Chiral liquid crystals based on pillararene and supramolecular self-assembly-induced chirality amplification

Macrocyclic liquid crystals combine the unique property of liquid crystals and excellent supramolecular assembly ability of macrocyclic compounds.It is a significant challenge to make rational use of the advantages of macrocyclic compounds to prepare new macrocyclic mesogens.Pillararenes,a type of macrocycles with rigid pillar-shaped frameworks and easy-tofunctionalize property,are excellent building blocks to fabricate liquid crystal materials.However,the site-selective modification property of pillararene has been rarely exploited to tailor liquid crystal behaviors.Previously reported pillararene-based liquid crystal systems are almost prepared by per-functionalized pillararenes.Herein,we report the regulation of chiral liquid crystal behaviors by different derivatization of pillararene.Lyotropic and thermotropic liquid crystals with different chirality were obtained by self-assembly of pillararene with different numbers of cholesterol groups.The bridge between thermotropic liquid crystal and lyotropic liquid crystal based on pillararene is built.In addition,the chirality of the mesogens can be amplified through supramolecular self-assembly driven by noncovalent interactions.Based on the different liquid crystal behaviors,the optical signal of the pillararene-based chiral liquid crystals was used to fabricate an information encryption system.This work provides a simple strategy to regulate liquid crystal behaviors via pillararene-based mesogens and realizes information encryption through the combination of different types of liquid crystals.

A clusteroluminescent supramolecular polymer network constructed by pillararene and its application in information encryption

Clusterization-triggered emissive(CTE)materials have attracted great attention in recent years.The regulation of the emission property of materials with CTE property through supramolecular interactions is an excellent strategy for the construction of smartfluorescent materials.In this work,we have pre-pared a regulatable supramolecular polymer network with CTE properties through pillararene-based host-guest interactions.The pillar[5]arene-grafted poly(methyl methacrylate)(PMMA)showed a classic CTE character.After adding Brooker’s merocyanine-grafted polymer to the solution of the pillar[5]arene-containing PMMA,the supramolecular polymer network gel formed by the host-guest inter-actions between pillararene and Brooker’s merocyanine guest.This supramolecular network showed brighterfluorescence than the pillar[5]arene-grafted PMMA in the solid state.In addition,thefluorescence emission of the supramolecular network can be further regulated by pH conditions.After adding an acid,the Brooker’s merocyanine-containing guest polymer was protonated,and the supramolecular net-work changed to a protonated network through host-guest interactions between protonated Brooker’s merocyanine guest and pillararene.Interestingly,thefluores-cence was quenched when the supramolecular network turned into the protonated network.After adding a base,the protonated network can convert back to the origi-nal network,along with recovery of thefluorescence.Therefore,the regulation of thefluorescence of the supramolecular polymer materials with CTE was successfully realized by pillararene-based host-guest interactions.Furthermore,this tailorablefluorescent supramolecular polymer network system was applied as an information encryption material.

聚己内酯基准聚轮烷的构建技术

准聚轮烷作为一种新型超分子体系,已被广泛应用于生物传感器、分子机器及药物控释载体等诸多领域。本文首先简要介绍了聚己内酯(PCL)基准聚轮烷的研究意义,然后基于不同的环状主体对PCL基准聚轮烷的构建技术进行了分类和举例介绍,最后对PCL基准聚轮烷的发展前景进行了展望。本文工作可为功能性超分子聚合物的研究提供借鉴。

Pillararene-based supramolecular systems for theranostics and bioapplications

As an emerging type of important macrocycles for supramolecular chemistry,pillararenes and their derivatives have been widely studied and applied in numerous fields,which intensively promotes the development of chemistry,materials science and biology.Pillararene-based theranostic systems are of special interest in the biological and medical areas as they have shown very promising results.Owing to easy preparation,reliable guest affinity,good biocompatibility and stability,pillararenes are frequently used to construct functional biomaterials.On one hand,pillararenes can either be used individually or form diversiform self-assemblies such as micelles,nanoparticles and vesicles to increase water solubility and biocompatibility of drugs.On the other hand,it is promising to modify solid materials like framework materials,silica nanoparticles and graphene oxides with pillararene derivatives to enhance their functions and controllability.In this review,we summarize recent endeavors of pillararene-based supramolecular systems with theranostics and other biological applications comprising drug delivery/chemotherapy,photodynamic/photothermal therapy,antimicrobials,bioimaging,etc.By introducing several typical examples,the design principles,preparation strategies,identifications and bio-applications of these pillararene-based supramolecular systems are described.Future challenges and directions of this field are also outlined.

Calixarene/pillararene-based supramolecular selective binding and molecular assembly

Calixarenes and pillararenes are cyclic oligomers containing repeating units of phenol and methane. The modification of ionized groups bring calixarenes and pillararenes derivates both good water solubility and strong binding affinities towards various organic/inorganic/biological guest molecules in both water and the solid state. Meanwhile, the pre-organized structures of these compounds are indispensable in constructing of stimuli-responsive supramolecular assembly. With these properties, the supramolecular selective binding and molecular assembly based on calixarene/pillararene are widely used in enzyme tandem assay, stimuli-responsive nanostructure, drug delivery, organelle fluorescent imaging, photo-controlled morphological change, organic and inorganic hybrid material, solid tunable photo-luminescence and so on. This review summarized the recent research progresses on the calixarene/pillararene-based supramolecular systems and discussed the expectation of the future development.

Pillararene/Calixarene-based systems for battery and supercapacitor applications

Pillararene/calixarene-based functional materials have garnered significant attention for their unique topological/chemical structures and physicochemical properties,and their extended applications in electro-chemistry have given rise to a promising area of research.This review details current advance in developing electrochemical energy materials based on pillararene/calixarene systems from the viewpoint of both fundamental theoretical simulations and research on practical applications.First,we discuss the underlying mechanisms of applying pillararene/calixarene-based systems for electrochemical energy applications.Second,we summarize simulation studies on pillarquinone and calixquinone with intrinsic structures for applications in batteries.In addition,state-of-the-art applications of pillararene/calixarene-based systems in electrochemical energy storage devices such as lithium/sodium-ion batteries and supercapacitors are highlighted.The diverse roles they play and the various design strategies that have been investigated for high-performance pillararene/calixarene-based batteries are analyzed.Finally,we discuss the prospects for further developments in this emerging field.This review not only describes recent advances in pillararene/calixarene-based batteries and supercapacitors but also lays a firm groundwork for their further application in electrochemical energy engineering.

The emerging applications of pillararene architectures in supramolecular catalysis

Over the last decade,numerous research efforts have been devoted to pillar[n]arenes since their debut.The popularity of pillararenes is a reflection of current research trend in supramolecular and macrocyclic chemistry in general.Among the vast applications(such as chemosensors,drug delivery,transmembrance channels,and separation)of pillararenes,their utilization in catalysis is a relatively less explored area.However,soaring attention has been paid by researchers in recent years and this field has seen gradual increasing publications.Therefore,in this review we will discuss progress in the emerging applications of pillararene architectures in catalysis based on various reaction genre including reduction,oxidation,coupling,decomposition and others.Furthermore,this review not only focuses on the pillararenes based current progress in catalysis,but also provides the signs for future development in this research field.

Enhanced photocatalytic hydrogen production performance of pillararene-doped mesoporous TiO_(2) with extended visible-light response

Pillararenes are a new type of supramolecular hosts,and they have been widely applied in drug delivery,catalysis,separation process,and sensors.However,they have rarely been used to produce hydrogen.Here,we report that pillararenes were used as functional molecules to explore photocatalysts and efficiently promoted hydrogen production from water.The most common and easily synthesized pdimethoxy pillar[5]arene(PI-OMe) was employed to form an organic-inorganic hybrid material with titanium dioxide(TiO_(2)),denoted as PI-OMe-TiO_(2).using a convenient sol-gel method.When the material was loaded with Pt nanoparticles,the resulting Pt/PI-OMe-TiO_(2)had a good activity and stability in catalyzing water splitting to produce hydrogen under visible light.The optimized catalyst Pt/PI-OMe-TiO_(2)(5.2 wt%)had a photocatalytic hydrogen production rate of 1736 μmol g^(-1)h^(-1) under visible light(λ> 420 nm)irradiation.The catalyst with a Pt loading of 0.5 wt% and a PI-OMe content of 5.2 wt% also showed good long-term durability after 10 cycles of 50 h testing.The total amount of hydrogen produced was65.01 mmol/g,and the corresponding turnover number(TON) value was 2084.Our findings suggest that pillararene derivatives are promising functional molecules to make efficient and stable hybrid photocatalysts with TiO_(2)and open a new door to hydrogen production using visible light.

Tailoring two-dimensional surfaces with pillararenes based host-guest chemistry

The two-dimensional surfaces have been fueled by the infinite possibility they offe red fo r basic re search,and for novel technologies in nanoelectronics.To realize many of these promises,the effective strategies were to design and control their surface chemistry,which plays a vital role in determining the chemical and physical properties.Macrocyclic host-guest chemistry with the reversible noncovalent interactions between macrocyclic hosts and suitable guests can be readily used for constructing multifunctional surfaces.Macrocyclic pillararenes,possessed the unique structure,have attracted the attentions of researchers in recent years.This feature article covers the recent development of pillararene-based twodimensional inte rfaces,including the fabrication and function of the hybrid composite.The combination of pillararenes and materials platform exhibited the novel property because of the characte ristic of cavity of macrocyclic host and confined spaces of surfaces.We anticipate that this review will be helpful to the researchers working in the fields of supramolecular chemistry and materials science.

手性联萘酚功能化柱[5]芳烃的合成及手性识别

设计合成了手性联萘酚(BINOL)功能化的柱[5]芳烃3-R/S和6-R/S,通过核磁和质谱表征化合物结构。经HPLC拆分6-R获得非对映异构体6-RR p和6-RS p,进一步通过紫外滴定法测定6-RR p和6-RS p对R/S-1-苯乙醇和R/S-1-苯乙胺的结合常数,以探究手性联萘酚功能化的柱[5]芳烃对手性分子的选择性识别能力。结果表明,在柱[5]芳烃的一个苯环单元两侧修饰上大位阻基团能够阻止其翻转,通过手性HPLC拆分可获得具有手性的柱[5]芳烃非对映异构体。其中非对映体6-RR p对S-1-苯乙醇和R-1-苯乙醇的结合常数分别为1.2×10^(4)、2.6×10^(3) M-1,K s/K R=4.6,可选择性识别S-1-苯乙醇和R-1-苯乙醇。

Pillararene-based fluorescent sensors for the tracking of organic compounds

Fluorescent chemosensors based on pillararene complexes represent a new, promising branch in sensor technology. Because of CH-π interactions, aliphatic chains are well suited for the columnar cavities of pillararenes and bulky or sheet-like(sub)structures can be arranged on the portals. Thus, pillararenes form versatile receptors and an alteration of the fluorescence behavior upon complexation ensures the function of these chemosensors as the reporter. Although this field of research exists only since a few years, remarkable chemosensors were developed for substances as diverse as medical drugs,biochemicals, herbicides and explosives.

Icing on the cake: combining a dual PEG-functionalized pillararene and an A-D-A small molecule photosensitizer for multimodal phototherapy

The design of photosensitizers with multimodal antitumor activity and the construction of nanocarriers with specific targeting are two magic weapons to achieve highly efficient tumor phototherapy. Here we developed an A-D-A fused-ring conjugated small molecule photosensitizer DPIC and proposed a new strategy of constructing phototherapy agents, namely using supramolecular vesicles constructed by the self-assembly of a novel dual PEG-functionalized pillararene WP5-2 PEG to load DPIC. These new nanocarriers had excellent water solubility and drug encapsulation rates. The prepared DPIC NPs had a better water solubility compared with DPIC molecules and had a uniform hollow spherical morphology, which is beneficial for cell endocytosis. Under laser irradiation(808 nm), the DPIC NPs had a photothermal conversion efficiency(PTCE) of 55% and a PTCE of 49% under980-nm laser irradiation. The DPIC NPs also displayed dual type I and type II photodynamic activity. DPIC NPs had superior biocompatibility and stability and can also inhibit tumor growth in vitro and in vivo, demonstrating their potential for highly efficient cancer phototherapy.

光响应性准聚轮烷薄膜的制备实验设计

准聚轮烷以其独特的艺术美学拓扑结构和优异性能,引起了材料学家极大的研究兴趣。该文对基于准聚轮烷制备具有光响应性薄膜的实验进行了探索。首先利用柱[5]芳烃和聚亚甲基的主客体络合,构建了偶氮苯衍生化柱[5]芳烃(P5-Azo)和聚亚甲基嵌段聚苯乙烯(PM-b-PS)的准聚轮烷;然后采用呼吸图法,通过制膜条件的优化,分别在水汽氛围和乙醇氛围下制备出准聚轮烷多孔薄膜和微球薄膜;最后研究了准聚轮烷薄膜紫外光照射前后润湿性的变化。

基于柱芳烃主客体相互作用和卤键构筑超分子聚合物网络及其应用研究

合成了基于柱[5]芳烃主体和4-4-(溴苯基)吡啶客体的AB型单体,该单体可在氯仿中自组装成线形超分子聚合物。加入4,4′-联吡啶(BPy)后,在卤键的作用下,线形超分子聚合物发生交联,形成超分子聚合物网络(SPN)。这种超分子聚合物网络对于甲基橙具有高吸附能力,显示了其在废液处理中的潜力。

基于柱芳烃的超分子催化研究进展

利用超分子识别与组装的基本原理,发展新型超分子催化剂以实现催化反应的超分子选择性调控是当今催化领域研究的热点和前沿。柱芳烃是一类具有刚性骨架结构的新型大环主体分子,其富电子的空腔和优异的主客体化学性质能够对客体分子进行选择性识别,使其在超分子催化中显示了独特的催化性能。综述了近十年来柱芳烃在超分子催化领域的应用研究进展,重点阐述主-客体相互作用对超分子催化选择性的调控作用,并对其存在问题进行总结及发展前景进行展望。

基于柱芳烃及其配体的抗生素缓释体系制备

脂质体能够作为药物载体,具有疏水特性的柱芳烃和配体分子自发嵌入到磷脂双分子层膜后可构建抗生素缓释体系。实验结果表明,包载在脂质体内部的抗生素能够通过柱芳烃通道向外释放,在1800 s时,释放率可以达到99.51%。配体分子在与柱芳烃结合后会阻塞柱芳烃通道,阻碍抗生素向外释放,当配体分子和柱芳烃配比为1∶1时,脂质体内部抗生素释放速率几乎趋近于0。

柱芳烃在阳离子识别中应用的研究进展

较系统地综述了柱芳烃的合成发展过程及其对阳离子识别的研究进展情况,指出了柱芳烃是一类新型超分子主体大环化合物,拥有高度对称和刚性的骨架结构,并且具有易于修饰和功能化的特点,可高效地识别有机阳离子和金属阳离子。最后,简单展望了柱芳烃识别阳离子的应用前景。

新型大环主体化合物柱芳烃的合成及应用

介绍了柱芳烃的产生、发展、应用及结构特征,详细综述了:新型柱芳烃的合成与性能研究;新型柱芳烃的超分子自组装及应用;新型柱芳烃的合成及在医药中的应用。并对柱芳烃的发展进行了展望。

柱芳烃与离子液体络合体系的研究进展

柱芳烃具有独特的富电子空腔和易于功能化的特性,在材料科学、生命科学、环境科学等领域呈现出良好的应用前景.将离子液体与柱芳烃结合可以在离子液体的可设计性结构、无饱和蒸气压、可重复使用等特点的基础上进一步提高其应用性能.介绍了温敏型、pH值型、光敏型柱芳烃与离子液体主客体络合体系的研究成果,总结了近几年柱芳烃与离子液体络合体系的发展趋势,并对络合体系在催化领域的应用前景进行了展望.

多晶X射线衍射技术在准聚轮烷研究中的应用

X射线衍射技术是利用X射线在结晶材料中产生的衍射效应来进行材料晶相结构分析的一种无损检测技术。本文利用多晶X射线衍射技术研究在不同条件下制备的准聚轮烷材料固态晶相结构的变化。首先,基于聚ε-己内酯(PCL)和1,4-二乙基柱[5]芳烃(DEP5A),通过改变柱[5]芳烃的摩尔比、溶剂和PCL的分子量等实验条件,构建了具有不同固态晶相结构准聚轮烷;然后,对比分析了不同制备条件对准聚轮烷材料的晶相结构的影响;最后,得出构建准聚轮烷材料的最佳实验条件。本文的研究工作为新型超分子聚合物材料的研究和开发提供借鉴。