Supramolecular Hybrid Research Articles

A New Supramolecular Hybrid Based on Keggin Polyoxotungstates and Dinuclear Cl-Bridged Cu(II) Complex: Synthesis, Characterization, and Properties

A New Supramolecular Hybrid Based on Keggin Polyoxotungstates and Dinuclear Cl-Bridged Cu(II) Complex: Synthesis, Characterization, and Properties

Self-healing, injectable hydrogel based on dual dynamic covalent cross-linking against postoperative abdominal cavity adhesion

Clinically, increasing the peritoneal barrier is an effective adjunct to reducing postoperative peritoneal adhesion. This study presents a facile template for preparing a supramolecular hybrid hydrogel through dynamic covalent cross-linking between carboxymethyl chitosan (CMCS), 2-formylphenylboronic acid (2-FPBA), and quercetin (Que). The as-prepared complex CMCS/2-FPBA/Que (CFQ) hydrogel exhibited favorable antibacterial, anti-inflammatory, and antioxidant effects. A L929 cytotoxicity evaluation confirmed the favorable cytocompatibility of the CFQ hydrogel. The postoperative anti-adhesion ability of the CFQ hydrogel was further evaluated in rats with lateral wall defects and cecal abrasions. Compared with control groups, the tissue adhesion rate was significantly reduced by increasing the Que concentration in all the hydrogel-treated groups. Additionally, the sustained-release time of the C3F0.8Q0.08 hydrogel can exceed 14 days, which is highly desirable for clinical wound treatment. Statement of significancePostoperative adhesions are a very common postoperative complication that seriously affects the quality of life of patients. The currently commonly used methods for preventing adhesion mainly use degradable barrier materials for physical separation. In this study, we prepared a dual dynamic covalently cross-linked CFQ hydrogel, which is not only degradable and injectable, but also has multiple properties such as antibacterial, antioxidant and anti-inflammatory, which can effectively prevent postoperative adhesion and promote wound healing.

A supramolecular non centrosymmetric 2,6-diaminopyridinium perchlorate salt: Crystal structure and optoelectronic DFT study

The synthesis of a supramolecular hybrid perchlorate salt using the aromatic amine 2,6-diaminopyridine afforded an unexpected crystal structure with non centrosymmetric crystallographic symmetry. The synthesized material with formula (C5H8N3)ClO4 crystallize according to the monoclinic symmetry in the space group P21. The observed supramolecular crystal structure, consisting of only weak interactions in all the three dimensions, built from hydrogen bonds and through Anion…π+ interaction between (ClO4)- tetrahedrons of the mineral part and the aromatic rings of the organic molecules, is rarely observed for similar compounds. The electronic and optical properties are characterized at the theoretical level using DFT; these characterizations demonstrate a moderate direct band gap and a high optical anisotropy. Our results provide the essential information about structural, electronic and optical properties of (C5H8N3)ClO4, which are useful for guiding the future studies.

Process for the catalytic conversion of micro-carbon residue content of heavy hydrocarbon feedstocks and a low surface area catalyst composition for use therein

The synthesis of a supramolecular hybrid perchlorate salt using the aromatic amine 2,6-diaminopyridine afforded an unexpected crystal structure with non centrosymmetric crystallographic symmetry. The synthesized material with formula (C5H8N3)ClO4 crystallize according to the monoclinic symmetry in the space group P21. The observed supramolecular crystal structure, consisting of only weak interactions in all the three dimensions, built from hydrogen bonds and through Anion…π+ interaction between (ClO4)- tetrahedrons of the mineral part and the aromatic rings of the organic molecules, is rarely observed for similar compounds. The electronic and optical properties are characterized at the theoretical level using DFT; these characterizations demonstrate a moderate direct band gap and a high optical anisotropy. Our results provide the essential information about structural, electronic and optical properties of (C5H8N3)ClO4, which are useful for guiding the future studies.

Graphene Quantum Dots and Phthalocyanines Turn-OFF-ON Photoluminescence Nanosensor for ds-DNA.

Supramolecular hybrids of graphene quantum dots (GQDs) and phthalocyanine (Pc) dyes were studied as turn-OFF-ON photoluminescence nanosensors for detection of ds-DNA. Pcs with four (Pc4) and eight (Pc8) positive charges were selected to interact with negatively charged GQDs. The photoluminescence of the GQDs was quenched upon interaction with the Pcs, due to the formation of non-emissive complexes. In the presence of ds-DNA, the Pcs interacted preferentially with the negatively charged ds-DNA, lifting the quenching effect over the photoluminescence of the GQDs and restoring their emission intensity. The best performance as a sensor of ds-DNA was registered for the GQD-Pc8, with a limit of detection (LOD) in the picomolar range. The LOD for GQD-Pc8 was more than one order of magnitude lower and its sensitivity was about a factor of three higher than that of the analogue GQD-Pc4 nanosensor. The sensitivity and selectivity of this simple GQD-Pc8 nanosensor is comparable to those of the more sophisticated carbon-based nanosensors for DNA reported previously.

Supramolecular Hybrids from Cyanometallate Complexes and Diblock Copolypeptide Amphiphiles in Water.

The self-assembly of discrete cyanometallates has attracted significant interest due to the potential of these materials to undergo soft metallophilic interactions as well as their optical properties. Diblock copolypeptide amphiphiles have also been investigated concerning their capacity for self-assembly into morphologies such as nanostructures. The present work combined these two concepts by examining supramolecular hybrids comprising cyanometallates with diblock copolypeptide amphiphiles in aqueous solutions. Discrete cyanometallates such as [Au(CN)2]−, [Ag(CN)2]−, and [Pt(CN)4]2− dispersed at the molecular level in water cannot interact with each other at low concentrations. However, the results of this work demonstrate that the addition of diblock copolypeptide amphiphiles such as poly-(L-lysine)-block-(L-cysteine) (Lysm-b-Cysn) to solutions of these complexes induces the supramolecular assembly of the discrete cyanometallates, resulting in photoluminescence originating from multinuclear complexes with metal-metal interactions. Electron microscopy images confirmed the formation of nanostructures of several hundred nanometers in size that grew to form advanced nanoarchitectures, including those resembling the original nanostructures. This concept of combining diblock copolypeptide amphiphiles with discrete cyanometallates allows the design of flexible and functional supramolecular hybrid systems in water.

Self-healing epoxidized natural rubber with ionic/coordination crosslinks

Self-healing polymers with strong mechanical robustness and superior self-healing ability are of interest in coatings, electronics, structural components, etc. However, it is difficult to realize these properties simultaneously, owing to the mutually exclusive requirements: the mechanical robustness of materials needs strong bonds to form robust network, but a strong bond leads to weak self-healing capability. In this work, we report the rational design of epoxidized natural rubber (ENR) incorporating with ionic and coordination supramolecular hybrid bond network, in which these two kinds of bonds possess identical cross-linking point yet contrasting bond strength. The optical microscope pictures and the temperature-dependent infrared spectra analysis show that ionic bonds rapidly shorten the spatial distance of the ENR chains located on both sides of the ionic bond to assemble into a stable network with lower energy state owing to its short temporal timescale for reconstruction, and simultaneously promote the reconstruction of coordination bond as a result of their sharing the same cross-linking point. The cooperative collaboration of these two bonds lead to a tensile stress of 1.33 MPa, a strain of 600%, and a healing efficiency of 92% after healing for 3 h at ambient temperature. This novel self-healing material is promising for various applications, especially when the component is difficult to disassemble or with limited enviroment conditions.

Nitric Oxide-Releasing Supramolecular Cellulose Nanocrystal/Silsesquioxane Foams.

Cellulose nanocrystals (CNC)-based foams are promising tissue engineering materials that may facilitate implant-tissue integration and allow localized and controlled drug delivery. Herein, hybrid CNC-based foams, which are ultralightweight (30-100mg cm-3 ), highly porous (>95%), ominiphilic and superabsorbent (1500-3000 wt% of water and/or toluene uptake) are obtained by the in situ condensation of poly(ethylene glycol) ditriethoxysilyl (TES-PEG-TES) into a 3D network, where silsesquioxane nanoparticles (SS-NP) are the crosslinking nodes, and CNC are entrapped forming ionic interactions, in a supramolecular structure. In a new approach, using 3-mercaptopropyltrimethoxysilane, sulfhydryl groups are inserted on the SS-NP periphery and S-nitrosated to enable the functionalization of SS-NP with S-nitrosothiol groups, which can nitric oxide (NO), in a process triggered by the hydration of the foams and modulated by their supramolecular structure. CNC-SS-PEG foams exhibit elevated thermal and structural stability, compressive strength compatible with various soft human tissues, and NO release rates (1-18pmol mg-1 min-1 ) within the range of the beneficial NO actions. Thus, the CNC-SS-PEG foams herein described represent a new platform of supramolecular hybrid materials for localized delivery of NO, with potential uses in tissue engineering and other biomedical applications.

Pillar[5]arene based glyco-targeting nitric oxide nanogenerator for hyperthermia-induced triple-mode cancer therapy

Nitric oxide (NO)-mediated gas therapy (GT) and alkyl radical (R•) therapy (ART) are emerging cancer therapy modes, and multi-mode therapy has been recognized as an attractive strategy for enhancing anti-cancer efficacy. In this work, a thermal-responsive R• initiator 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIBI)-loaded glycol-targeting NO nanogenerator was constructed by first the covalent conjugation of thermal-responsive NO donor of S-nitrosothiols (RSNO) on the surface of mesoporous silica-coated gold nanorods (AuNRs@MSN), then the coating of a supramolecular complex of amino pillar[5]arene (NP5) and galactose derivative (G), and finally the loading of AIBI. The glycol-targeting NO nanogenerator demonstrated specific targeting ability to HepG2 cells owing to the recognition between galactose residues and asialoglycoprotein receptors (ASGPR). Specially, upon 808 nm near-infrared (NIR) irradiation, the AIBI-loaded NO nanogenerator generated hyperthermia to achieve photothermal therapy (PTT), and further GT and ART resulted from the thermal responsiveness of RSNO and AIBI, respectively. In vitro experiments revealed that the AIBI-loaded glyco-targeting NO nanogenerator had good biocompatibility and exhibited effective inhibition to the proliferation of HepG2 cells. This work provides a novel way to supramolecular hybrid drug delivery systems for triple-mode targeting therapy of PTT/GT/ART.

A novel supramolecular self-assembling hybrid system for visible-light-driven overall water splitting

A hybrid supramolecular system containing redox compartments has been successfully developed for visible-light-driven overall water splitting in the ambient environment.

Injectable Supramolecular Hybrid Hydrogel Delivers Interleukin-1β-Engineered Exosomes to Target Neuroinflammation in Cerebral Ischemia–Reperfusion Injury

Injectable Supramolecular Hybrid Hydrogel Delivers Interleukin-1β-Engineered Exosomes to Target Neuroinflammation in Cerebral Ischemia–Reperfusion Injury

Dynamic hybridization of fluorescence polymers upon complexation of glucan

Hybridization of natural/biomacromolecules with synthetic polymers has become a convenient, powerful alternative to the conventional approaches for creating supramolecular hybrid architectures, assemblies, and scaffolds. The hybridization behavior of fluorescence polymers (TPE-PE and Dns-PS) upon the complexation of curdlan (Cur) was fully investigated in an aqueous solution by means of fluorescence, excitation, and circular dichroism spectroscopies and fluorescence lifetime, quantum yield, anisotropy, and zeta potential measurements. Upon mixing with Cur to the aqueous solution containing TPE-PE or Dns-PS, a polyionic hetero-triplex was formed as prepared, the complexation stoichiometry of which was determined through fluorescence/excitation spectral titration experiments (molar ratio plots), which was greatly accelerated by adding a salt and then disassembled to a loose hetero-duplex in a highly basic solution. A validity of the dynamic hybridization mechanism was strongly proved herein, which may further contribute to the rational design of synthetic polymers as well as the strategic choice of natural/biomacromolecules.

Study the Effects of Supramolecular Interaction on Diffusion Kinetics in Hybrid Hydrogels of Zwitterionic Polymers and CNTs

AbstractHybrid hydrogel systems of functionalized multi‐walled carbon nanotubes and zwitterionic sulfobetaine copolymer of thermo‐responsible poly(N‐isopropylacrylamide) (PNIPAM) are synthesized and testified against different existing diffusion kinetic models in neutral, acidic, and basic environments. Evaluating these hybrid hydrogels’ swelling patterns at different pH indicates that changing pH can tailor the diffusion mechanism without affecting its diffusion kinetics. Interestingly, it is also revealed that diffusion kinetics and diffusion mechanisms are two distinct phenomena and can be viewed separately for supramolecular hybrid hydrogel systems. Elovich kinetic model best describes the swelling kinetics of only PNIPAM hydrogel. Diffusion kinetics of hybrid hydrogel of PNIPAM and CNTs or PNIPAM, zwitterion, and CNTs follow pseudo‐first‐order, while pseudo‐second‐order‐kinetics best describe hydrogels with only zwitterions. Evaluation of diffusion mechanism at different pH reveals that hydrogels with only zwitterions follow anomalous non‐Fickian diffusion, whereas only CNTs follow normal Fickian diffusion irrespective of pH; combining both systems leads to a dual‐stage diffusion mechanism at pH 2, which in turn reduces as the pH increases. These observations suggest that synergistic effects of supramolecular interactions can provide a novel property profile to hybrid hydrogels, requiring attention while designing such a system where diffusion is a decisive parameter.

Structure Evolution and Thermal Decomposition of Supramolecular and Lamellar Hybrid Sulfates Templated by 4-Aminopyridinium

The aromatic diamine 4-aminopyridine was used for the synthesis of a series of supramolecular metal–organic sulfate salts. The obtained compounds with the formula (C5H7N2)2[MII(H2O)6](SO4)2 (MII = Fe, Co, Ni, Cu and Zn) and (C5H7N2)2[Mn(H2O)4(SO4)2] crystallize with a triclinic symmetry (S.G. P \(\overline{1 }\)). These complexes possess a hybrid structure type with an interlayer distance that varies from 10 to 12 Å depending on the metal. The supramolecular aspect of the crystal structure is manifested through mineral layers, which are built up uniquely from hydrogen bonds. The interlayer space is filled with aromatic diamines that form chains through π⋯π interactions. The thermal study in-situ of all metal compounds revealed important stability with the formation of crystalline phases during heating. The dehydration proceeds differently according to the metal incorporated into the structure.

Light-Programmable Logic-in-Memory in 2D Semiconductors Enabled by Supramolecular Functionalization: Photoresponsive Collective Effect of Aligned Molecular Dipoles.

Nowadays, the unrelenting growth of the digital universe calls for radically novel strategies for data processing and storage. An extremely promising and powerful approach relies on the development of logic-in-memory (LiM) devices through the use of floating gate and ferroelectric technologies to write and erase data in a memory operating as a logic gate driven by electrical bias. In this work, we report an alternative approach to realize the logic-in-memory based on two-dimensional (2D) transition metal dichalcogenides (TMDs) where multiple memorized logic output states have been established via the interface with responsive molecular dipoles arranged in supramolecular arrays. The collective dynamic molecular dipole changes of the axial ligand coordinated onto self-assembled metal phthalocyanine nanostructures on the surface of 2D TMD enables large reversible modulation of the Fermi level of both n-type molybdenum disulfide (MoS2) and p-type tungsten diselenide (WSe2) field-effect transistors (FETs), to achieve multiple memory states by programming and erasing with ultraviolet (UV) and with visible light, respectively. As a result, logic-in-memory devices were built up with our supramolecular layer/2D TMD architecture where the output logic is encoded by the motion of the molecular dipoles. Our strategy relying on the dynamic control of the 2D electronics by harnessing the functions of molecular-dipole-induced memory in a supramolecular hybrid layer represents a versatile way to integrate the functional programmability of molecular science into the next generation nanoelectronics.

Light‐Harvesting Supramolecular Phosphors: Highly Efficient Room Temperature Phosphorescence in Solution and Hydrogels

AbstractSolution phase room‐temperature phosphorescence (RTP) from organic phosphors is seldom realized. Herein we report one of the highest quantum yield solution state RTP (ca. 41.8 %) in water, from a structurally simple phthalimide phosphor, by employing an organic–inorganic supramolecular scaffolding strategy. We further use these supramolecular hybrid phosphors as a light‐harvesting scaffold to achieve delayed fluorescence from orthogonally anchored Sulforhodamine acceptor dyes via an efficient triplet to singlet Förster resonance energy transfer (TS‐FRET), which is rarely achieved in solution. Electrostatic cross‐linking of the inorganic scaffold at higher concentrations further facilitates the formation of self‐standing hydrogels with efficient RTP and energy‐transfer mediated long‐lived fluorescence.

Supramolecular Assembly of Hybrid Pt(II) Porphyrin/Tomatine Analogues with Different Nanostructures and Cytotoxic Activities.

A simple strategy for synthesizing supramolecular hybrids was developed for the preparation of bioavailable nanohybrid photosensitizers by assembling visible-light-sensitive Pt(II) meso-tetrakis(4-carboxyphenyl)porphyrinporphyrin (PtTCPP)/tomatine analogues. The hybrids were self-assembled into nanofibrous or nanosheet structures approximately 3–5 nm thick and several micrometers wide. α-Tomatine generated a unique fibrous vesicle nanostructure based on intermolecular interactions, while dehydrotomatine generated nanosheet structures. Nanoassembly of these fibrous vesicles and sheets directly affected the properties of the light-responsive photosensitizer for tumor photodynamic therapy (PDT), depending on the nanostructure of the hybrid PtTCPP/tomatine analogues. The cytotoxicity of PtTCPP to cancer cells under photoirradiation was significantly enhanced by a tomatine assembly with a fibrous vesicle nanostructure, attributable to increased incorporation of the drug into cells.

Electrospun Supramolecular Hybrid Microfibers from Conjugated Polymers: Color Transformation and Conductivity Evolution

A type of novel electrospun supramolecular hybrid microfibers comprising poly(9-(4-(octyloxy)-phenyl)-2,7-fluoren-9-ol) (PPFOH) and poly(N-vinylcarbazole) (PVK) are successfully prepared for intriguing multi-color emission properties. The supramolecular tunable PPFOH aggregation in PVK matrix endows the complex with a smart energy transfer behavior to obtain the multi-color emissions. In stark contrast to PVK fibers, the emission color of PPFOH/PVK fibers with an efficient dispersion of PPFOH fluorophores at a proper dope ratio can be tuned in a wide spectrum of blue (0.1%), sky blue (0.5%), nearly white (1%), cyan (2%), green (5%) and yellow (10%). Besides, conductive behaviors of the microfiber were demonstrated in accompany with the increment of the doping ratio of PPFOH to PVK. Successful fabrication of polymer light-emitting diode (PLED) based on the blended electrospun fiber provided a further evidence of its excellent electrical property for potential applications in optoelectronic devices.

The Testing Method of Graphene Oxide (GO) and NAA Ramification

Organic/inorganic supramolecular system has been obtained by graphene oxide grafting with a-cyclodextrins (a-CDs) and NAA ramification. Tourer transform infrared spectra (FTIR), thermogravimetric analyse (TGA), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and X-ray photoelectron spectroscopy (XPS) were employed to identify the characters and morphology of the supramolecular structure. The features might make our supramolecular hybrid hydrogel a pretty candidate in a drug delivery system.

Silver nanoparticles decorated phthalocyanine doped polyaniline for the simultaneous electrochemical detection of hydroquinone and catechol

Abstract In this proposed study, the new electrocatalyst was synthesized by incorporating the supramolecular electrocatalyst tetra amino cobalt phthalocyanine (TACoPc) into the conducting polyaniline (PANI) and which was subsequently used to decorate silver nanoparticles (AgNPs) using Ag+ solution on the surface of TACoPc/PANI composite to form a supramolecular hybrid system. The decoration of AgNPs on the surface of TACoPc/PANI was carried out in an aqueous media at room temperature and which was confirmed by various spectroscopic techniques. The synthesized catalyst AgNPs decorated TACoPc doped PANI (TACoPc/PANI/AgNPs) modified the glassy carbon electrode (GCE) used to construct the electrochemical sensor for simultaneous detection of hydroquinone (HQ) and catechol (CC). The modified electrode showed the two distinct peaks for HQ and CC in CV analysis with a considerable potential difference of 0.080 V vs SHE. The presence of central cobalt metal in TACoPc macromolecular electrocatalyst mediates the oxidation of HQ and CC, which was successively enhanced by the incorporation of conducting PANI and AgNPs. The sensor exhibited excellent electrocatalytic activity with good stability, selectivity, reproducibility, and a very low limit of detection in the electrochemical sensing of HQ and CC in a 0.1 M H2SO4 electrolyte solution.