Mechanism of N-octadecyl-N′-maleoyl-L-phenylalanine self-assembled into supramolecular structures

N-Octadecyl-N1-maleoyl-L-phenylalanine （ODMA-L-Phe） was synthesized through the condensation, deprotection and acid- ylation reaction of BOC-L-phenylalanine, octadecylamine and maleic anhydride. ODMA-L-Phe can self-assemble in some organic solvents and turned them into thermally reversible physical supramolecular organogels. The morphology of ODMA-L-Phe aggregates was characterized by polarized optical microscopy （POM） and field emission scanning electron microscope （FE-SEM）. The aggregates of ODMA-L-Phe were needle-like fibrils with diameters of approximately 100-200 nm. The mechanism of ODMA- L-Phe self-assembly in organic solvents was investigated using XH NMR and circular dichroism （CD）. The results indicated that hydrogen bonding was one of the main driving forces for the self-assembly of ODMA-L-Phe.

Lignin-assisted construction of sub-10 nm supramolecular self-assembly for photothermal immunotherapy and potentiating anti-PD-1 therapy against primary and distant breast tumors

Photothermal therapy(PTT)has brought hope for cancer treatments,with hyperthermia-induced immunogenic cell death(ICD),which is a critical part of therapeutically induced antitumor immune responses.Limited immune stimulation response in PTT is the primary reason for incomplete tumor ablation,therefore demonstrating urgent requirements for ICD amplifier.Herein,a sub-10 nm supramolecular nanoassembly was formed by coassembly of clinically approved aluminum adjuvant and commonly used indocyanine green(ICG)under the assistance of lignosulfonate(LS,a green and sustainable multifunctional lignin derivative)for localized photothermal-immunotherapy of breast cancer.The overall results revealed that LS-Al-ICG is capable of inducing amplified ICD,efficiently eliciting solid immune responses through dendritic cells(DCs)activation and cytotoxic T-cell responses initiation for tumor killing.Moreover,anti-PD-1 therapy blocked the PD-1 pathway and led to remarkable anti-tumor efficacy against laser-irradiated primary tumors and distant tumors by potentiating systemic tumor specific T cell immunity.The results of this study demonstrate a handy and extensible approach for engineering green natural lignin nanoparticles for cancer immunotherapy,which shows promise for delivering other therapeutics in biomedical applications.

Supramolecular Self-assembly and Functionalization of Porphyrin-based Systems

Porphyrins are abundant in nature. They have been frequently employed as building blocks in the construction of nanoarchitectures and functional supramolecular systems. Recently, a series of novel porphyrin molecules including small molecules and polymers have been originally designed and synthesized with the aim of producing nanostructures with controllable-growth and materials with high-performance. Literature coverage is through 2004-2012. This review gives a full summary of related studies in our group.

自组装超分子前驱体制备g-C_(3)N_(4)及其光催化分解水产氢的研究

光催化剂的结构调控对提高光催化效率有重要意义。以三聚氰胺为原料制备了g-C_(3)N_(4),并以三聚氰胺-三聚氰酸超分子为前驱体,制备了一系列MCx-g-C_(3)N_(4)(x为三聚氰胺与三聚氰酸的物质的量比,x=1、2、3或4)。采用XRD、FT-IR、SEM、TEM、N_(2)吸/脱附和XPS等对g-C_(3)N_(4)和MCx-g-C_(3)N_(4)进行了表征,发现g-C_(3)N_(4)和MCx-g-C_(3)N_(4)具有不同的形貌、结构、组成和比表面积。其中,MC3-g-C_(3)N_(4)为多孔的纳米片结构,n(C元素):n(N元素)为1.23,比表面积为45.63 m^(2)/g,是g-C_(3)N_(4)比表面积的4.5倍。以Pt为助催化剂,三乙醇胺为牺牲剂,在可见光下(≥400 nm)考察了催化剂的光催化分解水产氢性能。结果表明,MC3-g-C_(3)N_(4)表现出最佳的光催化分解水产氢性能,其产氢速率达到1127.83μmol/(h·g),是g-C_(3)N_(4)的35倍。MC3-g-C_(3)N_(4)较大的比表面积和多孔结构为反应提供了更多的活性位点,且纳米片结构缩短了光生电子迁移到催化剂表面的距离,促进了光生电子和空穴的分离,从而显著提高了其光催化分解水产氢性能。

Enhancing the Circularly Polarized Luminescence of Self-assembled Cyanostilbenes through Extended π-Conjugation

Chiral supramolecular assembly of π-conjugated luminophores provides a promising avenue for enhancing circularly polarized luminescence.In this study,we shed light on the impact of π-conjugation length on circularly polarized luminescent performance of the resulting supramolecular assemblies,by designing a tetra-cyanostilbene monomeric compound alongside two dicyanostilbene control compounds.These cyanostilbene-based compounds possess the ability to form chiral supramolecular polymers in toluene,driven by a synergistic combination of intermolecular hydrogen bonding and π-stacking interactions.The extended π π-aromatic skeleton brings bathochromic-shifted fluorescence and enhanced intermolecular stacking capability for the tetra-cyanostilbene compound.Consequently,chiral supramolecular assemblies formed by the tetra-cyanostilbene compound demonstrate a remarkable two-fold increase in g_(lum) values relative to the assemblies formed by the dicyanostilbene compounds.Overall,this study provides valuable insights into the relationship between-conjugation length and the circularly polarized luminescent performance of π-conjugatedsupramolecularassemblies.

Differentiated self-assembly through orthogonal noncovalent interactions towards the synthesis of two-dimensional woven supramolecular polymers

Molecular weaving is a powerful approach to make molecularly woven materials that have showed unprecedented characteristics and properties intrinsically distinct to those of non-woven materials.We here report a facile and efficient approach for the synthesis of 2D woven supramolecular polymers by differentiated self-assembly through orthogonal noncovalent interactions.Importantly,the difference in binding strength of two orthogonal noncovalent interactions can be used to control the process of molecular weaving.Consequently,single-layered 2D woven supramolecular polymers were synthesized and fully characterized by various techniques.This study demonstrates a controllable method for molecular weaving,and will significantly hasten the development of molecularly woven materials.

Self-assembled Supramolecular Artificial Transmembrane Ion Channels:Recent Progress and Application

Natural protein channels have evolved with fantastic spatial structures,which play pivotal physiological functions in all living systems.Learning from nature,chemical scientists have developed a myriad of artificial transmembrane ion channels by using various chemical strategies,among which the non-covalent supramolecular ion channels exhibit remarkable advantages over other forms(e.g.,single-molecule ion channel),which exhibited facile preparation methods,easier structural modification and functionalization.In this review,we have systematically summarized the recent progress of supramolecular self-assembled artificial transmembrane ion channels,which were classified by different self-assembly mechanisms,such as hydrogen bonds,π-πinteractions,etc.Detailed preparation process and self-assembly strategies of the supramolecular ion channels have been described.Moreover,potential biomedical applications of the supramolecular ion channels have also been carefully discussed in this review.Finally,future opportunities and challenges facing this field were also elaborately discussed.It is anticipated that this review could provide a panoramic sketch and future directions towards the construction of novel artificial ion channels with novel functions and biomedical applications.

Phosphine-free synthesis of FeTe2 nanoparticles and self-assembly into tree-like nanoarchitectures

Manipulating the self-assembly of transition metal telluride nanocrystals(NCs) creates opportunities for exploring new properties and device applications. Iron ditelluride(FeTe2) has recently emerged as a new class of magnetic semiconductor with three-dimensional(3D) magnetic ordering and narrow band gap structure, yet the self-assembly of FeTe2 NCs has not been achieved. Herein, the tree-like FeTe2 nanoarchitectures with orthorhombic crystal structure have been successfully synthesized by hot-injection solvent thermal approach using phosphine-free Te precursor. The morphology, size, and crystal structure have been investigated using transmission electron microscopy(TEM), high-resolution TEM(HRTEM),and powder x-ray diffraction(XRD). We study the formation process of tree-like FeTe2 NCs according to trace the change of the sample morphology with the reaction time. It was found that the FeTe2 nanoparticles show oriented aggregation and self-assembly behavior with the increase of reaction time, which is attributed to size-dependent magnetism properties of the samples. The magnetic interaction is thought to be the driving force of nanoparticle self-organization.

Supramolecular Sheet Co(Ⅱ) Complex Assembled by Hydrogen Bond

The title complex, [ [ Co （Py） 2 （H20） 2 （ NO3 ）2 ] ] n （ 1 ） was synthesized by liquid/liquid diffusion method at room temperature. The complex crystallizes in monoclinic, space group P2 （1）/C, with a = 0.8775（6）nm, b=1.171 5（8）nm, c=0.7518（5）nm, V=0.739 3（9）nm3, C10H14CoN4O8, Mr= 377.18, Dc=1.694g/cm^3, μ=1.210mm^-1, F（000）=386, Z=2, the final R=0.0229 and wR= 0.066 1 for 3 137 observed reflections （I〉2σ（I））. In the structure of 1, the center atom of cobalt revealed a centrosymmetric, six-coordinate structure, with two Py ligands, two monodentate nitrate groups and two water molecules. It is notable that a series of hydrogen bonds （O-H…O） formed two kinds of rings exist in the structure, which linked neighboring six-coordinate polymer into a two-dimensional H-bonding network, and then assembled into a three-dimensional supramolecular architecture through electrostatic and hydrophobic interaction. In the structure, supramolecular sheet was observed, which contains alte .rnative organic and inorganic layers.

Self-assembled supramolecular networks at interfaces: Molecular immobilization and recognition using nanoporous templates

In this review a series of organic-based open porous networks are discussed, in which hydrogen bonds play an important role in network formation. Using these open networks as molecular templates: 1) a wealth of functional guest species can be immo- bilized; 2) fullerene molecules can be separated and recognized; 3) photoisomerization reactions can be observed by STM; 4) 1D molecular arrays can be constructed; and 5) heterogeneous bilayer structures can be formed. It is envisioned that these su- pramolecular networks might be developed into a new family of useful soft frameworks for studies toward shape-selective ca- talysis, molecular recognition and host-guest supramolecular chemistry.

Tunable aggregation-induced fluorescent and pressure-responsive luminescence supramolecular cages achieved by subcomponent self-assembly

Three discrete tetrahedral metallo-supramolecular cages were designed and constructed using truxenepended base ligands.Owing to the synergistic rigidifying effect of unsymmetric cyano-substituted oligo(pphenylene-vinylene)(u-COPV)suspended by the truxene skeleton,the resulting supramolecular cages were confirmed to exhibit significant aggregation-induced emission(AIE)accompanied by an interesting solvatochromic fluorescent behavior as well as a porous honeycomb-like state during aggregation.In particular,the anti-counterfeiting performance and emission behaviors of the cages in the solid state under external hydrostatic pressure were investigated.

Self-assembled nanostructures of a series of linear oligothiophene derivatives adsorbed on surfaces

Many previous studies have shown that the molecular structures of oligothiophene derivatives including molecular skeleton and alkyl chains have a significant effect on their self-assemblies on the surface.In this work, a series of linear oligothiophene derivatives(DCV-n T-Hex, n = 3~11) modified with terminal dicyanovinyls and alkyl chains were adopted to further investigate the different assembly behaviors at liquid-solid interface by scanning tunneling microscopy(STM). Interestingly, via the hydrogen bonding and van der Waals interactions, DCV-3T-Hex formed zigzag and flower structures while DCV-n T-Hex(n = 4~11) formed lamellar structures. Density functional theory(DFT) calculations show that for the most energetically favorable configurations of DCV-n T-Hex, the different distribution of alkyl chains affected intermolecular interactions, and ultimately led to the different assembled structures. The zigzag and flower structures of DCV-3T-Hex had preferential thermodynamic stability compared to other structures of DCV-n T-Hex(n = 4~11). In addition, self-assembled nanostructures of DCV-n T-Hex molecules with even numbers(n = 4, 6, 8, 10) were overall more stable than those with odd numbers(n = 5, 7, 9,11), and the stability of the self-assembled structure was weakened with the extension of the molecular backbone, individually. The orientation of molecular alkyl chains was found to greatly affect the intermolecular interactions and thus leading to various self-assembly structures of DCV-n T-Hex(n = 3~11).

Supramolecular Self-assembly Formed from Cucurbit[8]uril and p-Hydroxybenzoic Acid

The binding behavior of cucurbit[8]uril(Q[8])and p-hydroxybenzoic acid(p-HBA)has been investigated using ^(1)H NMR titration experiments,UV-Vis absorption,isothermal titration calorimetry(ITC),and X-ray crystallography.Results revealed that the Q[8]can accommodate two p-HBA molecules to form a 1:2 host-guest inclusion complex in solution,namely(p-HBA)2@Q[8].From a poorly scattering crystal,we were able to identify two symmetry unique Q[8]rings,but with different p-HBA fillings.The structure can be represented as Q[8]+1.5 p-HBA,which gives Q[8]@(p-HBA)2∙Q[8]@p-HBA as the structural formula.This supramolecular structure was screened for its ability to capture iodine.The experimental results showed that the adsorption efficiency of the supramolecular organic framework material for iodine capture was 43.8%,with an equilibrium adsorption capacity of 223.3 mg/g.

Pillar[6]arene-based supramolecular self-assemblies for twopronged GSH-consumption-augmented chemo/photothermal therapy

The abundant intracellular glutathione(GSH)in cancer cells severely undermines the therapeutic efficacy of different treatments due to their role in protecting cancer cells from the associated oxidative stress.Developing a highly integrated system to consume GSH would help to improve the therapeutic outcomes.In this study,supramolecular prodrug self-assemblies(SPSAs)with IR825 loaded inside were developed to consume GSH via two-pronged pathways while augmenting the therapeutic potency of chemo/photothermal treatment.SPSAs were prepared using water-soluble pillar[6]arene(WP[6])as host units and H_(2)O_(2)-responsive nitrogen mustard prodrug,chlorambucil-(phenylboronic acid pinacol ester)conjugates(Cb-BE),as the guests.When SPSAs were internalized by cancer cells,the generation of quinone methide(QM)from Cb-BE and singlet oxygen(^(1)O_(2))from irradiation-activated IR825 could consume GSH in a concerted way.As such,the therapeutic efficacies of the released chlorambucil and the accompanied hyperthermia were augmented toward synergistically inhibiting tumor growth.

Self-assembled supramolecular materials for photocatalytic H_(2)production and CO_(2)reduction

Photosynthetic organisms harness solar radiation to produce energy-rich compounds from water and atmospheric CO_(2)via exquisite supramolecular assemblies,which offers a design principle for highly efficient artificial photocatalytic systems.As an emerging research field,significant effort has been devoted to self-assembled supramolecular materials for photocatalytic H_(2)production and CO_(2)reduction.In this review,we introduce the basic concepts of supramolecular photocatalytic materials.After that,we will discuss recent advances in the preparation of supramolecular photocatalytic materials from zero-dimension to three-dimension which include molecular assemblies,micelles,hybrid nanoparticles,nanofibers,nanosheets,microcrystals,lipid bilayers,supramolecular organic frameworks,supramolecular metal-organic frameworks,gels,and host-guest metal-organic frameworks,etc.Furthermore,we show the recent progress in the photocatalytic properties of supramolecular photocatalytic materials,i.e.photocatalytic proton reduction,water splitting,CO_(2)to HCOOH,CO_(2)to CO,CO_(2)to CH4 conversions,etc.Finally,we provide our perspective for the future research,with a focus on the development of new structures and highly efficient photocatalysis.

Controlling Molecular Packing in Aqueous Metallosupramolecular Self-assembly by Ligand Geometry

The coordination geometry of d8 transition metal complexes has been successfully exploited as a tool to tune photophysical properties and self-assembly pathways of supramolecular polymerization processes,with a focus being primarily placed on organic media.Expanding such controlled supramolecular and photophysical properties to assemblies in aqueous media by molecular design is,however,still challenging due to the difficulty in programming noncovalent interactions in water.Herein,we tackle this challenge by analyzing the aqueous self-assembly of amphiphilic Pt(II)complexes of different molecular geometry in order to control self-assembly and metal−metal interactions in aqueous media.To this end,we have designed two Pt(II)complexes,1 and 2,containing an identical oligophenyleneethynylene(OPE)-based aromatic scaffold that differ in the molecular geometry(linear vs V-shaped)imposed by ligand substitution and studied their comparative self-assembly behavior in aqueous media.Even though both molecules follow the isodesmic mechanism of self-assembly,their structural difference strongly influences the molecular packing in aqueous media,which in turn impacts the photophysical properties(i.e.absence or presence of MMLCT)and the self-assembly outcome.While the molecular geometry for 2 enforces short Pt…Pt contacts driven by an efficient face-to-face stacking of the OPE backbone,the antiparallel packing of 1 with slight translational offset does not allow the formation of short Pt…Pt contacts.Such a distinct interplay of interactions for 1 and 2 in aqueous media leads to significant differences in photoluminescence.

Supramolecular flow chemistry: Construction of multiscale supramolecular assemblies by micro/nanofluidic techniques

The rapid and precise fabrication of multiscale supramolecular assemblies using micro/nanofluidic techniques has emerged as a dynamic area of research in supramolecular chemistry, materials chemistry, and organic chemistry. This review summarizes the application of micro/nanofluidic techniques in constructing supramolecular assemblies, including nanoscale supramolecular assemblies such as macrocycles and cages, microscale supramolecular assemblies such as metal organic frameworks (MOFs) and covalent organic frameworks (COFs), and macroscale supramolecular assemblies such as supramolecular hydrogels. Compared to conventional synthesis methods, micro/nanofluidic techniques for the production of supramolecular assemblies have significant advantages, including enhanced safety, high reaction rates, improved selectivity/yield, and scalability. Additionally, micro/nanofluidic systems facilitate the creation of precisely controllable micro/nanoconfined environments, allowing for a unique flow behavior that improves our understanding of the supramolecular self-assembly process. Such systems may also lead to the development of novel supramolecular assemblies that differ from those generated via traditional methods.

Regulation and application of supramolecular gel with circularly polarized luminescence

Supermolecular gel is a three-dimensional network structure assembled by small molecules or polymers in solvents through noncovalent interaction.The emergence of system complexity occurs spontaneously during the molecular self-assembly process.A multitude of chiral molecular self-assembly systems have been engineered,facilitating the achievement of circularly polarized luminescence(CPL)through the amalgamation of chiral entities with fluorophores.Hydrogen bonding,π-πstacking,and noncovalent forces,such as host-guest interactions and Van der Waals'forces,confer upon supramolecular gels the capacity to react to diverse stimuli.Due to the flexibility of supramolecular assembly,the CPL properties of supramolecular gels have rich controllability and can be used in various applications.In this review,we summarized the examples of CPL-active supramolecular gel assembly,and further summarized the assembly environment factors and external stimuli.Furthermore,the versatility of CPL applications in supramolecular gels is demonstrated,ranging from optical devices,information encryption,biosensing and chemical sensing,and other practical applications.In conclusion,the study provides insights into the multicultural factors influencing CPL in supramolecular gels,describes their applications in various domains,and presents future perspectives in the field.

Designed imidazole-based supramolecular catalysts for accelerating oxidation/hydrolysis cascade reactions

Reconstructing enzymatic active sites presents a significant challenge due to the intricacies involved in achieving enzyme-like scaffold folding and spatial arrangement of essential functional groups.There is also a growing interest in building biocatalytic networks,wherein multiple enzymatic active sites are localized within a single artificial system,allowing for cascaded transformations.In this work,we report the self-assembly of imidazole or its derivatives with fluorenylmethyloxycarbonyl-modified histidine and Cu2+to fabricate a supramolecular catalyst,which possesses catechol oxidase-like dicopper center with multiple imidazole as the coordination sphere.Transmission electron microscopy,low-temperature X-band continuous-wave electron paramagnetic resonance,K-edge X-ray absorption spectra/the extended X-ray absorption fine structure analysis,and density functional theory modeling were used for the structural characterization of the catalyst.The phenol derivatives and the dissolved oxygen were used as the substrates,with the addition of 4-aminoantipyrine to generate a red adduct with a maximum absorbance at 510 nm,for obtaining time-dependent absorbance change curves and estimating the activities.The results reveal that the addition of imidazole synergistically accelerates the oxidative activity about 10-fold and the hydrolysis activity about 14-fold than fluorenylmethyloxycarbonyl modified-histidine/Cu2+.The supramolecular nanoassembly also exhibits the ability to catalyze oxidation/hydrolysis cascade reactions,converting 2′,7′-dichlorofluorescin diacetate into 2′,7′-dichlorofluorescein.This process can be regulated through the methylation of the imidazole component at various positions.This work may contribute to the design of advanced biomimetic catalysts,and shed light on early structural models of the active sites of the primitive copper-dependent enzymes.