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Photoresponsive Halogen-Bonded Liquid Crystals: The Role of Aromatic Fluorine Substitution
摘要： A new strategy for controlling the liquid crystalline and photophysical properties of supramolecular mesogens assembled via halogen bonding is reported. Changing the degree of fluorination at the halogen-bond donor of the supramolecular liquid crystal allows for the fine-tuning of the halogen bond strength and thereby provides control over the temperature range of the mesophase. At least three fluorine atoms have to be present to ensure efficient polarization of the halogen-bond donor and the formation of a mesophase. In addition, it was found that stilbazole acceptors are superior to their azopyridine counterparts in promoting stable liquid crystalline phases. The halogen-bond-driven supramolecular liquid crystals between fluorinated azobenzenes and stilbazole/azopyridine acceptors show a rich variety of photoinduced processes driven by azobenzene photoisomerization, dictated not only by the photochemical properties of the molecular components but also by the difference between the operation temperature and the clearing point.
关键词： photoresponsive materials,fluorination,supramolecular chemistry,azobenzenes,halogen bonding,liquid crystals
更新于2025-09-23 15:23:52
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Heterobimetallic (Fe <sup>II</sup> /Pt <sup>II</sup> )-Based Supramolecular Coordination Complexes Using 1,1′-Ferrocene Dicarboxylate: Self-Assembly and Interaction with Carbon Dots
摘要： The synthesis and characterization of a new pyrazine-based ditopic organoplatinum(II) complex having a bite angle of 180° is reported. The facile and efficient syntheses are described of three discrete neutral Fe(II)/Pt(II) heterobimetallic SCCs with Pt(II) acceptor clips of different binding angles, 0, 120, and 180°. These new SCCs were characterized by multinuclear NMR and mass spectrometry. Electrochemical response of these ferrocene containing self-assembled ensembles was studied using cyclic voltammetry. The diplatinum acceptor organometallic clips significantly quench the fluorescence of highly emitting carbon quantum dots (CD), while the self-assembled macrocycles tend to nullify the quenching effect of the organometallic clips. Interestingly, the inefficient quenching of CD fluorescence by these SCCs was found to be directly related to the angular disposition of the binding sites in the Pt(II) based organometallic clips.
关键词： carbon dots,heterobimetallic,electrochemical response,self-assembly,supramolecular coordination complexes,fluorescence quenching,ferrocene
更新于2025-09-23 15:23:52
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Chiral Recognition of L- and D- Amino Acid by Porphyrin Supramolecular Aggregates
摘要： We report of the interactions between four amino acids lysine (Lys), arginine (Arg), histidine (His), and phenylalanine (Phe) with the J-aggregates of the protonated 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphyrin H4TPPS. Several aspects of these self-assembled systems have been analyzed: (i) the chiral transfer process; (ii) the hierarchical effects leading to the aggregates formation; and, (iii) the influence of the amino acid concentrations on both transferring and storing chiral information. We have demonstrated that the efficient control on the J-aggregates chirality is obtained when all amino acids are tested and that the chirality transfer process is under hierarchical control. Finally, the chiral porphyrin aggregates obtained exhibit strong chiral inertia.
关键词： porphyrin,self-assembly,amino acid,circular dichroism,supramolecular chirality
更新于2025-09-23 15:22:29
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Smart Supramolecular “Trojan Horse”-Inspired Nanogels for Realizing Light-Triggered Nuclear Drug Influx in Drug-Resistant Cancer Cells
摘要： Efficient nuclear delivery of anticancer drugs evading drug efflux transporters (DETs) on the plasma and nuclear membranes of multidrug-resistant cancer cells is highly challenging. Here, smart nanogels are designed via a one-step self-assembly of three functional components including a biocompatible copolymer, a fluorescent organosilica nanodot, and a photodegradable near-infrared (NIR) dye indocyanine green (ICG). The rationally designed nanogels have high drug encapsulation efficiency (≈99%) for anticancer drug doxorubicin (Dox), self-traceability for bioimaging, proper size for passive tumor targeting, prolonged blood circulation time for enhanced drug accumulation in tumor, and photocontrolled disassemblability. Moreover, the Dox-loaded nanogels can effectively kill multidrug-resistant cells via two steps: 1) They behave like a “Trojan horse” to escape from the DETs on the plasma membrane for efficiently transporting the anticancer “soldier” (Dox) into the cytoplasm and preventing the drugs from being excreted from the cells; 2) Upon NIR light irradiation, the photodegradation of ICG leads to the disassembly of the nanogels to release massive Dox molecules, which can evade the DETs on the nuclear membrane to exert their intranuclear efficacy in multidrug-resistant cells. Combined with their excellent biocompatibility, the nanogels may provide an alternative solution for overcoming cancer multidrug resistance.
关键词： nuclear delivery,photocontrollable drug release,cancer theranostics,silicon-based nanomaterials,supramolecular assembly
更新于2025-09-23 15:22:29
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Squaraine dyes: interaction with bovine serum albumin to investigate supramolecular adducts with aggregation-induced emission (AIE) properties
摘要： Bovine Serum Albumin (BSA)–squaraine supramolecular adducts with aggregation-induced emission (AIE) properties were prepared and characterized by spectroscopic methods. While squaraine dyes showed very low fluorescence quantum yield in water, a great enhancement in the fluorescence of the aggregated BSA adducts was achieved due to the abnormal aggregation-induced emission properties of squaraines. The adducts formation was studied from a kinetic point of view showing unexpected structure-properties relationships.
关键词： squaraines,supramolecular adducts,Bovine Serum Albumin (BSA),kinetics,Aggregation-induced emission (AIE)
更新于2025-09-23 15:22:29
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Light-powered, artificial molecular pumps: a minimalistic approach
摘要： The realization of artificial molecular motors capable of converting energy into mechanical work is a fascinating challenge of nanotechnology and requires reactive systems that can operate away from chemical equilibrium. This article describes the design and construction of a simple, supramolecular ensemble in which light irradiation causes the directional transit of a macrocycle along a nonsymmetric molecular axle, thus forming the basis for the development of artificial molecular pumps.
关键词： molecular machine,azobenzene,rotaxane,supramolecular chemistry,photochemistry
更新于2025-09-23 15:22:29
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Photoswitchable Host-Guest Systems Incorporating Hemithioindigo and Spiropyran Units
摘要： We cover selected examples of the incorporation of hemithioindigo and spiropyran units in one of the binding partners of synthetic host-guest systems. In some of the simplest systems, isomerization of the switch simply modulates the thermodynamic stability of the two isomeric host-guest complexes. In the presence of more than two binding partners, the isomerization of the molecular switch alters the composition of the multicomponent host-guest system producing a shuttling process of one of the components between different hosts. In others, the isomerization process controls the uptake and release of some of the components from/to the bulk solution. We show that the understanding of the isomerization mechanisms of the molecular switches and the effects produced by the external stimuli are essential for the design of complex and responsive supramolecular host-guest systems. The physicochemical properties of the hemithioindigo and spiropyran molecular photoswitches are complementary, providing different avenues to their applications in solution and material science.
关键词： Spiropyrans,Hemithioindigos,Host-Guest Systems,Supramolecular Assemblies,Photoswitches
更新于2025-09-23 15:22:29
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Synthesis, Crystal Structure, and Properties of a Zn(II) Coordination Polymer Based on a Difunctional Ligand Containing Triazolyl and Carboxyl Groups
摘要： A new compound, namely, [Zn(L)2]n (1) was obtained by the reaction of 2-methyl-4-(4H-1,2,4-triazol-4-yl) benzoic acid (HL) with ZnSO4·7H2O, and the compound was characterized by single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, powder X-ray diffraction (PXRD), and thermogravimetric analysis. The linear HL ligands were deprotonated to be L? anions and act as two-connectors to link Zn2+ to form a two-dimensional (2D) lay structure with (4, 4) topology. The large vacancy of 2D framework allows another layer structure to interpenetrate, resulting in the formation of 2D + 2D → 2D parallel interpenetration in 1. The weak interactions, such as hydrogen bonding and π–π stacking interactions, connect the adjacent 2D layers into a three-dimensional (3D) coordination polymer. The solid-state UV-visible spectroscopy and luminescent property have also been studied.
关键词： supramolecular polymer,spectral property,crystal structure
更新于2025-09-23 15:22:29
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Self-Assembly of Amphiphilic Schiff Base and Selectively Turn on Circularly Polarized Luminescence by Al3+
摘要： We designed glutamide-derived amphiphilic Schiff bases containing three different aldehyde moieties for the fabrication of circularly polarized luminescence (CPL) emitting materials. Upon self-assembly in acetonitrile, Schiff bases featuring 4-(dimethylamino)-2-hydroxylbenzaldehyde and 1-hydroxy-2-naphthaldehyde groups form supramolecular gels with twist and fiber structures, respectively, while Schiff bases featuring 2-hydroxy-1-naphthaldehyde groups forms precipitation with flakes structures. Although emission and circular dichroism (CD) signals can be detected from the supramolecular gels formed by amphiphilic Schiff bases, none of them exhibits circularly polarized luminescence (CPL). While Mg2+, Zn2+ and Al3+ can both significantly enhance the fluorescence of the Schiff bases, interestingly, only Al3+ ion is able to turn on the CPL emission. This study on the one hand provides a simple method to the fabrication of CPL emitting supramolecular materials, and on the other hand offers a novel way to the sensing of aluminum ion with supramolecular materials.
关键词： Self-assembly,Schiff bases,Circularly polarized luminescence,Al3+,Supramolecular gels
更新于2025-09-23 15:21:21
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Control on Dimensions and Supramolecular Chirality of Self-Assemblies through Light and Metal Ions
摘要： Precise control over helical chirality and dimensions of molecular self-assemblies, a remaining challenge for both chemists and materials scientists, is the key to manipulate the property and performance of supramolecular materials. Herein, we report that a cholesterol-azopyridine conjugate could self-assemble into organogels with photo-controllable dimensional transition from 2D microbelts to 1D nanotubes and finally to 0D nanoparticles. The E/Z-Photoisomerization of the 4-azopyridine unit is the major driving force for the dimensional transformation. Furthermore, the self-assembled structures were observed to exhibit metal ion-mediated helicity inversion through the metal coordination. These observations were collectively confirmed by several techniques including scanning electron microscopy, atomic force microscope, circular dichroism, and X-ray crystallography. The rational design of building blocks for the construction of dimension and chirality controllable self-assembly systems may lead to versatile applications in smart display, advanced optoelectronic device, and supramolecular asymmetric catalysis.
关键词： photoisomerization,dimensional transition,supramolecular chirality,metal coordination,self-assembly
更新于2025-09-23 15:21:21