Synergistic fluorescent hydrogel actuators with selective spatial shape/color-changing behaviors via interfacial supramolecular assembly

Biomimetic intelligent polymeric hydrogel actuators with cooperative fluorescence-color switchable behaviors are expected to find great potential applications in soft robotics,visual detection/display,and camouflage applications.However,it remains challenging to realize the spatial manipulation of synergistic shape/color-changing behaviors.Herein,we report an interfacial supramolecular assembly(ISA)approach that enables the construction of robust fluorescent polymeric hydrogel actuators with spatially anisotropic structures.On the basis of this ISA approach,diverse 2D/3D soft fluorescent hydrogel actuators,including chameleon-and octopi-shaped ones with spatially anisotropic structures,were facilely assembled from two different fluorescent hydrogel building blocks sharing the same physically cross-linked agar network.Spatially control over synergistic shape/color-changing behaviors was then realized in one single anisotropic hydrogel actuator.The proposed ISA approach is universal and expected to open promising avenues for developing powerful bioinspired intelligent soft actuators/robotics with selective spatial shape/color-changing behaviors.

Regulating photothermal properties of near-infrared croconaine dyes by supramolecular assembly

The photochemical and photophysical properties of near-infrared(NIR)dyes are significantly influenced by their aggregation state and mesoscopic morphology.However,beyond chemical synthesis,the regulation mechanisms for the properties of NIR dyes,particularly with respect to photothermal properties of the aggregates,are not yet fully understood.Here,we investigate the photothermal behaviors of croconaine-based(CroA)NIR dyes containing dipeptide or amino acids moieties.The introduction of hydrogen bonding promotesπ-πstacking of croconaine center,which can efficiently regulate aggregation states and assembly structures in isopropanol.Under laser irradiation,CroA aggregates undergo aggregation-dissociation transition,the in-situ monomer generation process regulates two parameters of photothermal performance:heating rates and plateau photothermal temperatures.This study reveals the regulation effect of non-covalent bonding interactions on CroA aggregates,highlighting supramolecular assembly strategy not only facilitates to construct of photothermal nanomaterials with well-defined structures,but also provides an alternative and effective method for regulating photothermal performance of NIR dyes.

In situ thermoresponsive supramolecular assembly for switchable circularly polarized luminescence

The dynamic regulation of circularly polarized luminescence(CPL)holds profound significance in various fields,such as highlevel information storage and encryption.Here we developed a chiral amphiphilic molecule,CPSB-GLU-PEG350(CGP),composed of aggregation-induced emission(AIE)chromophores(Z)-4-(1-cyano-2-phenylvinyl)benzoic acid(CPSB),a chiral linker Glutamic acid and polyethylene glycol(PEG)thermoresponsive segments.Within the self-assembled supramolecular system formed by CGP,we have achieved in-situ temperature-responsive chiral structures,facilitating the thermal control switch of the CPL signal.Molecular dynamics simulations demonstrate the distinct behaviors of AIE and PEG units during the temperature-variable assembly process.Furthermore,by co-assembling achiral dye molecules with CGP,we have expanded the color range of the temperature-responsive CPL assembly system in situ and confirmed the occurrence of circularly polarizedF?rster resonance energy transfer(C-FRET)phenomenon in this process,which successfully enriched the strategies for in-situ CPL control in aqueous phases.In addition,the contactless radiative energy transfer of CPL can also be realized in this system,exhibiting more flexible temperature regulation of the CPL signal.This study provides a convenient and universal strategy for the construction of dynamically smart chiroptical materials.

Supramolecular assembly-derived carbon-nitrogen-based functional materials for photo/electrochemical applications: progress and challenges

Supramolecular chemistry during the synthesis of carbon-nitrogen-based materials has recently experienced a renaissance in the arena of photocatalysis and electrocatalysis.In this review,we start with the discussion of supramolecular assemblies-derived carbon-nitrogen-based materials’regulation from the aspect of morphology,chemical composition,and micro/nanostructural control.Afterwards the recent advances of these materials in energy and environment related applications,including degradation of pollutants,water splitting,oxygen reduction reactions,CO_(2) reduction reactions along with organic synthesis are summarized.The correlations between the structural features and physicochemical properties of the carbonnitrogen-based materials and the specific catalytic activity are discussed in depth.By highlighting the opportunities and challenges of supramolecular assembly strategies,we attempt an outlook on possible future developments for highly efficient carbon-based photo/electrocatalysts.

Multicolor Luminescent Carbon Nanoparticles： Synthesis, Supramolecular Assembly with Porphyrin, Intrinsic Peroxidase-Like Catalytic Activity and Applications

Luminescent carbon nanoparticles （CNPs） are newcomers to the world of nanomaterials and have shown great impact in health and environmental applications as well as being promising building blocks for future nanodevices because of their fascinating photoluminescence and potential to serve as nontoxic replacements for traditional heavy-metals-based quantum dots. Herein, fluorescent CNPs have been prepared from candle soot by re fluxing with HNO3 and subsequently separated by a single centrifugation. The CNPs can be represented by the empirical formula C1Ho.677Oo.586No.o15Nao.069, and have a size of 20-100 nm, height of 3.0 nm, lifetime of 7.31 ns ＋ 0.06 ns and quantum yield of -1.7%. Further studies demonstrate that： （1）the as-prepared CNPs exhibit excellent stability in biological media and their luminescence intensity does not change with ionic strength or pH in the physiological and pathological range of pH 4.5-8.8; （2） CNPs can act as electron donors and transporters and porphyrin can assemble onto CNPs through electrostatic and ^-stacking interactions to form porphyrin-CNPs supramolecular composites; （3）CNPs have strong intrinsic peroxidase-like activity. Based on this intrinsic peroxidase activity, a simple, cheap, and highly selective and sensitive colorimetric and quantitative assay has been developed for the detection of glucose levels. This assay has been used to analyze real samples, such as diluted blood and fruit juice.

Macroscopic Supramolecular Assembly and Its Applications

Macroscopic supramolecular assembly(MSA)has been a recent progress in supramolecular chemistry.MSA mainly focuses on studies of the building blocks with a size beyond ten micrometers and the non-covalent interactions between these interactive building blocks to form ordered structures.MSA is essential to realize the concept of"self-assembly at all scales"by bridging most supramolecular researches at molecular level and at macroscopic scale.This review summaries the development of MSA,the basic design principle and related strategies to achieve MSA and potential applications.Correspondingly,we try to elucidate the correlations and differences between"macroscopic assembly"and MSA based on intermolecular interactions;the design principle and the underlying assembly mechanism of MSA are proposed to understand the reported MSA behaviors;to demonstrate further applications of MSA,we introduce some methods to improve the ordered degree of the assembled structures from the point of precise assembly and thus envision some possible fields for the use of MSA.

Aggregation-induced emission systems involving supramolecular assembly

Aggregation-induced emission(AIE),as an exciting photophysical phenomenon,has been regarded as one frontier research topic within both ranges of molecular luminescence and materials science over the last two decades.Since controllable molecular ensembles with particular morphologies and tunable functions can be elegantly constructed in the realm of supramolecular chemistry,the integration of supramolecular assembly and AIE systems can expectedly bring about luminescent materials with tunable emission and tailorable well-ordered architectures.In this review,we will provide a summary of the creation and working mechanisms of AIE systems involving supramolecular systems that are driven by different supramolecular driving forces including hydrogen bonding,host−guest interactions,metal coordination,and π-π interactions.The morphological and photoluminescent features of these AIE-active supramolecular assemblies will be elucidated,and the regulated fluorescence properties of the AIEgens induced by the assembling-disassembling processes will be discussed in detail.

Gas-Induced Phase Transition of Dipeptide Supramolecular Assembly

The manipulation of supramolecular assembly enables single-component architectures to possess diverse structures and functions.Here,we report directed phase transitions of dipeptide supramolecular gel to crystals with excellent selectivity and tunable mechanical properties.To be specific,lamellar-to-orthorhombic rearrangement of dipeptide molecules in the supramolecular assembly was guided by application of ammonia gas,while lamellar-tohexagonal realignment was generated upon water vapor exposure of the assembly.Importantly,this crystal phase control originated from distinct gas-mediated reconstitution of hydrogen-bonding interactions,which endowed the dipeptide materials with remarkably modulated stiffness.The selective phase transformation offers a simple and effective platform for self-assembling peptide crystals with diverse long-range-ordered structures from a single gel-state aggregation.This work opens up new perspectives on peptide-based biomaterials via gas-directed hydrogen-bonding chemistry.

Synergistic activation of photoswitchable supramolecular assembly based on sulfonated crown ether and dithienylethene derivative

Conformational regulation among two or more distant sites is not only one of the main pathways to accomplish multiple tasks in complex biological systems but also represents a powerful strategy to obtain stimuli-responsive supramolecular nanoconstructs with tailored physicochemical performance.We herein report the fabrication of a photochromic supramolecular assembly,which can be synergistically activated by the conformational regulation with bis(4,8-disulfonato-1,5-naphtho)-32-crown-8 and then reversibly switched by the through-space communication between restricted stilbazolium salt and photochromic dithienylethene.This work demonstrates that the synergistic conformational modulation via intra-and intermolecular interactions can be developed as a generalizable approach to construct more advanced biomimetic nanomaterials.

Supramolecular Assembly Models of siRNA Delivery Systems

Small interfering RNA(siRNA)technology,which could be able to silence specific targeted mRNAs rapidly and efficiently,has been regarded as a novel and potent gene therapeutic approach for diseases,such as cancers,in-fections,inflammations and neurological disorders.However,some conspicuous intrinsic defects of siRNA including the poor cellular uptake,low biological stability,unfavorable pharmacokinetics and bio-distribution properties,have hindered further applications in clinic.Therefore,it is prerequisite to design safe and effective siRNA delivery systems for the successful development of siRNA-based various diseases therapeutics.This review aims to analyze and summarize these supramolecular assembly models in the process of siRNA delivery,namely recent nanotech-nological strategies for carrying siRNA by using diverse non-viral vehicles such as cationic liposomes,stable nucleic acid lipid particles(SNALPs),cationic polymers,cationic dendrimers,inorganic nanoparticles and others.Eventually,it is concluded with future perspectives of siRNA therapeutics in the field of non-viral carriers.

Ordered supramolecular assembly of bis[3,4,12,13,21,22,30,31-octa(dodecylthio)-2,3-naphthalocyaninato]erbium at the air/water interface

The supramolecular assembly of bis[3, 4, 12, 13, 21, 22, 30, 31-octa(dodecylthio)-2, 3-naphthalocyaninato] erbium complex (Er[Nc(SC12H25)8]2) was fabricated at the air/water interface by Langmuir monolayer technique. Surface pressure-area isotherm indicates that stable monolayer is formed. The monolayer morphology on mica was investigated by atomic force microscopy (AFM). Columnar domains of ca. 100 nm X (20–30) nm appearing in the micrograph have ordered orientation. Polarized UV-vis spectra and small-angle X-ray diffraction pattern show that the macrocycles tilt in the monolayer. The orientation angle of the naphthalocyanine ring with respect to the substrate was found to be ca. 54°. Each monolayer is ca. 3.53 nm thick. The columnar domain comprises 4–6 rows of columnar supramolecular assemblies where the molecules stack face-to-face.

Hydrothermal Synthesis and Crystal Structure of a New Supramolecular Channel Framework Based on Cu Complexes and Polyoxovanadate:[Cu(I)(phen)_2]_5[HV_(15)O_(36)(Cl)]_(0.65)[H_3V_(16)O_(38)(Cl)]_(0.35)·2H_2O

A new compound [Cu（I）（phen）2]5[HV15O36（Cl）]0.65[H3V16O38（Cl）]0.35·2H2O 1 （phen = 1,10′-phenanthroline） has been prepared from the hydrothermal reaction of V2O5, CuCl, phen, H2C2O4·2H2O, THMAM （tris（hydroxymethyl）aminomethane） and H2O in the molar ratio of 3：1：1：0.5：2.5：1400. Compound 1 crystallizes in the space group P42212 of the tetragonal system with a = b = 21.5009（8）, c = 28.401（2） A, V= 13129.5（12） A^3 Z = 4, Dc = 1.800 g/cm^3, μ（MoKa） = 1.932 mm^-1, λ（MoKa） = 0.71073 A, F（000） = 7063.4, C120H81.20ClCu5N20O38.7V15.35, Mr = 3557.58, the final R = 0.0594 and wR= 0.1320 for 7761 observed reflections （I 〉 2σ（I））. Structure analysis shows that 1 exhibits a 3D channel framework formed by the supramolecular assembly of Cu complexes and polyoxovanadate clusters via intermolecular hydrogen bonding, and the channels contain Cu complexes. Other characterizations by elemental analysis, XPS, IR, XRD and thermal analysis are also described.

Formation of Amino Acid Bridged Zinc Bisporphyrinethylenediamine Linear Supramolecular Array: UV-visible and ~1HNMR evidence

Coordination behavior of bidentate ligand ethylenediamine with a new chiral zine bisporphyrin O.O-C,-AA-C,-(TPP),Zn, was investigated by Uv-Vis titration and 'H-NMRspectroscopy. which further evidenced that ac-c,-AA-c,-(TPP)Zn, tends to form linear assemblywith ethylenediamine in chloroform.

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.

Recent advances in post-chiroptical manipulation of supramolecular aggregates assembled with molecular modules

Recently,various supramolecular assembly systems have been identified where the pre-existing chiral supramolecular structure can be manipulated through environmental adjustments,such as temperature,solvent,and concentration.These changes result in diverse microscopic morphologies during the assembly process and induce chiroptical variations,particularly in circular dichroism(CD)and circularly polarized luminescence(CPL)spectra.These chiroptical properties serve as direct indicators of the chiral supramolecular structure and hold promise for applications in sensing,molecular recognition,asymmetric synthesis,and material science.This review focuses on research published in the last five years,highlighting instances where assembled structures aggregated by small organic molecular modules demonstrate in-situ chiroptical changes through external condition control.It categorizes and discusses different modes of regulation,aiming to offer insights and guidelines for exploring dynamic changes in assembly processes and designing in-situ adjustable structures of assembly modules.

Metalloprotein-inspired supramolecular photodynamic nanodrugs by multicomponent coordination for deep penetration and enhanced biofilm eradication

Bacterial infections exacerbate the formation of bacterial biofilms,leading to resistance to traditional drugs,persistent infection,and even threatening patient’s life.Efficient antimicrobial materials against drug-resistant bacterial biofilms are highly desired.In this study,a photodynamic nanodrug with bacterial targeting was constructed by cooperative coordination of zinc ion with an antimicrobial peptide with hydrophobic tripeptides on the side chains and the photosensitizer chlorin e6.The supramolecular nanodrug with a uniform spherical structure possessed high photosensitizer loading capacity and enhanced photodynamic efficacy,which could deep penetrate and eradicate methicillin-resistant Staphylococcus aureus(MRSA)biofilms upon 655 nm laser irradiation.Furthermore,in vivo experiments verified the efficient elimination of MRSA biofilms on implanted catheters.This study provides a novel strategy to fabricate metalloprotein-inspired supramolecular photodynamic nanodrugs against drugresistant bacterial biofilms-associated infections in vivo.

Constructing 2D ultrathin graphene oxide membranes with supramolecular-assembled nano-adhesives for enhancing water stability

Atomic-thick two-dimensional(2D)graphene oxide(GO)has emerged as an ideal building block in developing ultrathin 2D membranes for separating substances.However,due to the negative charge of GO sheets when hydrated,electrostatic repulsion causes GO membranes to disintegrate easily in water,limiting their wide application in aqueous solutions.Here,we introduce and apply the concept of localized gluing by designing ultra-small supramolecular-assembled nanoparticles as nanoadhesives(NPA)to construct robust GO membranes with a thickness of only 24 nm.The supramolecular-assembled NPA were synthesized by cyclodextrin(CD)and tannic acid(TA)with a uniform size distribution of about 4.5 nm,and exposed surface pyrogallols that could strongly interact with GO sheets.The physical sizing of the NPA confines the interlayer spacing and maintains the nanochannel,while the natural molecular properties of the NPA enhance the connection between adjacent layers and inhibit swelling detachment.The fabricated ultrathin 2D membranes show a remarkable two times enhancement of water permeance over pristine GO membranes and exhibit excellent durability with record-breaking stability for 720 h immersion in water.This strategy provides meaningful insights into the design and fabrication of robust ultrathin membranes for practical application.

Carrier-free supramolecular nanomedicines assembled by small-molecule therapeutics for cancer treatment

Nanomedicines have shown great promise in cancer therapy,but are challenged by limited drug loading,safety concerns of drug carriers,and complexity of function integration.Recently,carrier-free nanomedicines produced by supramolecular assembly of small-molecule therapeutic functionalities and their conjugates were proposed to address these issues.These nanomedicines achieve very high drug loading,enhanced tumor accumulation and improved therapeutic efficiency,and avoid carrier-related safety problems.In this review article,the applications of these nanomedicines in chemotherapy,photodynamic therapy,photothermal therapy as well as combination therapies will be reviewed.The concept of nanomedicine design and mechanism of supramolecular assembly will be discussed.Finally,future perspectives of carrier-free supramolecular nanomedicines for cancer therapy will be highlighted.

Pseudorotaxane Ligand-Induced Formation of Copper(I)lodide Cluster Based Assembly Materials:From Zero to Three Dimensional

Comprehensive Summary In this work,we have successfully obtained a series of novel copper(I)–iodide clusters(CuI NCs)based assembly materials by combining supramolecular pseudorotaxane ligands{[Mebpe^(+)]PF_(6)^(–)@CB[6](CB[6]=cucurbit[6]uril),L’·PF_(6)}and linkers{BPHF@CB[6],[BPHF=C_(14)H_(20)N_(4)(PF_(6))_(2)],L·PF_(6)},including discrete cluster CuI 1 and extended cluster organic frameworks MORF 1 and MORF 2.CuI 1 can be described as a dumbbell-shaped molecule with its body-centered site and two vertexes respectively occupied by one[Cu_(5)I_(6)]^(–)cluster and two CB[6]held together by two L’·PF_(6) ligands.The crystal structures of MORF 1 and MORF 2 are 1D anionic chain and four-fold interpenetrated 3D cationic diamondoid structure,respectively,which all featured intriguing alternating CB[6]and CuI NCs.

Supramolecular assemblies of cucurbit[n]urils and 4-aminopyridine controlled by cucurbit[n]uril size(n=5,6,7 and 8)

The binding interactions between 4-aminopyridine(4-AP) and a series of cucurbit[n]urils(Q[5], Q[6],TMe Q[6], Q[7], Q[8]) have been studied using1H NMR spectroscopy, UV–vis absorption spectroscopy,isothermal titration calorimetry(ITC) and X-ray crystallography. The data indicates that the Q[5]@4-AP complex exhibits exo binding, which is not observed in the other four host-guest complexes. Furthermore,X-ray crystallography clearly reveals how the Q[n]s bind with 4-AP to form complexes, for example Q[5]forms an outer-surface complex, whilst Q[6], TMe Q[6] and Q[7] formed 1:1 host and guest type complexes, and Q[8] formed a stable 1:2 ternary complex due to its large cavity, which can accommodate two 4-AP molecules.