超分子科学中的仿生自组装

仿生自组装是分子自组装与生命科学相交叉的一个新的研究领域.本文强调了开展仿生自组装研究的意义.介绍了目前仿生自组装的研究进展,并举例进行了说明,最后探讨了仿生自组装领域的未来发展方向.     

酶催化超分子自组装及其在癌症诊疗中的应用研究进展

自组装是自然界的普遍现象,也是构建超分子生物材料的有力工具。在众多方法中,酶催化超分子自组装具有优异的肿瘤靶向性及良好的生物安全性,是近年来癌症诊疗的一个重要新方向。针对这一趋势,本文简介了酶催化超分子自组装在细胞内、外的构建方法,详细总结了其在癌症诊疗中的应用。研究表明,酶催化超分子自组装材料在生物医学成像、选择性杀死癌细胞、药物递送和克服药物不良反应方面具有潜在的应用价值。提出了体内超分子组装体的微观形貌需要明确表征、构建自组装方法的酶范围需要扩展以及需要探索酶催化超分子自组装（EISA）与亚细胞器的相互作用等解决其发展中的问题的思路和方向,并对其在抗菌药物开发、免疫调节、创伤修复和组织再生领域的潜在应用作出了展望。     

吡唑类配体在超分子自组装中的应用

吡唑类配体是一类多功能有机配体,详细介绍了单吡唑、双吡唑和多吡唑配体在超分子自组装分子中的发展现状,探讨了其发展方向。     

环糊精的超分子组装及应用新进展

简要介绍了环糊精的结构特征及用途,详细综述了环糊精的超分子组装及纳米超分子的构筑;环糊精空腔的超分子识别功能;新型环糊精衍生物的合成及在分析化学中的应用。     

小分子离子自组装制备功能超分子材料

离子自组装是合成功能超分子材料的有力途径,而带相反电荷的小分子离子之间的离子自组装由于具有良好的结构可设计性和功能可调节性,是离子自组装制备功能超分子材料领域的研究热点。本文首先对离子自组装的特点进行了简单的介绍,然后分3类对小分子离子自组装制备功能超分子材料领域进行了综述,主要包括染料与表面活性剂自组装制备功能材料,平面刚性离子自组装制备功能材料以及多金属酸盐离子自组装制备功能材料。目前,小分子离子自组装在组装单元的选择以及材料功能扩展角度已取得了长足的进步,但如何实现利用小分子离子自组装从微观结构到宏观材料的跨度,制备出能在实际生产中应用的功能超分子材料,还有待进一步发展。     

Fabrication of polymer antireflective coatings by self-assembly of supramolecular block copolymer

We demonstrated a method of fabricating antireflective coatings based on the self-assembly of supramolecular block copolymer formed by polystyrene terminated with carboxyl (PS-COOH) and poly(methyl methacrylate) terminated with amine (PMMA-NH₂) via hydrogen bonding. Different porous films were generated by selectively removing PS-COOH from the spin-coated films with a selective solvent, cyclohexane, under different conditions. The refractive index of such porous film can be tuned from 1.49 down to 1.26 by controlling the thickness of the porous film. For the porous layer with n ˜ 1.26, the light transmittance of the glass about 97.93% was achieved in the visible range (λ ˜ 574 nm). By varying the solution concentration and exposing time in cyclohexane, inhomogeneous three-layered porous films were generated: top and bottom layers with high porosities and the middle layers with lower porosities, respectively. The light transmittance of the glass coated with this inhomogeneous film was about 98.00% in the near-infrared region corresponding to wavelength between 800 and 1400 nm. The wavelength region of the broadband antireflective films with high transmittance more than 99.00% can be fine tuned to 1200-2000 nm with increasing the film thickness.     

Self-healing supramolecular waterborne polyurethane dispersions with quadruple hydrogen bonds in main chain

A facile method for preparing supramolecular waterborne polyurethane (WPU) based on quadruple hydrogen bonds (4H-WPU) is reported. Herein, 4H-WPU with quadruple hydrogen bonds in main chain were synthesized by poly (1,4-buthylene-neopentylene adipate glycol) as soft segment, 2-ureido-4[1H]-pyrimidinone (UPy) functionalized monomer, isophorone diisocyanate, 2,2-Bis(hydroxymethyl)propionic acid (hydrophilic monomer), isophorondiamine, triethylamine (neutralizer), and monoethanolamine (blocking agent) as hard segment. The molecular weight of 4H-WPU was controlled around 18,000 consistently. The properties of 4H-WPU with different content of hydrophilic group, hard segment, and UPy units were characterized and the results could provide the reference for preparing supramolecular WPU with high mechanical and self-healing performance while maintaining dispersion stability. The tensile strength of 4H-WPU was 10 times of the blank sample. The healing time of scratched 4H-WPU film was inversely proportional to the content of UPy- functionalized monomer and the shortest healing time is 2.5 hr at 80°C. Mechanical performance of healed films can be restored to more than 90%.     

On the phase behaviour of organic semiconductors

The physical organisation, from the molecular to the macroscale, of functional organic matter such as polymer semiconductors can profoundly affect the properties and features of the resulting architectures and their consequent performance when used as active layers in organic optoelectronic devices, including organic thin‐film field‐effect transistors, organic light‐emitting diodes or organic photovoltaic cells. Here, we present a survey on the principles of structure development from the liquid phase of this interesting and broad class of materials with focus on how to manipulate their phase transformations and solid‐state order to tailor and manipulate the final ‘morphology’ towards technological and practical applications. Copyright © 2012 Society of Chemical Industry     

Formation of 2D supramolecular architectures at electrochemical solid/liquid interfaces

The controlled formation of supramolecular architectures on chloride pre-covered Cu(1 0 0) has been studied by means of in situ scanning tunneling microscopy (STM) in an electrochemical environment. On top of the c(2 × 2)-Cl layer, ordered arrays of supramolecular cavitand structures could be obtained either by a surface assisted assembly of monomer building-blocks (1,1′-dibenzyl-4,4′-bipyridinium molecules) or by a direct adsorption of supramolecular assemblies (metallo-supramolecular squares) from the solution phase. Besides the omnipresent van-der-Waals-like interactions additional electrostatic interactions between the anionic chloride layer and the positively charged (metallo)-organic molecules are supposed to have strong impact on the 2D phase behavior in both cases.The obtained supramolecular entities with their cavities oriented towards the solution phase can be regarded as potential host assemblies for the specific inclusion of guest molecules.     

Schottky-structured 0D/2D composites via electrostatic self-assembly for efficient photocatalytic hydrogen evolution

Semiconductor-metal heterostructure, especially represented by various inorganic semiconductors-platinum (Pt) hybrids, is widely applied in converting solar power to chemical energy. Given the scarcity of Pt and the availability of coupling, the development of a non-Pt regimen and facile assembly strategy is critical. In this study, Cd_xZn_1-xS/Ti₃C₂ ultrathin MXene composites were availably prepared with a facile electrostatic assembly strategy. The unique 0D/2D assembly demonstrated remarkably enhanced performance toward photocatalytic hydrogen production compared with bare Cd_xZn_1-xS. Spectroscopic characterization analysis and band theory discussion substantiated the effects of electronic interaction and the Schottky barrier arising from intimate contact of Cd_xZn_1-xS and Ti₃C₂ MXene on the swift separation of photoinduced electron-hole pairs. Successful application of electrostatic self-assembled Cd_xZn_1-xS with ultrathin MXene opens a new area of utilizing electrical difference and band theory to prepare rational semiconductor/MXene Schottky structure towards various photocatalytic reactions.     

Binding of organic anions by synthetic supramolecular metallopores with internal Mg2+-aspartate complexes

We report that cation-selective transmembrane pores formed by synthetic p-octiphenyl beta barrels with internal aspartate residues can be transformed into anion-permeable metallopores with internal Mg(2+)-aspartate complexes. These metallopores are shown to be useful for fluorimetric sensing of a broad variety of organic anions of biological relevance such as phytate, heparin, thiamine phosphates, and adenosine triphosphate. The negligible flippase activity measurable for Mg(2+)-free pores indicates that transmembrane p-octiphenyl beta barrels do not disturb the lipid bilayer suprastructure, in other words, they form barrel-stave rather than toroidal pores.     

Tuning intermolecular non-covalent interactions for nanowires of organic semiconductors

Anthracene and its derivatives are used to demonstrate a simple way to cast assemble nanowires of organic semiconductors with tuning of intermolecular non-covalent interactions by molecular design. The tuning of intermolecular interactions could be achieved by (i) decreasing intermolecular hydrophobic interactions by linking hydrophilic side chains to anthracene rings, (ii) increasing intermolecular interaction for self-assembly with the assistance of hydrogen bonds, and (iii) enhancing molecular π-π interaction by increasing the conjugated dimension of the compounds.     

Evolution of organic oxygen bonds during pyrolysis of coal

Five Czech coals of different rank (70.2, 71.5, 74.5, 75.0 and 83.3 wt% carbon) were heated at different temperatures in the range 250–850 °C and the contents of oxygen-containing functional groups (OH, COOH, CO, OCH₃) were determined in the coals and carbonization residues. The coals and residues were subjected to pyrolysis chromatography at 740 °C and the yields of phenol produced were measured. The dependence of the oxygen functions and the phenol yield on temperature and coal rank is discussed. In the coals studied, the most resistant oxygen groups appear to be hydroxyl and methoxyl; carboxyl and carbonyl oxygen are eliminated below 550 °C.     

新型超分子化合物的合成选择性识别及应用研究新进展

介绍了新型超分子化合物的合成,新型超分子化合物的合成及对阴离子的识别,新型超分子化合物的合成及应用研究。     

Shuttle-like supramolecular nanostructures formed by self-assembly of a porphyrin via an oil/water system

In this paper, in terms of the concentration of an aqueous solution of a surfactant, we investigate the self-assembly behavior of a porphyrin, 5, 10, 15, 20-tetra(4-pyridyl)-21H, 23H-porphine [H2TPyP], by using an oil/water system as the medium. We find that when a chloroform solution of H2TPyP is dropwise added into an aqueous solution of cetyltrimethylammonium bromide [CTAB] with a lower concentration, a large amount of irregular nanoarchitectures, together with a small amount of well-defined shuttle-like nanostructures, hollow nanospheres, and nanotubes, could be produced. While a moderate amount of shuttle-like nanostructures accompanied by a few irregular nanoarchitectures, solid nanospheres, and nanorods are produced when a CTAB aqueous solution in moderate concentration is employed, in contrast, a great quantity of shuttle-like nanostructures together with a negligible amount of solid nanospheres, nanofibers, and irregular nanostructures are manufactured when a high-concentration CTAB aqueous solution is involved. An explanation on the basis of the molecular geometry of H2TPyP and in terms of the intermolecular π-π interactions between H2TPyP units, and hydrophobic interactions between CTAB and H2TPyP has been proposed. The investigation gives deep insights into the self-assembly behavior of porphyrins in an oil/water system and provides important clues concerning the design of appropriate porphyrins when related subjects are addressed. Our investigation suggests that an oil/aqueous system might be an efficient medium for producing unique organic-based nanostructures.     

Temporary organic bonds in the production of ceramics (review)

Translated from Steklo i Keramika, No. 3, pp. 20–22, March, 1989.     

Electrostatic self-assembly of 2D-2D CoP/ZnIn2S4 nanosheets for efficient photocatalytic hydrogen evolution

Constructing efficient and cost-effective photocatalysts are highly desirable for photocatalytic hydrogen evolution. Herein, we prepare a unique 2D-2D architecture photocatalyst composed of CoP and ZnIn₂S₄ (ZIS) nanosheets through electrostatic self-assembly method. The constructed 2D-2D CoP/ZIS exhibit a remarkably enhanced photocatalytic performance with hydrogen production rate of 8.775 mmol g⁻¹ h⁻¹, and this value is much higher than ZIS and most of other ZIS-based nanohybrids. Additionally, the nanohybrids possess excellent stability with 96.3% of initial activity remaining after 24 hours of testing. These satisfactory results are attributed to the large/intimate contact interface and the photo/electro-chemical properties of ZIS and CoP, which improves light absorption, facilitates photoelectron transport and suppresses charge recombination. This work not only demonstrates ZIS nanosheet can serve as a versatile and effective platform supporting non-noble metal nanosheets to boost their photocatalytic performance, but also offers a general and simple electrostatic self-assembly method to design 2D-2D-based heterostructures for hydrogen conversion from water splitting.     

Mixing of a self-assembled supramolecular polymer and a covalent polymer in organic solutions

We report on a neutron scattering study of the molecular structure of a self-assembled supramolecular polymer composed of a bicopper complex within a solution of a covalent polymer (atactic polystyrene/trans-decalin). The study is achieved by putting two binary phases in contact and allowing for diffusion of both components in either phase. It is shown that the one-dimensional bicopper filaments are compatible to a high extent with the atactic polymer. These results are discussed in the light of a recently devised encapsulation process of the bicopper filaments within the fibrils of a physical network of isotactic polystyrene.