dendrons is exploited to elucidate an epitaxial relationship between the two mesophases. We postulate a mechanism by which the transition proceeds. The thermoreversible Phi(h)-to-Pm_3n phase change is accompanied by optical property changes that are suitable for rudimentary signaling or logic functions. This structural diversity reflects the quasiequivalence of flat-taper and conical self-assembling dendrons and the ability of flexible dendrimers to accommodate concomitant conformational and shape changes.     

Large oligosaccharide-based glycodendrimers

Carbohydrate-based dendritic structures composed of 21 and 27 monosaccharide residues have been synthesized in a convergent manner from trisaccharide building blocks. The oligosaccharide AB2 monomers are based on a maltosyl beta(1-->6)galactose structure, which has been modified to include two methylamino groups at the primary positions of the glucosyl residues. Reductive alkylation of the secondary amino groups, with the innate formyl function of a second oligosaccharide monomer, allows for the chemoselective construction of dendritic wedges, while employing a minimal number of protecting groups. The first-generation dendron can be coupled either to another AB2 monomer, to give a second-generation dendron, or to a tris[2-(methylamino)ethyl]amine-based core moiety, to provide a carbohydrate-based dendrimer. Alternating alpha- and beta-glucosyl residues in the monomers and dendrons, simplifies 1H NMR spectra as a consequence of spreading out the anomeric proton signals. Monomers and dendrons were characterized by extensive one- and two-dimensional NMR spectroscopy in addition to FAB, electrospray, and MALDI-TOF mass spectrometry. Molecular dynamics simulations revealed similar conformations in the dendrons as in the isolated trisaccharide repeating units.     

FeCp]+-induced hexafunctionalization of hexamethylbenzene with dendrons for the direct synthesis of redox-active iron-centered metallodendrimers

Phenol tri- and nonaallyl dendrons (3 and 7, respectively) were functionalized at the focal position to give the new triallyl dendrons 4 and 6 and the nonaallyl dendrons 11 and 13 that contain a iodoalkyl or a bromobenzyl termini. All these dendrons were used for the [FeCp]+-induced hexafunctionalization of hexamethylbenzene in [FeCp(eta6-C6Me6)][PF6] (1) under mild conditions in the presence of KOH. These reactions directly yielded the 18-allyl and 54-allyl dendrimers 9, 10, and 14 with a [FeCp(eta6-arene)]+ unit located at the dendrimer core. Cyclic voltammetry studies were recorded in THF and DMF with these metallodendrimers and compared with those of analogous dendrimers or complexes of smaller size that contain a [FeCp(eta6-arene)]+ unit at the core. The decreased rate of heterogeneous electron transfer when the dendritic size increases first disclosed by Diederich and Gross is confirmed. The variation of the redox potential of the Fe(II/I) redox system with increasing dendritic size is negligible even in a solvent of high dielectric constant such as DMF. This trend is attributed to fact that the involved "redox" orbital is buried on the metal center, well protected by the shell of alkyl chains (electron-reservoir nature), unlike in ferrocene. The chemical irreversibility increases in THF as the dendrimer size increases, due to more facile ligand substitution with THF at the 19-electron level when the chain bulk increases.     

From Random Coil to Extended Nanocylinder: Dendrimer Fragments Shape Polymer Chains

Wedgelike dendrimer fragments , “dendrons”, attached to linear polymers as side groups, can be used to create anisotropic “nanocylinders”, leading to uncoiling and extension of the polymer chains. Synthetic macromolecules of this type can be visualized directly on surfaces and their contour length determined from scanning force micrographs. Unexpected acceleration effects in the polymerization of dendron monomers as well as the structural consequences of dendritic “pieces of cake” (shown schematically) on linear polymer chains are discussed.     

Dendritic supermolecules--towards controllable nanomaterials

Dendritic molecules constitute one of the most exciting areas of modern nanochemistry, largely as a consequence of the unique properties associated with their branched architectures. This article describes how 'dendritic function' can also be achieved using small, synthetically accessible branched building blocks (individual dendrons) which simply self-assemble via non-covalent interactions to generate dendritic nanoscale architectures with novel behaviour. (a) Using non-covalent interactions at the focal point of a dendron allows the self-assembly of nanometre-sized supramolecular dendrimers around an appropriate template species. Such systems have potential applications in the controlled encapsulation and release of active ingredients. (b) Employing non-covalent intermolecular dendron-dendron interactions can give rise to the hierarchical assembly of nanostructured materials. Such assemblies of dendritic molecules ultimately express their molecular scale information on a macroscopic scale, and therefore have applications in materials science, for example as gels. (c) The multiple surface groups of dendrons are capable of forming multiple interactions with large surfaces, such as those found on biomolecules or in biological systems. Employing multivalent interactions between dendron surfaces and biological molecules opens up the potential application of dendritic systems as medicinal therapies. In summary, dendritic supermolecules offer a potentially cost-effective approach to the future application of dendritic systems to a range of real-world problems.     

Liquid-crystalline Janus-type fullerodendrimers displaying tunable smectic-columnar mesomorphism

Janus-type liquid-crystalline fullerodendrimers were synthesized via the 1,3-dipolar cycloaddtition of two mesomorphic dendrons and C60. By assembling poly(aryl ester) dendrons functionalized with cyanobiphenyl groups, displaying lamellar mesomorphism, with poly(benzyl ether) dendrons carrying alkyl chains, which display columnar mesomorphism, we could tailor by design the liquid-crystalline properties of the title compounds as a function of each dendron size. The liquid-crystalline properties were examined by polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction. Depending on the dendrimer generations, smectic (SmC and/or SmA phases) or columnar (Colr-c2mm or Colr-p2gg phases) mesomorphism was obtained. The supramolecular organization is governed by (1) the adequacy of the cross-sectional area of the dendrons, (2) the microsegregation of the dendrimer, (3) the deformation of the dendritic core, and (4) the dipolar interactions between the cyanobiphenyl groups. Comparison of the mesomorphic properties of two fullerodendrimers with those of model compounds (fullerene-free analogues) indicated that the C60 unit does not influence the type of mesophase that is formed. Molecular properties determined in solution (permanent dipole moment, specific dielectric polarization, molar Kerr constant) confirm that microsegregation persists in solution and strengthen the models proposed for the structure of the mesophases.