Search Results (337)

Macrocyclic organic nanostructures have emerged as crucial components of functional supramolecular materials owing to their unique structural and chemical features, such as their distinctive “infinite” cyclic topology and tunable topology-dependent properties, attracting significant recent attention. However, the controlled synthesis of macrocyclic compounds with well-defined compositions and geometries remains a formidable challenge. On-surface synthesis, capable of constructing nanostructures with atomic precision on various substrates, has become a frontier technique for exploring novel macrocyclic architectures. This review summarizes the recent advances in the on-surface synthesis of macrocycles. It focuses on analyzing the synthetic mechanisms and conformational characterization of macrocycles formed through diverse bonding interactions, including both covalent and non-covalent linkages. This review elucidates the intricate interplay between the thermodynamic and kinetic factors governing macrocyclic structure formation across these bonding types and clarifies the critical influence of the reaction temperature and external conditions on the cyclization efficiency. Ultimately, this study offers design strategies for the precise on-surface synthesis of larger and more flexible macrocyclic compounds. Full article

Polyoxometalate (POM)-type supramolecular materials have unique structures and hold immense potential for development in the fields of biomedicine, information storage, and electrocatalysis. In this study, (NH₄)₃ [AlMo₆O₂₄H₆]·7H₂O was employed as a polyacid anion template, pentacyclic imidazole molecules served as organic ligands, and the moderate-temperature hydrothermal and natural evaporation methods were used in combination for the design and synthesis of two octamolybdenum-oxo cluster (homopolyacids containing molybdenum-oxygen structures as the main small-molecular structures)-based organic–inorganic hybrid compounds, [(C₃N₂H₅)(C₃N₂H₄)][(β-Mo₈O₂₆H₂)]_0.5 (1) and {Zn(C₃N₂H₄)₄}{[(γ-Mo₈O₂₆)(C₃N₂H₄)₂]_0.5}·2H₂O (2). Structural and property characterization revealed that both compounds crystallized in the P-1 space group with relatively stable three-dimensional structures under the action of hydrogen bonding. Upon temperature stimulation, the [Zn(C₃N₂H₄)₄]²⁺ cation and water molecules in 2 exhibited obvious oscillations, leading to significant dielectric anomalies at approximately 250 and 260 K when dielectric testing was conducted under heating conditions. Full article

Boronic acids are an important class of molecules diversely used in organic synthesis, catalysis, medicinal chemistry, and for the design of functional materials. Particularly, aryl boronic acids in the solid state are known to exhibit pharmaceutical and photoluminescent properties for antimicrobial, sensing, and drug delivery applications. Furthermore, the phenazine molecule is known for its diverse pharmacological properties, including antibiotic activity. In the case of molecular crystalline solids, it is well established that understanding noncovalent interactions remains key to designing or engineering their functional properties. While both aryl boronic acids and phenazine molecules individually represent an important class of compounds, their co-assembly in the crystalline state is of interest within the context of supramolecular chemistry and crystal engineering. Herein, we report the supramolecular features of two newly synthesized cocrystals, which are composed of para-F/CF₃-substituted phenylboronic acids, respectively, and phenazine, as demonstrated by structure analysis by single-crystal X-ray diffraction. Full article

Nanomaterials with large specific surface area (SSA) have emerged as pivotal platforms for energy storage and environmental remediation, primarily due to their enhanced active site exposure, improved mass transport capabilities, and superior interfacial reactivity. Among them, polymeric carbon nitride (g-C₃N₄) has garnered significant attention in energy and environmental applications owing to its visible-light-responsive bandgap (~2.7 eV), exceptional thermal/chemical stability, and earth-abundant composition. However, the practical performance of g-C₃N₄ is fundamentally constrained by intrinsic limitations, including its inherently low SSA (<20 m²/g via conventional thermal polymerization), rapid recombination of photogenerated carriers, and inefficient charge transfer kinetics. Notably, the theoretical SSA of g-C₃N₄ reaches 2500 m²/g, yet achieving this value remains challenging due to strong interlayer van der Waals interactions and structural collapse during synthesis. Recent advances demonstrate that state-of-the-art strategies can elevate its SSA to 50–200 m²/g. To break this surface area barrier, advanced strategies achieve SSA enhancement through three primary pathways: pre-treatment (molecular and supramolecular precursor design), in process (templating and controlled polycondensation), and post-processing (chemical exfoliation and defect engineering). This review systematically examines controllable synthesis methodologies for high-SSA g-C₃N₄, analyzing how SSA amplification intrinsically modulates band structures, extends carrier lifetimes, and boosts catalytic efficiencies. Future research should prioritize synergistic multi-stage engineering to approach the theoretical SSA limit (2500 m²/g) while preserving robust optoelectronic properties. Full article

This work presents the synthesis and structural characterization of a novel type of biscyclometalated Ir(III) complex, which is equipped with two iodoethynyl moieties on its 2,2′-bipyridine (bpy) ligand. Iodoethynyl moieties represent prominent donor systems for the formation of supramolecular structures via halogen bonding (X-bonding). The synthesis of bis(2-phenylpyridinato)-[4,4′-bis(iodoethynyl)-2,2′-bipyridine]iridium(III) hexafluorophosphate, (2)(PF₆), is straightforward and involves post-complexation iodination, thus expanding the already rich toolbox for performing “chemistry on the complex”. The formation of the iodoethynyl moieties was unequivocally proven by ¹H-NMR spectroscopy, ESI-TOF mass spectrometry, and single-crystal XRD analysis. Full article

Precise control over molecular dispersity and supramolecular assembly is essential for designing nanostructures with targeted properties and functionalities. In this study, we explore the impact of molecular dispersity in BTA-oligo(AA)₃ oligomers on the formation and structural organization of Au nanomaterials in an aqueous system. Discrete and polydisperse BTA-oligo(AA)₃ samples are systematically synthesized and characterized to evaluate their role as templates for nanostructure formation. UV-vis spectroscopy and TEM analyses reveal distinct differences in the resulting nanostructures. Specifically, discrete oligomers facilitate the formation of well-defined, interconnected Au nanonetworks with high structural uniformity, even at elevated concentrations. In contrast, polydisperse oligomers facilitated the formation of isolated Au nanoparticles with limited control over morphology and connectivity. These differences are attributed to the greater molecular uniformity and enhanced self-assembly capabilities of the discrete oligomers, which serve as effective templates for directing Au precursor organization and reduction into ordered nanostructures. This study provides mechanistic insight into how molecular dispersity affects the templating and assembly of gold nanomaterials. The findings offer a promising strategy for developing tailored nanostructures with interconnected morphologies and controlled optical and structural properties, paving the way for advanced applications. Full article

A single-molecule magnet (SMM) is a molecule that functions as a magnet. SMMs can be explored not only for emerging technology but also the fundamental science of their quantum nature, nanometer sizes, and their ease of engineering. This review encompasses the state-of-the-art experiments and theories developed so far for SMMs. We briefly explore their experimental synthesis and characterization. In the experimental synthesis, we cover ‘Click Chemistry’ and supramolecular chemistry. The main experimental characterizations comprise superconducting quantum interference devices, electron paramagnetic resonance, neutron scattering, and X-ray magnetic circular dichroism. The theoretical and computational works based on the density functional theory, the post-Hartree–Fock methods, and the theory of open quantum systems are discussed. Moreover, we exemplify the numerous promising research areas for SMMs by discussing quantum technologies. We envision a brilliant future for the fundamental research and emerging applications of SMMs. Full article

Cellulose is a sustainable biopolymer, being renewable and abundant, non-toxic, biodegradable, and easily functionalizable. However, the development of hydrogels for tissue engineering applications presents significant challenges that require interdisciplinary expertise, given the intricate and dynamic nature of the human body. This paper delves into current research focused on creating advanced cellulose-based hydrogels with tailored mechanical, biological, chemical, and surface properties. These hydrogels show promise in healing, regenerating, and even replacing human tissues and organs. The synthesis of these hydrogels employs a range of innovative techniques, including supramolecular chemistry, click chemistry, enzyme-induced crosslinking, ultrasound, photo radiation, high-energy ionizing radiation, 3D printing, and other emerging methods. In the realm of tissue engineering, various types of hydrogels are explored, such as stimuli-responsive, hybrid, injectable, bio-printed, electrospun, self-assembling, self-healing, drug-releasing, biodegradable, and interpenetrating network hydrogels. Moreover, these materials can be further enhanced by incorporating cell growth factors, biological molecules, or by loading them with cells or drugs. Looking ahead, future research aims to engineer and tailor hydrogels to meet specific needs. This includes exploring safer and more sustainable materials and synthesis techniques, identifying less invasive application methods, and translating these studies into practical applications. Full article

This article discloses the synthesis of four new positional isomeric zwitterionic ligands exhibiting semi-flexible and flexible characteristics—n-pyridinium-1,2,3-triazole-4-carboxy-5-Acetate (n-PTCA), and n-methylpyridinium-1,2,3-triazole-4-carboxy-5-Acetate (n-MPTCA; where n = 3, 4)—which were derived from an aqueous solution of the corresponding sodium salts in an acidic medium (HCl). These compounds are successfully synthesized and characterized with FT-IR and multinuclear NMR spectroscopy; likewise, proper single crystals are obtained for each compound. All compounds adopt zwitterionic forms in the solid state, which are stabilized via intermolecular proton transfer processes involving HCl and solvent molecules. A single-crystal X-ray analysis revealed how positional isomerism and molecular flexibility influence the supramolecular topology. Specifically, 3-PTCA and 4-PTCA exhibit isomorphic hydrogen bond networks, while 3-MPTCA and 4-MPTCA display distinct packing motifs, attributed to the presence of a methylene spacer between the pyridinium and triazole rings. The Hirshfeld surface analysis quantitatively confirmed the dominance of O···H/H···O and N···H/H···N interactions in the solid-state architecture. These strong hydrogen-bonding networks are indicative of the potential proton-conductive behavior in the crystalline state, positioning these compounds as promising candidates for applications in proton-conducting materials. The structural insights gained underscore the pivotal role of molecular topology in tailoring crystal packing, with implications for the rational design of zwitterionic ligands in functional materials, including MOFs and coordination polymers. The calculated HOMO-LUMO energy gaps reveal a significant electronic variability among the ligands, influenced primarily by the positional isomerism and structural flexibility introduced by the methylene spacer. Full article

Visible-light photoredox catalysis using biacetyl (BA) as a low-cost photosensitizer enables the efficient formation of triarylethylenes (TAEs) via a Mizoroki–Heck-type coupling. The reaction proceeds efficiently in acetonitrile upon blue LED irradiation under anaerobic conditions. Alternatively, supramolecular viscoelastic gels have also been explored as reaction media, allowing the possibility of working under aerobic atmosphere. Mechanistic investigations by means of transient absorption spectroscopy and quenching experiments support a charge-separated intermediate pathway. Reaction quantum yield measurements further validate the efficiency of BA, demonstrating its potential as an alternative to transition-metal catalysts. Overall, this work presents a sustainable and scalable strategy for TAEs synthesis, integrating photoredox catalysis with soft material engineering. These findings pave the way for broader applications in green chemistry and functional materials. Full article

The precise construction and programmable assembly of structures with specific topologies remain persistent challenges in crystal engineering, primarily constrained by the limited availability of building blocks. Utilizing a synergistic approach that combines an in situ-formed concave polyoxovanadate (POV) cluster {VV₄} with specifically designed 120° ditopic carboxylic acid bridging ligands, we successfully synthesized a series of wine-rack-type supramolecular macrocycles characterized by the general formula [(V₅O₉Cl)₄(L)₈]⁸⁻. The experimental results demonstrate that the introduction of sulfonic acid groups enables controlled structural extension into 1D chain and 2D layer architectures, manifesting the unique advantages of POV-based wine-rack units in constructing framework-based porous materials. This work significantly contributes to the structural diversity of wine-rack-type supramolecular architectures while simultaneously highlighting the great potential of polyoxometalate-driven supramolecular assemblies in materials science. Full article

Seeking a supramolecular chiral system induced by trace chiral molecules instead of traditional complex and expensive chiral ligands to achieve high yield or ee value conversion of the products is of great significance in asymmetric synthesis but still remains a challenge. Herein, two types of double helical supramolecular chiral systems, (M)-Helix and (P)-Helix, with opposite chiral optics were constructed in situ using tyrosine-functionalized pillar[5]arene as inducers. These systems exhibit chiroptical stability and enable remarkable chirality amplification from 7 mol% chiral seeds. When applied to intermolecular olefin cyano-trifluoromethylation, (M)-Helix exhibits remarkable catalytic efficiency (yield up to 89%), whereas (P)-Helix achieves higher enantioselectivity (ee up to 84%). This research will provide new ideas for supramolecular chiral catalysts in organic asymmetric catalysis applications. Full article

In this review article the synthesis and solid state structure of squaramide/squarate based metal–organic frameworks (MOFs) are analyzed and discussed. In detail, a thorough search in the literature revealed the successful utilization of these two organic molecules as MOF building blocks capable of catalyzing (i) water splitting reactions, (ii) electrocatalytic oxygen evolution reactions, and (iii) Michael addition reactions. Additionally, some of the highlighted examples also utilized these two molecular synthons to compose MOFs exhibiting gas adsorbent properties, concretely for capturing propadiene and propylene. In each of the selected examples a theoretical study of the noncovalent interactions (NCIs) established between the squaramide/squarate-based MOF and the guest molecules trapped inside was carried out, providing additional information regarding the strength of the MOF–guest interactions, which certainly influence the catalytic/adsorbent capabilities of these materials. We believe that the examples collected herein will be useful for those scientists working in the fields of supramolecular chemistry, crystal engineering, catalysis, and materials science by providing a retrospective guide on the role of squaramide and squarate in the formation of MOFs. Full article

Introduction. Many pharmacological properties of dipyridamole (DIP) are associated with its ability to inhibit phosphodiesterases (PDEs). Actually, DIP has interesting properties like antiviral for influenza, SARS-2 COVID-19, and herpesviruses. Our research aimed to design and synthesize the dynamic combinatorial DIP derivatives with more pronounced inhibiting properties in relation to PDE and to carry out the HPLC analysis of the resulting combinatorial derivatives of DIP. This study is aimed at investigating the effect of the dynamic derivative of dipyridamole (DDD) on intestinal dysbiosis syndrome in mice caused by streptomycin against the background of cyclophosphamide-induced cellular immunodeficiency. Materials and methods. For the synthesis of a dynamic combinatorial derivative of dipyridamole, we used a molecular dynamic method for drug design and combinatorial acylation of dipyridamole by succinic and acetic anhydride in different molar ranges of acylation agents. Combinatorial derivatives were analyzed using gradient HPLC with a UV detector. Also, derivatives established the inhibition ability for phosphodiesterase by the spectrophotometric method. Also, we used an in vivo mouse model with immunodeficiency caused by cyclophosphamide for pharmacological study. Results and discussion. Molecular modeling suggests that 18 different dipyridamole derivatives can self-assemble into a stable supramolecular structure with lower total energy. Specific combinatorial molar ratios of the synthesis components were necessary to create a new supramolecular compound with enhanced pharmacological properties. The inhibition of phosphodiesterase in such a dynamic combinatorial derivative already appeared at a concentration of 0.05 μM. In mice with colitis caused by streptomycin treatment, the administration of DDD per os resulted in an antidiarrheal effect and prevention of the animals’ weight loss. Given the cyclophosphamide-induced immunosuppression and streptomycin-associated diarrhea, immunity was completely restored only under the action of DDD. Conclusions. The most effective dipyridamole derivative for phosphodiesterase inhibition was formed only if the number of different derivatives in solution was maximum and consisted of all 18 molecules. With other quantities of modifiers, there was no qualitative change in the inhibitory activity of the combinatorial mixture against phosphodiesterase. According to all parameters, DDD has been proven to be more effective than the pure dipyridamole reference product. Full article

Five new coordination compounds that included three coordination polymers and two supramolecular complexes were obtained by reactions of different cadmium salts (tetrafluoroborate, nitrate, and perchlorate) with dianiline chromophores, 4,4′-diaminodiphenylmethane (ddpm), and 4,4′-diaminodiphenylethane (ddpe). The crystal structures were studied by single-crystal X-ray analysis. The coordination arrays with the ddpm chromophore included {[Cd(OH)(H₂O)(ddpm)₂](BF₄)}_n (1) as a one-dimensional (1D) coordination garland chain, {[Cd(NO₃)(ddpm)₂](H₂O)(NO₃)}_n (2) as a two-dimensional (2D) coordination layer, and [Cd(bpy)₂(ddpm)₂](ddpm)(NO₃)₂ (3) as a supramolecular complex. The products with the ddpe chromophore were identified as {[Cd(phen)₂(ddpe)](ClO₄)₂}_n (4) in the form of a linear coordination chain and [Cd(phen)₃](ClO₄)₂(ddpe)_0.5(CH₃CN)_0.5 (5) as a supramolecular complex. The extension of coordination arrays in 1, 2, and 4 was achieved via dianiline ligands as bidentate linkers and additionally via bridging of nitrate anions in 2. The diversification of products became possible due to usage of 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) as co-ligands forming the terminal corner fragments [Cd(bpy)₂]²⁺, [Cd(phen)₂]²⁺, and [Cd(phen)₃]²⁺ in 3–5, respectively. The assembling of coordination entities occurred via the interplay of hydrogen bonds with the participation of amino groups, water molecules, and inorganic anions. Two dianilines were powerful luminophores in the crystalline phase, while the photoluminescence in 1–5 was considerably weaker than in the pure ddpm and ddpe luminophores and redistributed along the spectrum. Full article