Search Results (501)

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

The efficient employment of chiral porous organic cages (POCs) for asymmetric catalysis is of great significance. In this work, we have synthesized a chiral N-rich organic cage constructed through chiral (S, S)-1,2-cyclohexanediamine and benzene-1,3,5-tricarbaldehyde utilizing dynamic imine chemistry according to the literature. Following reduction with NaBH₄, the resulting amine-based POCs (RCC3) feature appended chiral diamine moieties capable of coordinating Cu²⁺ cations. This Cu²⁺ coordination provides RCC3 with excellent enantioselectivity as a supramolecular nanoreactor in asymmetric decarboxylative Mannich reactions, providing up to 94% ee of the product. We found that the spatial distribution of chiral amine sites and the coordination of Cu²⁺ in the RCC3 have a significant impact on catalytic activity, especially enantioselectivity. This work provides insights into the structure–function relationship within supramolecular catalytic systems Full article

Four novel crystalline architectures based on benzo[c]cinnolininium trifluoromethanesulonate salts, [C₁₂H₉N₂]⁺[CF₃SO₃]⁻, have been isolated as single-crystals, and their structures have been determined by X-ray diffraction analysis. The formation of the new salts results from reactions involving the dimeric hydroxo di-n-butylstannane trifluoromethanesulfonato complex [n-Bu₂Sn(OH)(H₂O)(CF₃SO₃)]₂ (1) and benzo[c]cinnoline (C₁₂H₈N₂, BCC). Organic salts I, II, III, and IV were crystallized through slow evaporation at room temperature from a mixture of toluene/dichloromethane. The cystallographic structures of I, II, and IV exhibit the presence of monoprotonated benzo[c]cinnolinium cations in interactions with a free benzo[c]cinnoline molecule through N–H···N hydrogen bonding, while for salt III, the monoprotonated cation directly interacts with the CF₃SO₃⁻ anion via an N–H···O interaction. For all four salts, aromatic π-π interactions involving rings of various components (free benzo[c]cinnoline molecule, benzo[c]cinnolinium cation, toluene molecule), combined with weak C–H···O and C–H···F interactions implying the trifluoromethanesulfonate anion, promote the solid-state self-assembly of supramolecular stacks. In parallel to the formation of benzo[c]cinnolinium based-salts, organotin(IV) 1 was converted into a distannoxane compound, ²_∞{[n-Bu₂(μ-OH)SnOSn(μ-η²-O₃SCF₃)n-Bu₂]₂[n-Bu₂(η¹-O₃SCF₃)SnOSn(μ-OH)n-Bu₂]₂} (3), which was also isolated as a single crystal and whose crystallographic structure was previously established by us. Full article

The one-dimensional (1D) Sb(III)-based organic–inorganic hybrid perovskite (AImd)₂¹_∞[SbI₅] (AImd = 1-allylimidazolium) crystallizes in the orthorhombic, centrosymmetric space group Pnma. The structure consists of corner-sharing [SbI₆] octahedra forming 1D chains separated by allylimidazolium cations. Void analysis through Mercury CSD software confirmed a densely packed lattice with a calculated void volume of 1.1%. Integrated quantum theory of atoms in molecules (QTAIM) and non-covalent interactions index (NCI) analyses showed that C–H···I interactions between the cations and the ¹_∞[SbI₅]²⁻ network predominantly stabilize the supramolecular assembly followed by N–H···I hydrogen bonds. The calculated growth morphology (GM) model fits very well to the experimental morphology. UV–Vis diffuse reflectance spectroscopy allowed us to determine the optical band gap to 3.15 eV. Density functional theory (DFT) calculations employing the B3LYP, CAM-B3LYP, and PBE0 functionals were benchmarked against experimental data. CAM-B3LYP best reproduced Sb–I bond lengths, while PBE0 more accurately captured the HOMO–LUMO gap and the associated electronic descriptors. These results support the assignment of an inorganic-to-organic [Sb–I] → π* charge-transfer excitation, and clarify how structural dimensionality and cation identity shape the material’s optoelectronic properties. 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

Arginine plays a critical role in biomolecular interactions due to its guanidinium side chain, which enables multivalent electrostatic and hydrogen bonding contacts. In this study, atomistic molecular dynamics simulations were conducted across a broad concentration range (26–605 mM) to investigate the thermodynamic and structural features of arginine self-assembly in aqueous solution. Key observables—including hydrogen bond count, radius of gyration, contact number, and isobaric heat capacity—were analyzed to characterize emergent behavior. A three-regime aggregation pattern (dilute, cooperative, and saturated) was identified and quantitatively modeled using the Hill equation, revealing a non-linear transition in clustering behavior. Spatial analyses were supplemented with trajectory-based clustering and radial distribution functions. The heat capacity peak observed near 360 mM was interpreted as a thermodynamic signature of hydration rearrangement. Trajectory analyses utilized both GROMACS tools and the MDAnalysis library. While force field limitations and single-replica sampling are acknowledged, the results offer mechanistic insight into how arginine concentration modulates molecular organization—informing the understanding of biomolecular condensates, protein–nucleic acid complexes, and the design of functional supramolecular systems. The findings are in strong agreement with experimental observations from small-angle X-ray scattering and differential scanning calorimetry. Overall, this work establishes a cohesive framework for understanding amino acid condensation and reveals arginine’s concentration-dependent behavior as a model for weak, reversible molecular association. 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

This review highlights how advances in silico techniques have shed new light on phenomena in confined supramolecular resorcinarene-based systems. Computational studies have provided detailed insights into capsule formation, their dynamic behavior, guest encapsulation and reaction mechanisms within these hosts, often revealing information that experimental methods cannot reach. The focus is placed on the self-assembly of resorcin[4]arenes, pyrogallol[4]arenes, velcrands, and octa acid systems. These computational studies complement experimental findings and, in many cases, offer new perspectives that are inaccessible using experimental techniques alone. Supramolecular architectures are growing in complexity the role of in silico approaches is becoming indispensable. They offer a way to design rationally and understand host–guest chemistry more deeply. 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

A polyoxometalate-based metal–organic complex with the ability to treat pollutants in water was obtained under hydrothermal conditions, namely [Ni(H₂L)(HL)₂](PMo₁₂O₄₀)·3H₃O·4H₂O (1) (H₂L = 4,4′-(1H,1′H-[2,2′-biimidazole]-1,1′-diyl)dibenzoicacid). Structural analysis reveals that the [Ni(H₂L)(HL)₂] units are interconnected into a 2D layer via hydrogen bonds between adjacent carboxyl groups and water molecules of crystallization. [PMo₁₂O₄₀]³⁻ anions are embedded within the larger pores of the layer and are connected to the adjacent layers through hydrogen bonds, ultimately expanding the structure into a 3D supramolecular architecture. The intermolecular interactions were studied via Hirshfeld surface (HS) analysis. Electrochemical performance tests reveal that 1 exhibits electrocatalytic activity toward the oxidation and reduction of diverse pollutants in water, including NO₂⁻, Cr(VI), BrO₃⁻, Fe(III), and ascorbic acid (AA). Additionally, it can also serve as an amperometric sensor for the detection of BrO₃⁻ and Cr(VI). Photocatalytic studies reveal that compound 1 functions as a bifunctional photocatalyst, which not only achieves efficient degradation of organic dyes but also demonstrates remarkable reduction efficiency for toxic Cr(VI). Compound 1 demonstrates significant potential for practical water remediation applications. Full article

Three diaryliodonium dicyanoargentates(I), [MesIAr][Ag(CN)₂] (Ar = Ph 1, Mes 2, 4-MeC₆H₄ 3; Mes = 2,4,6-Me₃C₆H₂), were prepared by anion metathesis. The X-ray structural analyses for these crystals revealed C–I^III∙∙∙N≡C halogen bonds (abbreviated as XB) between I atoms of diaryliodonium cations and N atoms of cyano groups, which provide different supramolecular organization. The noncovalent nature of these interactions was studied by density functional theory (DFT) calculations and topological analysis of the electron density distribution in the framework of the quantum theory of atoms in molecules (QTAIM) at the PBE-D3/jorge-DZP-DKH level of theory both in gas phase and crystal models. The philicities of partners in these contacts were confirmed by electron localization function (ELF) projections, electron density/electrostatic potential (ED/ESP) profiles, and Hirshfeld surfaces analysis. An analysis of the available crystallographic data from the literature allows us to find other examples of σ-hole interactions including the dicyanoargentate(I) anion, and the C–X∙∙∙N≡C (X = Br, I, Te) bonding were also confirmed theoretically. Full article

A chiral gelator (R)-H₆L with multiple carboxyl groups based on a 1,1′-bi-2,2′-naphthol (BINOL) skeleton was prepared, and it could form a supramolecular gel under the induction of water in DMSO/H₂O and DMF/H₂O (1/1, v/v). In the EtOH/H₂O system, the original partial gel transformed into a stable metal–organic gel (MOG), specifically with Cu²⁺ among 20 metal ions. It is proposed that Cu²⁺ coordinates with the carboxyl groups of (R)-H₆L to form a three-dimensional network structure. With the addition of a variety of α-hydroxy acids and amino acids, the Cu²⁺-MOG collapsed with merely 0.06 equivalents of L-tartaric acid (L-TA), while other acids required much larger amounts to achieve the same effect, realizing the visual chemoselective and enantioselective recognition of tartaric acid. Therefore, the chiral gelator (R)-H₆L achieved the tandem visual recognition of Cu²⁺ and chiral tartaric acid by sequence gel formation and collapse, offering valuable insights for visual sensing applications and serving as a promising model for future chiral sensor design. Full article

The crystal structures of naphthalene dicarboxamides, namely 1,4-naphthalene dicarboxamide (1,4-NDA), 2,6-naphthalene dicarboxamide (2,6-NDA), and 2,7-naphthalene dicarboxamide (2,7-NDA), are presented for the first time, along with an analysis of their supramolecular organization. The compounds, obtained in single-crystalline form via solvothermal crystallization from methanol, are stable in air to near 350 °C and have melting points above 300 °C. In their densely packed structures (ρ = 1.43–1.47 cm³g⁻¹) the combination of ${\mathrm{C}}_1^1$ (4) chains and ${\mathrm{R}}_2^2$(8) rings generates one-dimensional hydrogen-bonded ladders, with an additional ${\mathrm{R}}_4^2$(8) pattern. The amide groups and the naphthalene rings form dihedral angles between 22° and 40°. Neighboring H-bond ladders run parallel in 1,4-NDA and 2,6-NDA and are connected by means of the naphthalenedyil cores so that two-dimensional (2D) H-bonded sheets are obtained. Except for a weak intra-sheet π–π stacking in 1,4-NDA, there are no π–π stacking and C–H⋯π interactions. The ${\mathrm{R}}_2^2$(8) rings act as four-connected nodes, leading to the formation of two-dimensional H-bonded planar sheets with sql topology for the nearly linear dicarboxamides 1,4-NDA and 2,6-NDA and cds topology for the angular 2,7-NDA. Hirshfeld surface analysis and NCI plots provide additional insight into the H-bonding interactions. Full article

An example of an inorganic–organic hybrid compound {[Ag₄(SiW₁₂O₄₀)(HBTA)₈][Ag₄(SiW₁₂O₄₀)(HBTA)₈(H₂O)]}_n·(1) modified by the Keggin-type [SiW₁₂O₄₀]⁴⁻ polyoxoanion was synthesized hydrothermally, which was determined by single crystal X-ray diffraction. Two 1-dimensional (1D) chains are present in 1: chain a is connected by Ag···Ag interactions and chain b is connected by π···π stacking. Finally, they were extended into 2D and 3D supramolecular structures by hydrogen bonding. The photodegradation of methylene blue (MB) was investigated under visible light irradiation, and the degradation rate reached 99.4% within 200 min. In addition, 1 catalyzes the reduction of sodium nitrite and can be used as a potential electrocatalytic material. Full article