Phenanthrothiophene-Triazine Star-Shaped Discotic Liquid Crystals: Synthesis, Self-Assembly, and Stimuli-Responsive Fluorescence Properties

Lipophilic biphenylthiophene- and phenanthrothiophene-triazine compounds, BPTTn and CPTTn, respectively, were prepared by a tandem procedure involving successive Suzuki-Miyaura coupling and Scholl cyclodehydrogenation reactions. These compounds display photoluminescence in solution and in thin film state, solvatochromism with increasing solvent's polarity, as well as acidochromism and metal ion recognition stimuli-responsive fluorescence. Protonation of BPTT10 and CPTT10 by trifluoroacetic acid results in fluorescence quenching, which is reversibly restored once treated with triethylamine (ON-OFF switch). DFT computational studies show that intramolecular charge transfer (ICT) phenomena occurs for both molecules, and reveal that protonation enhances the electron-withdrawing ability of the triazine core and reduces the band gap. This acidochromic behavior was applied to a prototype fluorescent anti-counterfeiting device. They also specifically recognize Fe3+ through coordination, and the recognition mechanism is closely related to the photoinduced electron transfer between Fe3+ and BPTT10/CPTT10. CPTTn self-assemble into columnar rectangular (Colrec) mesophase, which can be modulated by oleic acid via the formation of a hydrogen-bonded supramolecular liquid crystal hexagonal Colhex mesophase. Finally, CPTTn also form organic gels in alkanes at low critical gel concentration (3.0 mg/mL). Therefore, these star-shaped triazine molecules possess many interesting features and thus hold great promises for information processing, liquid crystal semiconductors and organogelators.

Fluoride-Ion-Responsive Sol-Gel Transition in an L-Cysteine/AgNO3 System: Self-Assembly Peculiarities and Anticancer Activity

Supramolecular hydrogels based on low-molecular-weight compounds are a unique class of so-called "soft" materials, formed by weak non-covalent interactions between precursors at their millimolar concentrations. Due to the variety of structures that can be formed using different low-molecular-weight gelators, they are widely used in various fields of technology and medicine. In this study, we report for the first time an unusual self-assembly process of mixing a hydrosol obtained from L-cysteine and silver nitrate (cysteine-silver sol-CSS) with sodium halides. Modern instrumental techniques such as viscosimetry, UV spectroscopy, dynamic light scattering, zeta potential measurements, SEM and EDS identified that adding fluoride anions to CSS is able to form stable hydrogels of a thixotropic nature, while Cl-, Br- and I- lead to precipitation. The self-assembly process proceeds using a narrow concentration range of F-. An increase in the fluoride anion content in the system leads to a change in the gel network morphology from elongated structures to spherical ones. This fact is reflected in a decrease in the gel viscosity and a number of gel-sol-gel transition cycles. The mechanism of F-'s interaction with hydrosol includes the condensation of anions on the positive surface of the CSS nanoparticles, their binding via electrostatic forces and the formation of a resulting gel carcass. In vitro analysis showed that the hydrogels suppressed human squamous carcinoma cells at a micromolar sample concentration. The obtained soft gels could have potential applications against cutaneous malignancy and as carriers for fluoride anion and other bioactive substance delivery.

Achiral Solvent Inversed Helical Pathway and Cosolvent Controlled Excited-State "Majority Rule" in Enantiomeric Dansulfonamide Assemblies

Achiral solvents are commonly utilized to induce the self-assembly of chiral molecules. This study demonstrates that achiral solvents can trigger helicity inversion in the assemblies of dansyl amphiphiles and control the excited-state "majority rule" in assemblies composed of pure enantiomers, through variation of the cosolvent ratio. Specifically, enantiomers of dansyl amphiphiles self-assemble into helical structures with opposite handedness in methanol (MeOH) and acetonitrile (MeCN), together with inversed circular dichroism and circularly polarized luminescence (CPL) signals. When a mixture of MeOH and MeCN is employed, the achiral cosolvents collectively affect the CPL of the assemblies in a way similar to that of "mixed enantiomers". The dominant cosolvent governs the CPL signal. As the cosolvent composition shifts from pure MeCN to MeOH, the CPL signals undergo a significant inversion and amplification, with two maxima observed at ≈20% MeOH and 20% MeCN. This study deepens the comprehension of how achiral solvents modulate helical nanostructures and their excited-state chiroptical properties.

Solvent selective gelation of cetyltrimethylammonium bromide: structure, phase evolution and thermal characteristics

We report herein the gelation behaviour of cetyltrimethylammonium bromide (CTAB), a cationic surfactant, in a variety of solvent compositions. A turbid gel of CTAB in a binary solvent mixture at a critical composition was observed to be 1 : 3 v/v toluene : water. The molecular structure of the as-formed gel was investigated by X-ray diffraction and microscopic techniques, namely, optical and polarizing microscopy, scanning electron microscopy and small-angle X-ray scattering (SAXS). The phase evolution has been studied using UV-visible transmittance measurements and the thermal characteristics of the gel by differential scanning calorimetry measurements. SAXS studies, in conjunction with molecular modelling, revealed the gel to assemble as lamellae with high interdigitation of bilayer assembly of CTAB molecules with predominant non-covalent interactions, where the gel lamellae were inferred from the interplanar spacings. Rheological studies revealed the viscoelastic nature of the CTAB gels. The ability to form a gel has been evaluated in several polar solvents, such as methanol and chloroform, and non-polar solvents, such as toluene and carbon tetrachloride.

Understanding multicomponent low molecular weight gels from gelators to networks

BACKGROUND

The construction of gels from low molecular weight gelators (LMWG) has been extensively studied in the fields of bio-nanotechnology and other fields. However, the understanding gaps still prevent the prediction of LMWG from the full design of those gel systems. Gels with multicomponent become even more complicated because of the multiple interference effects coexist in the composite gel systems.

AIM OF REVIEW

This review emphasizes systems view on the understanding of multicomponent low molecular weight gels (MLMWGs), and summarizes recent progress on the construction of desired networks of MLMWGs, including self-sorting and co-assembly, as well as the challenges and approaches to understanding MLMWGs, with the hope that the opportunities from natural products and peptides can speed up the understanding process and close the gaps between the design and prediction of structures.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review is focused on three key concepts. Firstly, understanding the complicated multicomponent gels systems requires a systems perspective on MLMWGs. Secondly, several protocols can be applied to control self-sorting and co-assembly behaviors in those multicomponent gels system, including the certain complementary structures, chirality inducing and dynamic control. Thirdly, the discussion is anchored in challenges and strategies of understanding MLMWGs, and some examples are provided for the understanding of multicomponent gels constructed from small natural products and subtle designed short peptides.

Scrolling in Supramolecular Gels: A Designer's Guide

Gelation by small molecules is a topic of enormous importance in catalysis, nanomaterials, drug delivery, and pharmaceutical crystallization. The mechanism by which gelators self-organize into a fibrous gel network is poorly understood. Herein, we describe the crystal structures and gelation properties of a library of bis(urea) compounds and show, via molecular dynamics simulations, how gelator aggregation progresses from a continuous pattern of supramolecular motifs to a homogeneous fiber network. Our model suggests that lamellae with asymmetric surfaces scroll into uniform unbranched fibrils, while sheets with symmetric surfaces undergo stacking to form crystals. The self-assembly of asymmetric lamellae is associated with specific molecular features, such as the presence of narrow and flexible end groups with high packing densities, and likely represents a general mechanism for the formation of small-molecule gels.

Differentiating aliphatic and aromatic alcohols using triazine-based supramolecular organogelators: end group-specific selective gelation with chain length of alcohols

Supramolecular gels have an extensive range of potential applications, out of which stimuli-responsive materials are a topic of contemporary research. Gels being kinetically entrapped materials can be tuned to different forms using external chemical stimuli. In this context, three different triazine gelators, each containing a unique end group, were examined for gelation in various solvent systems. Nevertheless, the gelation was limited to only alcoholic solvents, suggesting that the hydrogen bonds between the gelating solvent and gelator play a crucial role in gelation. Further, it was found that these gelators could gelate only with aliphatic alcohols, which could be degelled easily using aromatic alcohols. The three gelators exhibited distinct gelation of aliphatic alcohols based on their end groups. The gelator with the polar-aromatic end group (C5H4N) was found to gelate with lighter alcohols, whereas that with the nonpolar aromatic end group (C6H5) was found to prefer higher alcohols. The MGC and Tgel values were also found to depend on the alkyl chain length/branching of the alcohols. The crystal structure of one of the gelators provides insights into the model structure of the gels. Cyclohexanol was the only solvent that could produce gels with all three of the as-synthesised gelators. The process of degelation by aromatic alcohols was monitored at different points of the disassembly process by rheological and morphological measurements to understand the extent of controlled degelation. These gels have great potential for use in controlled drug delivery and chemical sensing, among other areas.

Amphiphilic Low-Molecular-Weight Gelators Bearing β-S-N-Acetylglucosamine Linked to a Tartaric Acid Scaffold: Synthesis, Self-Assembly and Wheat Germ Agglutinin Binding

The self-assembly of carbohydrate-based amphiphiles can lead to colloidal soft materials such as supramolecular gels featuring highly desirable characteristics like biodegradability and biocompatibility. The report herein presents the synthesis, characterization and supramolecular self-assembly, physical gelation and wheat lectin binding of two structurally related amphiphilic compounds having β-S-N-acetylglucosamine residues linked to a 2,3-diacyl-N,N'-dipropargylated-l-tartaric diamide. A 1-thio-β-N-acetyl-d-glucosamine precursor attached to a conveniently functionalized linker with an azido group was synthesized by means of a one-pot procedure followed by deprotection. A click reaction successfully led to the two amphiphiles, which differed in length of the fatty acid attached to the tartaric acid scaffold. Although both compounds are poorly soluble in water and organic solvents, the difference in terms of hydrophilic moieties provided them with distinct supramolecular gelation properties. While the presence of an octadecyl chain produced a hydrogelator, the dodecadecyl homologue would only form weak gels in DMSO. SEM and rheology experiments confirmed the characteristic fibrillar morphology and viscoelastic properties, in agreement with the presence of physical gels. Both amphiphiles were able to interact reversibly with wheat germ agglutinin (WGA), a lectin that specifically recognizes GlcNAc residues, indicating a potential use in the food industry, as a gluten sensitivity manager, as well as in health-related industries, for example, for drug delivery systems.

Supramolecular gels - a panorama of low-molecular-weight gelators from ancient origins to next-generation technologies

Supramolecular gels, self-assembled from low-molecular-weight gelators (LMWGs), have a long history and a bright future. This review provides an overview of these materials, from their use in lubrication and personal care in the ancient world, through to next-generation technologies. In academic terms, colloid scientists in the 19th and early 20th centuries first understood such gels as being physically assembled as a result of weak interactions, combining a solid-like network having a degree of crystalline order with a highly mobile liquid-like phase. During the 20th century, industrial scientists began using these materials in new applications in the polymer, oil and food industries. The advent of supramolecular chemistry in the late 20th century, with its focus on non-covalent interactions and controlled self-assembly, saw the horizons for these materials shifted significantly beyond their historic rheological applications, expanding their potential. The ability to tune the LMWG chemical structure, manipulate hierarchical assembly, develop multi-component systems, and introduce new types of responsive and interactive behaviour, has been transformative. Furthermore, the dynamics of these materials are increasingly understood, creating metastable gels and transiently-fueled systems. New approaches to shaping and patterning gels are providing a unique opportunity for more sophisticated uses. These supramolecular advances are increasingly underpinning and informing next-generation applications - from drug delivery and regenerative medicine to environmental remediation and sustainable energy. In summary, this article presents a panorama over the field of supramolecular gels, emphasising how both academic and industrial scientists are building on the past, and engaging new fundamental insights and innovative concepts to open up exciting horizons for their future use.

Stimuli responsive gelation of tert-butylacetic acid based LMOGs - applications in remediation of marine oil spills, dye removal and heavy metal sensing

Tert-butylacetic acid based amides containing a structural backbone, a hydrogen bonding linker and a bulky end group have been synthesized (TBA1-TBA6) and explored for gelation of fuel oils and organic solvents. The importance of the tert-butyl group in driving the assembly towards gelation has been highlighted in our previously reported pivalamide-based phase selective organogelators (PSOGs). Both groups of compounds have been scrutinized and the effect of an additional methylene group in the newly synthesized series of compounds (on the gelation behavior, single crystal structure, non-covalent interactions responsible for gelation, morphology, dye absorption, etc.) were probed. Compounds TBA1-TBA6 were also utilized for sensing heavy metal ions and transition metal ions present in aqueous medium. They display phase-selective gelation of oil in the presence of biphasic systems (oil-sea water) when added in powder form as well as in solution form, and hence, make excellent candidates for containing oil spills in water bodies. Overall, both these libraries form a class of smallest molecules ever employed for successful organogelation behavior.

Facile one-pot multicomponent synthesis of peptoid based gelators as novel scaffolds for drug incorporation and pH-sensitive release

Infections caused by bacteria are the primary cause of illness and death globally, and antibiotics are the most commonly used medications to treat them. However, there are certain inherent problems in administering these drugs without any changes to their effectiveness. In order to sustain the targeted dosage over time, the use of a biocompatible local drug delivery system using low molecular mass gelators is preferred as a potential approach to reduce its side effects. Low molecular weight organic gelators (LMWOGs) have drawn a lot of attention due to their numerous and varied applications in multiple fields. But nowadays its quite a challenging task to synthesize new types of LMWOGs that can fill the significant gap towards potential applications. In this work, we have explored a multicomponent pathway for the synthesis of a small repertoire of peptoids from simple building blocks by a one-pot Ugi reaction. A variety of novel effective low molecular weight organic gelators have been synthesized, leading to the formation of stable self-assembled aggregates in various solvents such as DMSO, aqueous DMSO, and methanol. Consequently, these aggregates give rise to the creation of organogels and organo/hydrogels. The gels have a minimum gelation concentration (MGC) of 1-2% w/v with high thermal stability. Furthermore, successful encapsulation and release of metronidazole (MZ) were achieved within the gel matrix under physiological pH conditions at 37 °C, ensuring the preservation of its structural and functional properties. The results demonstrated that the release rate of MZ from the organo/hydrogels is contingent on pH, exhibiting a gradual and regulated release in mild alkaline environments. Moreover, the devised system displayed noteworthy antimicrobial efficacy against E. coli, underscoring the potential of these novel low molecular weight organic gels (LMWOGs) as effective drug delivery systems in the pharmaceutical industry. The gel formulations exhibit biocompatibility and negligible cytotoxicity, as evidenced by cell viability studies conducted using the MTT assay.

Development of furan-2,5-dicarboxylic acid (FDCA)-based organogelators

Organogels are used in a wide range of applications for which the development of new bio-based organogelators is highly desirable. While furan-2,5-dicarboxylic acid (FDCA) is a promising molecule for the synthesis of bio-based polyesters, it has never been used in the context of organogels. This study explores the possibility to design FDCA-based organogelators that self-assemble into fibrillar networks stabilized by hydrogen bonding. Gelation tests show the versatility of this gelator family with a wide variety of gelled liquids, especially apolar liquids. The structure of the gels was investigated by FTIR and CD spectroscopies, crystallography, powder X-ray diffraction and rheology.

Development of Gelled-Oil Nanoparticles for the Encapsulation and Release of Berberine

In this study, a new drug carrier based on gelled-oil nanoparticles (GNPs) was designed and synthesized for the encapsulation and release of the model hydrophobic drug, berberine chloride (BCl). Two compositions with different oil phases were examined, sesame oil (SO) and cinnamaldehyde (Cin), which were emulsified with water, stabilized with Tween 80 (Tw80), and gelled using an N-alkylated primary oxalamide low-molecular-weight gelator (LMWG) to give stable dispersions of GNPs between 100 and 200 nm in size. The GNP formulation with Cin was significantly favored over SO due to (1) lower gel melting temperatures, (2) higher gel mechanical strength, and (3) significantly higher solubility, encapsulation efficiency, and loading of BCl. Also, the solubility and loading of BCl in Cin were significantly increased (at least 7-fold) with the addition of cinnamic acid. In vitro release studies showed that the release of BCl from the GNPs was independent of gelator concentration and lower than that for BCl solution and the corresponding nanoemulsion (no LWMG). Also, cell internalization studies suggested that the N-alkylated primary oxalamide LMWG did not interfere with the internalization efficiency of BCl into mouse mast cells. Altogether, this work demonstrates the potential use of these new GNP formulations for biomedical studies involving the encapsulation of drugs and nutraceuticals and their controlled release.

Liquid Crystal Assembly for Ultra-dissymmetric Circularly Polarized Luminescence and Beyond

Circularly polarized luminescence (CPL) is attracting much interest because it can carry extensive optical information. CPL shows left- or right-handedness and can be regarded as part of high-level visual perception to supply an extra dimension of information with regard to regular light. A key to meeting the needs for practical applications is to develop the emerging field of ultra-dissymmetric CPL. Chiral liquid crystal (LC) assemblies─otherwise referred to as cholesteric liquid crystals (CLCs)─are essentially organized helical superstructures with a highly ordered one-dimensional orientation, and distinctly superior to regular helical supramolecules. CLCs can achieve a perfect equilibrium of molecular short-range interaction and long-range orientational order, enabling molecule-scale chirality on a helical pitch and observable scale. LC assembly could be an ideal strategy for amplifying chirality, making it accessible to ultra-dissymmetric CPL. Herein, we focused on some basic but important issues regarding CPL: (i) How can CPL be created from chiral dyes? (ii) Is the chirality of luminescent dyes an essential factor for the generation of CPL? That is, can all chiral dyes emit CPL and vice versa? (iii) How can CPL be transferred within intermolecular systems, and what principles of CPL transmission should be followed? Given these queries and our work, in this Perspective we discuss the generation, transmission, and modulation of CPL with chiral LC assembly, aiming to design and build up novel chiroptical materials. Recent applications of CPL-active LC microstructures in three-dimensional displays, circularly polarized lasers, and asymmetric catalysis are also discussed.

Recent advances in the development of europium(III) and terbium(III)-based luminescent supramolecular metallogels

In the recent past, special attention has been paid to the development of metallogels as novel luminescent materials from rationally designed gelators with lanthanide ions, especially europium (Eu(III)) and terbium (Tb(III)) metal ions. Lanthanide (Ln(III)) based metallogels possess various useful properties with an extensive range of applications in the field of advanced materials, and electronic and bio-technologies. Lanthanide ions in coordination with appropriate sensitizer ligands can reproduce metal-based optical, redox, and electronic properties in soft gel materials. The optical properties of the luminescent Ln(III) based metallogels can be tuned over the complete visible spectrum (400-750 nm) including the generation of white light by mixing both Eu(III) and Tb(III) with the ligand in various stoichiometric ratios. Additionally, the dynamic nature of the lanthanide-ligand (Ln-N) coordination bond allows the Ln(III) based metallogels to respond to various external stimuli. Luminescent self-healing supramolecular gels using organic ligands as 'hosts' and Ln(III) ions as 'guests' are also a current topic of research interest. In this review, we discuss and summarize some selected recent examples of newly developed luminescent Eu(III) and Tb(III) based supramolecular metallogels with potential applications in the fields of optoelectronic devices, stimuli responsiveness, self-healing, luminescent films, and sensors.

Process Dependent Complexity in Multicomponent Gels

Mixing low molecular weight gelators (LMWGs) can be used to combine favorable properties of the individual components within a multifunctional gel. Such multicomponent systems are complex enough in themselves but the method of combining components is not commonly considered something to influence self-assembly. Herein, two multicomponent systems comprising of a naphthalene-based dipeptide hydrogelator and one of two modified naphthalene diimides (NDIs), one of which forms gels, and the other does not, are investigated. These systems are probed, examining the structures formed and their gel properties (when preparing a solution from either a mixed powder of both components or by mixing pre-formed solutions of each component) using rheology, small angle neutron scattering (SANS), and absorbance spectroscopy. It is found that by altering the method of preparation, it is can either induce self-sorting or co-assembly within the fibers formed that underpin the gel network.

The Effect of Branched Alkyl Chain Length on the Properties of Supramolecular Organogels from Mono-N-Alkylated Primary Oxalamides

Mono-N-alkylated primary oxalamide derivatives with different sized branched alkyl tail-groups were excellent low molecular weight gelators for a variety of different organic solvents with different polarities and hydrogen-bonding abilities. Solvent-gelator interactions were analyzed using Hansen solubility parameters, while ¹H NMR and FTIR spectroscopy were used to probe the driving forces for the supramolecular gelation. The molecular structures of the twin tail-groups did not significantly affect the supramolecular gelation behavior in different solvents. However, for select solvents, the molecular structures of the tail-groups did have a significant effect on gel properties such as the critical gelator concentration, thermal stability, gel stiffness, gel strength, network morphology, and molecular packing. Finally, metabolic activity studies showed that the primary alkyl oxalamide gelators had no effect on the metabolic activity of mouse immune cells, which suggests that the compounds are not cytotoxic and are suitable for use in biomedical applications.

Direct observation of long-range chirality transfer in a self-assembled supramolecular monolayer at interface in situ

Due to the interest in the origin of life and the need to synthesize new functional materials, the study of the origin of chirality has been given significant attention. The mechanism of chirality transfer at molecular and supramolecular levels remains underexplored. Herein, we study the mechanism of chirality transfer of N, N'-bis (octadecyl)-_L-_/D-(anthracene-9-carboxamide)-glutamic diamide (_L-_/D-GAn) supramolecular chiral self-assembled at the air/water interface by chiral sum-frequency generation vibrational spectroscopy (chiral SFG) and molecular dynamics (MD) simulations. We observe long-range chirality transfer in the systems. The chirality of C_α-H is transferred first to amide groups and then transferred to the anthracene unit, through intermolecular hydrogen bonds and π-π stacking to produce an antiparallel β-sheet-like structure, and finally it is transferred to the end of hydrophobic alkyl chains at the interface. These results are relevant for understanding the chirality origin in supramolecular systems and the rational design of supramolecular chiral materials.

Sugar-Based Phase-Selective Supramolecular Self-Assembly System for Dye Removal and Selective Detection of Cu2+ Ions

Simple, effective, and eco-friendly sugar-based phase-selective gelators were synthesized at a low cost. They showed high gelling ability toward a wide range of solvents at lower concentrations (minimum gelation concentration ∼0.3%). Preliminary tests reveal that these low molecular weight organogelators can immediately and phase-selectively gel benzene, toluene, petrol, and kerosene in water at room temperature. We also identified G13 in toluene as the good gelator, and the corresponding organogel proficiently removes water-soluble dyes from their concentrated aqueous solutions. This efficient removal of toxic organic solvents and dyes from water suggests promising applications in removing organic substances from contaminated water resources. The thermoreversible gel exhibits effective rechargeability up to five cycles of burning and gelation, which imply the flame stability of the gel. Interestingly, these compounds had a high detection ability toward Cu²⁺ ions with a state change from gel to the solution. The physical justification for gelation mechanisms and the molecular interaction with metal ions were further confirmed by computational studies.

Carboxylate Group-Based Phase-Selective Organogelators with a pH-Triggered Recyclable Property

Phase-selective organogelators (PSOGs) have recently attracted more attention because of their advantages in handling oil spills and leaked organic solvents. However, it is difficult to separate and recover the organic phase and PSOGs from organic gels due to the strong interaction between them. Aiming to enhance the separation and recovery performance of the organic phase and PSOGs, we synthesized a series of pH-responsive PSOGs by using itaconic anhydride and fatty amines with carbon chain lengths of C₁₂-C₁₈. Here, PSOGs have an excellent gelation ability in that amounts of organic solvents and fuel oil can be solidified at a low concentration (<3 wt %). It is worth noting that these gels are stronger, which is more convenient for removal by a salvage operation. More importantly, compared with traditional organogelators, pH-responsive PSOGs can easily recover the organic phase and fuel oil with an adjustment of the pH without extraction or distillation. Because of the transformation between the hydrophilicity and hydrophobicity of PSOGs by pH stimulation, 83.15% PSOGs are recovered in three-cycle experiments. In addition, the recycled PSOGs can be used to realize the removal of the organic phase again. Herein, we find that pH-responsive PSOGs could be used as promising and sustainable materials for separating and recovering organic solvents/oils and PSOGs.

Functional supramolecular gels based on poly(benzyl ether) dendrons and dendrimers

Supramolecular gels, as a fascinating and useful class of soft materials, constructed from low-molecular-weight gelators via noncovalent interactions have attracted increasing attention in the past few decades. Dendrimers and dendrons are highly branched and monodisperse macromolecules with a well-defined three-dimensional architecture and multiple surface functionalities. In recent years, poly(benzyl ether) dendrimers and dendrons are found to be powerful candidates for constructing gel phase materials in organic or aqueous media due to the advantages of capability of forming multiple noncovalent interactions and significant steric impact. In this Feature Article, we provide a comprehensive overview of recent progress in supramolecular gels involving poly(benzyl ether) dendritic molecules. Firstly, we outline the molecular design strategies of dendritic gelators with an emphasis on the discussion of their gelating units and position in molecular structures. Subsequently, we discuss the potential applications of dendritic gels in light harvesting, stimuli responsive materials, sensors and environmental remediation. In addition, the potential challenges and future perspectives of poly(benzyl ether) dendritic gels have also been discussed. It is hoped that this feature article will attract increasing attention and provide some valuable insights for the future design and evolution of supramolecular gels.

Hydrogel Formation by Glutamic-acid-based Organogelator Using Surfactant-mediated Gelation

Hydrogels formed by low-molecular-weight gelators have reversible sol-gel transition and responsiveness to various stimuli, and are used in cosmetics and drug applications. It is challenging to obtain hydrogels using novel gelators because subtle differences in their molecular architecture affect gelation. Organogelators (which form organogels) are insoluble in water, and their use as hydrogelators has not previously been considered. However, a surfactant-mediated gelation method was reported in which organogelators were solubilized in water by surfactants to form hydrogels using 12-hydroxyoctadecanoic acid. To investigate whether this method can be applied with other organogelators, the formation of hydrogel using a glutamic-acid-based organogelator was studied here. Hydrogels were formed by solubilizing 1:1 mixtures of glutamate-based organogelators, N-lauroyl-L-glutamic acid dibuthylamide, and N-2-ethylhexanoyl-L-glutamic acid dibutylamide in aqueous micellar solutions of anionic surfactant (sodium lauroyl glutamate) and cationic surfactant (cetyltrimethylammonium chloride). The minimum gelation concentration of the hydrogel was ~0.2-0.6 wt%. By changing the molar fraction of cetyltrimethylammonium chloride in the mixed surfactant, either spherical or wormlike micelles were formed. The hydrogel with wormlike micelles had a higher sol-gel transition temperature than that with spherical micelles and formed fine self-assembled fibrillar networks. Additionally, the hydrogel with the spherical micelles was elastic, whereas that with wormlike micelles was viscoelastic, suggesting that networks of the organogelators and wormlike micelles coexisted in the hydrogel from the wormlike micellar solution. Moreover, the hydrogel suppressed the reduction in the storage modulus at higher temperatures compared with the micellar aqueous solution, indicating that the elastic properties of the organogelator networks were maintained at high temperatures. The gel fibers of the hydrogel partially formed a loosely aggregated structure as the temperature increased, the fibers bundled via hydrophobic interactions, and new cross-linking points formed spontaneously. This phenomenon corresponded with an inflection point in the temperature-dependent storage modulus of the hydrogel.

Self-Assembly of Alkylamido Isophthalic Acids toward the Design of a Supergelator: Phase-Selective Gelation and Dye Adsorption

A new series of 5-alkylamido isophthalic acid (ISA) derivatives with varying single and twin alkyl chain lengths were designed and synthesized as potential supramolecular organogelators. 5-alkylamido ISAs with linear or branched alkyl tail-groups of different lengths were effective gelators for low polarity solvents. In particular, among the presented series, a derivative with a branched, 24 carbon atom tail-group behaves as a “supergelator” with up to twenty organic solvents forming gels that are highly stable over time. The gelation behavior was analyzed using Hansen solubility parameters, and the thermal stability and viscoelastic properties of select gels were characterized. Microscopy, spectroscopy, powder X-ray diffraction, and computer modeling studies were consistent with a hierarchical self-assembly process involving the formation of cyclic H-bonded hexamers via the ISA carboxylic acid groups, which stack into elementary fibers stabilized by H-bonding of the amide linker groups and π–π stacking of the aromatic groups. These new nanomaterials exhibited potential for the phase-selective gelation of oil from oil–water mixtures and dye uptake from contaminated water. The work expands upon the design and synthesis of supramolecular self-assembled nanomaterials and their application in water purification/remediation.

Design and Synthesis of α-Anomeric Diacetylene-Containing Glycosides as Photopolymerizable Molecular Gelators

Glycolipids with diacetylene functional groups are fascinating compounds with many practical uses. Among these, diacetylene-containing gelators are especially important because they can form photopolymerizable gels, which are useful stimuli-responsive materials. Inspired by the unique properties of diacetylene-containing gelators and to understand the structural influences especially the location of the diacetylene functional groups on the self-assembling properties, a series of 15 novel N-acetyl-d-glucosamine derivatives with the diacetylene functional group introduced at the anomeric position were designed and synthesized. The diacetylene function is attached to the sugar through α-glycosylation with the distance from the anomeric oxygen being varied from one, two, and three methylene groups, and the other side contains hydroxyl, carboxyl, phenyl, and alkyl substituents. Remarkably, all compounds can form self-assembled gels in one or more selected solvents. A majority of these synthesized diacetylene glycosides are effective gelators for ethanol/water (v/v 1:1), dimethyl sulfoxide/water (v/v 1:1), and toluene, and one compound also formed a hydrogel at 1.0 wt %. Typically, these glycosides form gels that are photopolymerizable to afford red-colored gels. Scanning electronic microscopy indicated that the gelators formed helices, fibers, and planar sheet-like morphologies. The chemical structures of the derivatives affected their gelation properties and responses to UV treatment. The carboxylic acid-functionalized derivative 17 was able to immobilize basic solutions and form transparent gels. We expect that these diacetylene glycosides especially the hydroxyl and carboxylic acid derivatives will be useful as stimuli-responsive glycolipids for biomedical research.

Solvent-Modulated Chiral Self-Assembly: Selective Formation of Helical Nanotubes, Nanotwists, and Energy Transfer

As the medium for self-assembly processes, solvents strongly influence the supramolecular assemblies via specific solute-solvent interactions, which may result in effective modulation of properties, self-assembled nanostructures, and functions through varying the solvent. Here, two kinds of pyridine-cyanostilbene functionalized chiral amphiphiles (l/d-PyPhG and l-PyG) were designed, and their self-assembly behaviors in different solvents were investigated. It was found that both amphiphiles formed gels in dimethyl sulfoxide (DMSO) and self-assembled into right-handed nanotwists, while they formed suspensions in ethanol consisting of left-handed nanotubes. Although the molecular chirality in the compounds remained unchanged in the two solvents, the nanoassemblies showed opposite handedness at the nanoscale together with opposite circular dichroism (CD) and circularly polarized luminescence (CPL) signals. Furthermore, when the amphiphiles were co-assembled with an achiral dye, it was found that efficient energy transfer took place in the systems composed of nanotubes rather than those composed of nanotwists. Therefore, by assembling molecules with the same molecular chirality in different solvents, a selective formation of helical nanotubes or nanotwists and the regulation of handedness as well as energy transfer efficiency were achieved.

Ditriphenylenothiophene butterfly-shape liquid crystals. The influence of polyarene core topology on self-organization, fluorescence and photoconductivity

Two series of regio-isomeric mesomorphous, luminescent and conductive compounds, based on a ditriphenylenothiophene core (α/β-DTPT), were successfully synthesized by the Suzuki–Miyaura cross-coupling/Scholl cyclo-dehydrogenation reactions tandem.

Quinoline-cored Poly(Aryl Ether) Dendritic Organogels with Multiple Stimuli-Responsive and Adsorptive Properties

Functional supramolecular gel materials have potential applications in sensors, optical switches, artificial antennae, drug delivery and so on. In this paper, quinoline-cored poly(aryl ether) dendritic organogelators were designed, synthesized and fully characterized. The gelation behaviour of the dendritic organogelator was tested in organic solvents, mixed solvents and ionic liquids. The dendron Q-G1 was found to be an efficient and versatile organogelator toward various apolar and polar organic solvents with the critical gelation concentrations (CGCs) approaching 1.2×10^-2  mol/L, indicating one dendritic organogelator could immobilize 1.2×10³ solvent molecules in the organogel network. Interestingly, these dendrons exhibited excellent gel formation in ionic liquids. Notably, these dendritic organogels were found to display multiple stimuli-responsive properties toward external stimuli including heat, ultrasound and shear stress, with a reversible sol-gel phase transition. In addition, the dendritic organogel could effectively adsorb heavy metals and organic dyes. The removal rate of Pb²⁺ was up to 20% and the adsorption rate for Rhodamine B was as high as 89%.

Fine-Tuning of Molecular Structures to Generate Carbohydrate Based Super Gelators and Their Applications for Drug Delivery and Dye Absorption

Carbohydrate-based low molecular weight gelators (LMWGs) exhibit many desirable properties making them useful in various fields including applications as drug delivery carriers. In order to further understand the structural connection to gelation properties, especially the influence of halide substitutions, we have designed and synthesized a series of para-chlorobenzylidene acetal protected D-glucosamine amide derivatives. Fifteen different amides were synthesized, and their self-assembling properties were assessed in multiple organic solvents, as well as mixtures of organic solvents with water. All derivatives were found to be gelators for at least one solvent and majority formed gels in multiple solvents at concentrations lower than 2 wt%. A few derivatives rendered remarkably stable gels in aqueous solutions at concentrations below 0.1 wt%. The benzamide 13 formed gels in water and in EtOH/H2O (v/v 1:2) at 0.36 mg/mL. The gels were characterized using optical microscopy and atomic force microscopy, and the self-assembly mechanism was probed using variable temperature 1H-NMR spectroscopy. Gel extrusion studies using H2O/DMSO gels successfully printed lines of gels on glass slides, which retained viscoelasticity based on rheology. Gels formed by the benzamide 13 were used for encapsulation and the controlled release of chloramphenicol and naproxen, as well as for dye removal for toluidine blue aqueous solutions.

Helicenes at Air/Water Interface: Spreading Film and Metal Ion Induced a Helical Ring Nanostructure

Two enantiomeric hydrohelicenes containing a hydroxyl group and a π-conjugated nonplanar structure are assembled at the air/water interface. These molecules are found to form spreading films with well-defined surface pressure-area isotherms. Upon transferring the spreading film onto the mica surface, porous nanostructures are observed. The spreading film can be transferred onto solid substrates by the Langmuir-Schaefer (LS) method and the transferred LS films display optical activity as revealed by the circular dichroism (CD) spectra. The P- and M-hydrohelicene enantiomers showed mirrored CD spectra, suggesting that the chirality of the LS films was controlled by molecular chirality. When these molecules are spread on the aqueous solution containing metal ions such as Ag⁺, Cu²⁺, and Zn²⁺, a clear twisted ring nanostructure, which is similar to the Möbius strip, is observed. It is suggested that the interaction between the hydroxyl groups of helicenes and metal ions induced such a ring nanostructure.

Varying the hydrophobic spacer to influence multicomponent gelation

Mixing low molecular weight gelators (LMWGs) shows promise as a means of preparing innovative materials with exciting properties. Here, we investigate the effect of increasing hydrophobic chain length on the properties of the resulting multicomponent systems which are capable of showing ambidextrous phase behaviour on pH perturbation.

Construction of a hydroxide responsive C3-symmetric supramolecular gel for controlled release of small molecules

A C3-symmetric acylhydrazone-based low molecular weight gelator (BHTP) bearing three pyridine units was synthesized and it was found to form a stable supramolecular gel in the mixture solvent of DMSO-H2O. The morphology of the gel as observed by FE-SEM showed a dense sheet structure. Hydrogen bonding and π-π stacking between the gelators were determined as the non-covalent interactions for the gelation, which were investigated thoroughly using XRD, UV-Vis, 1H NMR and FT-IR instruments. BHTP could form pH tolerant supramolecular gels in the widest range of pH values from 1 to 11. The DMSO-H2O (v : v = 1 : 1) gel exhibited selective response to OH- over a series of other anions through the color change from a white gel to a yellow solution, and the OH- response mechanism was proved by 1H NMR experiments. In solution, the lowest detection limit of BHTP for OH- was calculated to be as low as 1.62 × 10-7 M via UV-Vis titration experiments. Finally, encapsulation and controlled release of small molecules such as rhodamine B, crystal violet and methyl orange have been successfully carried out, demonstrating the potential for drug delivery application of this C3-symmetric supramolecular gel. This work opens a novel avenue for the preparation of supramolecular gel-based multiple functional smart materials.

Rational Design of Diphenyldiacetylene-Based Fluorescent Materials Enabling a 365-nm Light-Initiated Topochemical Polymerization

Photopolymerization of diacetylenes usually requires stringent reaction conditions like high energy irradiation of 254-nm light or even γ-rays, which are generally harmful to the human body and thus mild conditions with lower energy irradiation are required. In this study, different diphenyldiacetylene (DPDA) derivatives were rationally designed followed by the investigation of their photopolymerization behavior. It was found that the para-substituted amino groups could render the absorption band of DPDA bathochromically shifted, ensuring a 365-nm light wavelength coverage. On this basis, an organogel system was constructed by chemically modifying cholesteryl and lipoic acid onto the DPDA moiety in aromatic solvents. Such uniform self-assemblies further facilitated to a rather high degree of polymerization by 365-nm irradiation. As a kind of fluorescent materials, the whole polymerization process of this system can be visualized by a photoluminescent signal.

Naphthalene diimides: perspectives and promise

In this review, we describe the developments in the field of naphthalene diimides (NDIs) from 2016 to the presentday. NDIs are shown to be an increasingly interesting class of molecules due to their electronic properties, large electron deficient aromatic cores and tendency to self-assemble into functional structures. Almost all NDIs possess high electron affinity, good charge carrier mobility, and excellent thermal and oxidative stability, making them promising candidates for applications in organic electronics, photovoltaic devices, and flexible displays. NDIs have also been extensively studied due to their potential real-world uses across a wide variety of applications including supramolecular chemistry, sensing, host-guest complexes for molecular switching devices, such as catenanes and rotaxanes, ion-channels, catalysis, and medicine and as non-fullerene accepters in solar cells. In recent years, NDI research with respect to supramolecular assemblies and mechanoluminescent properties has also gained considerable traction. Thus, this review will assist a wide range of readers and researchers including chemists, physicists, biologists, medicinal chemists and materials scientists in understanding the scope for development and applicability of NDI dyes in their respective fields through a discussion of the main properties of NDI derivatives and of the status of emerging applications.

Inversing supramolecular chirality and boosting circularly polarized luminescence of pyrene moieties via a gel matrix

Alkyl-substituted l/d-glutamide derivatives (L/D-SG) were designed as gelators to fabricate host gel matrices. Pyrene-appended l/d-glutamide derivatives (Py-LG/Py-DG) were employed as guest luminophores to investigate chiral packing and emission behavior in gel matrices. It was found that Py-LG and Py-DG are prone to form P- and M-chirally packed assemblies in DMSO gels, respectively. However, the chiral packing was inversed, and CPL was boosted after Py-LG/Py-DG was embedded in the L/D-SG gel matrix. M-chiral packing together with left-handed excimer emission ((-)-CPL) was observed in the Py-LG immobilized L-SG gel matrix, while P-chiral packing together with right-handed excimer emission ((+)-CPL) was found in the Py-DG immobilized L-SG gel matrix. It is more interesting to find that the molecular chirality of the matrix gelator did not affect the supramolecular chirality of pyrene assemblies. Either l or a d-matrix gelator can inverse the supramolecular chirality of the pure gel, but did not follow the chirality of the matrix. It was found that the gel matrix converts intralayer pyrene-pyrene (Py-Py) packing in the pure pyrene gel to interlayer Py-Py packing, thus giving an opposite chirality. The study not only deepened our understanding of the supramolecular chirality transfer but also unveiled the effects of an inert gel matrix in regulating the chiroptical properties.

Stimuli responsive dynamic transformations in supramolecular gels

Supramolecular gels are formed by the self-assembly of small molecules under the influence of various non-covalent interactions. As the interactions are individually weak and reversible, it is possible to perturb the gels easily, which in turn enables fine tuning of their properties. Synthetic supramolecular gels are kinetically trapped and usually do not show time variable changes in material properties after formation. However, such materials potentially become switchable when exposed to external stimuli like temperature, pH, light, enzyme, redox, and chemical analytes resulting in reconfiguration of gel matrix into a different type of network. Such transformations allow gel-to-gel transitions while the changes in the molecular aggregation result in alteration of physical and chemical properties of the gel with time. Here, we discuss various methods that have been used to achieve gel-to-gel transitions by modifying a pre-formed gel material through external perturbation. We also describe methods that allow time-dependent autonomous switching of gels into different networks enabling synthesis of next generation functional materials. Dynamic modification of gels allows construction of an array of supramolecular gels with various properties from a single material which eventually extend the limit of applications of the gels. In some cases, gel-to-gel transitions lead to materials that cannot be accessed directly. Finally, we point out the necessity and possibility of further exploration of the field.

Chirality, Gelation Ability and Crystal Structure: Together or Apart? Alkyl Phenyl Ethers of Glycerol as Simple LMWGs

Chiral recognition plays an important role in the self-assembly of soft materials, in particular supramolecular organogels formed by low molecular weight gelators (LMWGs). Out of 14 pairs of the studied racemic and enantiopure samples of alkyl-substituted phenyl ethers of glycerol, only eight enantiopure diols form the stable gels in nonane. The formation of gels from solutions was studied by polarimetry, and their degradation with the formation of xerogels was studied by the PXRD method. The revealed crystalline characteristics of all studied xerogels corresponded to those for crystalline samples of the parent gelators. In addition to those previously investigated, crystalline samples of enantiopure para-n-alkylphenyl glycerol ethers [alkyl = pentyl (5), hexyl (6), heptyl (7), octyl (8), nonyl (9)] and racemic 3-(3,5-dimethylphenoxy)propane-1,2-diol (rac-14) have been examined by single crystal X-ray diffraction analysis. Among 22 samples of compounds 1–14 studied by SC-XRD, seven different types of supramolecular motifs are identified, of which only two are realized in crystals of supramolecular gelators. An attempt was made to relate the ability to gel formation with the characteristics of the supramolecular motif of a potential gelling agent, and the frequency of formation of the motif, required for gelation, with the chiral characteristics of the sample.

Switchable Circularly Polarized Luminescence in Supramolecular Gels through Photomodulated FRET

While the tremendous deal of efforts has been dedicated to the design and fabrication of materials with circularly polarized luminescence (CPL), the development of the chiroptical switch between different CPL signals is one of the important routes toward its application. Here, we prepared a supramolecular gel from the coassemblies containing a chiral gelator (9-fluoren-methoxycarbonyl-functionalized glutamate derivatives, FLG), a fluorescent molecule [(rhodamine B, RhB) or (2',7'-dichlorofluorescein sodium salt, DCF)], and a photochromic molecule [1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)-3,3,4,4,5,5-hexafluoro-1-cyclopentene, DAE], thus constructing photomodulated switchable CPL soft materials. It was found that FLG could form supramolecular gel in ethanol and self-assemble into left-handed twisted nanostructures. During the formation of a co-gel with RhB (or DCF) and DAE, the chirality of FLG could be effectively transferred to both the fluorescent and photochromic components, which induced them with chiroptical properties including CPL and circular dichroism (CD). DAE undergoes a reversible transition between the achromatous open state and the dark purple closed state in the co-gel under alternating irradiation with UV and visible light. During such a process, an intermolecular Förster resonance energy transfer (FRET) behavior from fluorescent RhB to ring-closed DAE caused the emission quenching of RhB, which led to CPL silence of RhB in the co-gel. Subsequent irradiation with visible light caused the restoration of the emission and CPL activity with the restored open state. These changes could be repeated many times upon alternate UV and visible irradiation. Therefore, a reversible CPL switch was fabricated in supramolecular gels through the photomodulated FRET process.

Pyromellitic-Based Low Molecular Weight Gelators and Computational Studies of Intermolecular Interactions: A Potential Additive for Lubricant

Low molecular weight gelators (LMWG) have been extensively explored in many research fields due to their unique reversible gel-sol transformation. Intermolecular interactions between LMWG are known as the main driving force for self-assembly. During this self-assembly process, individually analyzing the contribution difference between various intermolecular interactions is crucial to understand the gel properties. Herein, we report 2,5-bis(hexadecylcarbamoyl)terephthalic acid (BHTA) as a LMWG, which could efficiently form a stable organogel with n-hexadecane, diesel, liquid paraffin, and base lubricant oil at a relatively low concentration. To investigate the contribution difference of intermolecular interactions, we first finished FT-IR spectroscopy and XRD experiments. On the basis of the d-spacing, a crude simulation model was built and then subjected to molecular dynamics (MD) simulations. Then, we knocked out the energy contribution of the H-bonding interactions and π-π stacking, respectively, to evaluate the intermolecular interactions significantly influencing the stability of the gel system. MD simulations results suggest that the self-assembly of the aggregates was mainly driven by dense H-bonding interactions between carbonyl acid and amide moieties of BHTA, which is consistent with FT-IR data. Moreover, wave function analysis at a quantum level suggested these electrostatic interactions located in the middle of the BHTA molecule were surrounded by strong dispersion attraction originating from a hydrophobic environment. Furthermore, we also confirmed that 2 wt % BHTA was able to form gel lubricant with 150BS. The coefficient of friction (COF) data show that the gel lubricant has a better tribological performance than 150BS base lubricant oil. Finally, XPS was performed and offered valuable information about the lubrication mechanism during the friction.

Recently Developed Carbohydrate Based Gelators and Their Applications

Carbohydrate based low molecular weight gelators have been an intense subject of study over the past decade. The self-assembling systems built from natural products have high significance as biocompatible materials and renewable resources. The versatile structures available from naturally existing monosaccharides have enriched the molecular libraries that can be used for the construction of gelators. The bottom-up strategy in designing low molecular weight gelators (LMWGs) for a variety of applications has been adopted by many researchers. Rational design, along with some serendipitous discoveries, has resulted in multiple classes of molecular gelators. This review covers the literature from 2017-2020 on monosaccharide based gelators, including common hexoses, pentoses, along with some disaccharides and their derivatives. The structure-based design and structure to gelation property relationships are reviewed first, followed by stimuli-responsive gelators. The last section focuses on the applications of the sugar based gelators, including their utilization in environmental remediation, ion sensing, catalysis, drug delivery and 3D-printing. We will also review the available LMWGs and their structure correlations to the desired properties for different applications. This review aims at elucidating the design principles and structural features that are pertinent to various applications and hope to provide certain guidelines for researchers that are working at the interface of chemistry, biochemistry, and materials science.

Self-assembly gel-based dynamic response system for specific recognition of N-acetylneuraminic acid

Sialic acids located at the terminal end of glycans are densely attached to cell surfaces and play crucial and distinctive roles in a variety of physiological and pathological processes, such as neural development, cell-cell interactions, autoimmunity and cancers. However, due to the subtle structural differences of sialic acid species and the complicated composition of glycans, the precise recognition of sialylated glycans is difficult. Here, a fluorescent dynamic response system based on a pyrene-conjugated histidine (PyHis) supramolecular gel is proposed. Driven by π-π stacking and intermolecular hydrogen bonds, PyHis exhibits a strong self-assembly ability and forms stable gels. It is found that introduction of N-acetylneuraminic acid (a typical sialic acid) can prevent this self-assembly process, whereas other monosaccharides or sialic acid analogs have no significant effect on it. Interestingly, a sialylated glycan also has a remarkable inhibitory effect on the gel formation, which highlights the high selectivity of the gel dynamic response system. Analysis of the mechanism reveals that the sialic acid or sialylated glycan can interact closely with two PyHis molecules stacked together in the assemblies via hydrogen bonding interactions, thereby preventing the ordered accumulation of the gelators. It is worth noting that the high-efficiency sialic acid recognition effect is not observed at the single molecule level but at the supramolecular level, indicating the unique superiority of the supramolecular self-assembly system in biomolecular recognition and response. This work shows the promising prospects of using supramolecular gels in assembly engineering, regenerative medicine, tumour cell sorting and cancer diagnosis.

Synthesis of Dendritic Glycoclusters and Their Applications for Supramolecular Gelation and Catalysis

Glycoclusters with three, four, and six arms of glycosyl triazoles were designed, synthesized, and characterized. The self-assembling properties of these molecules and their catalytic activity as ligands in copper-catalyzed azide and alkyne cycloaddition (CuAAC) reactions were studied. The compounds with a lower number of branches exhibit excellent gelation properties and can function as supramolecular gelators. The resulting gels were characterized using optical microcopy and atomic force microscopy. The glycoconjugates containing six branches showed significant catalytic activity for copper sulfate mediated cycloaddition reactions. In aqueous solutions, 1 mol % of glycoclusters to substrates was efficient at accelerating these reactions. Several trimeric compounds were found to be capable of forming co-gels with the catalytically active hexameric compounds. Using the organogels formed by the glycoconjugates as supramolecular catalysts, efficient catalysis was demonstrated for several CuAAC reactions. The metallogels with CuSO₄ were also prepared as gel columns, which can be reused for the cycloaddition reactions several times. These include the preparation of a few glycosyl triazoles and aryl triazoles and isoxazoles. We expect that these sugar-based soft biomaterials will have applications beyond supramolecular catalysis for copper-catalyzed cycloaddition reactions. They may also be useful as ligands or gel matrixes for other metal-ion catalyzed organic reactions.