Linear Supramolecular Polymers Research Articles

Cross-linked supramolecular polymers synthesized by photo-initiated thiol-ene click reaction of supramonomers

Supramonomers refer to monomers fabricated via noncovalent interactions and can be polymerized through conventional covalent methods. In this article, we realized the fabrication of cross-linked supramolecular polymers through photo-initiated thiol-ene click reaction of quadruple hydrogen bonded supramonomers. It is found that the cross-linked supramolecular polymer has a higher critical polymerization concentration than the linear supramolecular polymer, because the orientation of the trifunctional monomer leads to cyclize at low concentrations. It is anticipated that this research can enrich the methodology of fabricating cross-linked supramolecular polymers and provide a new phenomenon to understand the self-assembling behavior of cross-linked supramolecular polymers.

Supramolecular Polymer of Near-Infrared Luminescent Porphyrin Glass

A comprehensive study of supramolecular polymerization of ditopic zinc (2-pyridylethynyl)porphyrin dimer 1 in toluene and thin films was performed. A glass-forming porphyrin bearing 3,4,5-tri((S)-3,7-dimethyloctyloxy)phenyl groups, named “porphyrin glass”, was introduced with the 2-pyridylethynyl group as a supramolecular organizing unit; two zinc (2-pyridylethynyl)porphyrins were held together by self-complementary pyridyl-to-zinc coordination bonds to form a slipped-cofacial stack. Then, ditopic zinc (2-pyridylethynyl)porphyrin could be extended to a linear supramolecular polymer. The small binding constant limited the degree of supramolecular polymerization of 1 in toluene solution. In spin-cast film, on the other hand, 1 adopted a form of supramolecular polymer of porphyrin glass, which was effective enough to display a large bathochromic shift of the absorption bands exceeding the narrowest limit of the optical band gap extrapolated from the electronic structures in solution. The supramolecularly pol...

Modulating the properties of quadruple hydrogen bonded supramolecular polymers by photo-cross-linking between the coumarin moieties

Novel linear supramolecular polymers were successfully constructed by self-assemblies of coumarin-bridged bifunctional UPy derivative. Benefitting from the photodimerization ability of the coumarin moieties, the linear supramolecular polymers could form the large three-dimensional polymer networks upon UV light irradiation via photo-cross-linking, which provides a viable and alternative procedure to modulate the properties of supramolecular polymers.

Construction of stimuli-responsive supramolecular gel via bispillar[5]arene-based multiple interactions

A linear supramolecular polymer has been constructed from host–guest recognition. Furthermore, the linear supramolecular polymer could self-assemble to form a supramolecular gel at high concentration, which exhibited external stimuli-responsiveness.

In situ supramolecular polymerization promoted by the marriage of dynamic covalent bonding and pillar[5]arene-based host-guest interaction.

In situ fabrication of a temperature and pH dual-responsive linear supramolecular polymer through the marriage of dynamic covalent bonding and pillar[5]arene-based host-guest interaction was investigated.

Neutral linear supramolecular polymers constructed by three different interactions

Neutral linear supramolecular polymers were constructed by the combination of quadruple hydrogen bonding, pillar[5]arene-based molecular recognition and π–π donor–acceptor interactions.

Interfacial Au nanoparticle decoration of a disulfide modified G-wire.

The guanine-rich oligonucleotide (GRO), dGGGGTTGGGG (G4T2G4), has the capacity to form a linear supramolecular polymer known as a G-wire. Individual nucleotides of the component GROs can be functionally modified to serve as site-specific attachment points in the G-wire while not interfering with its self-assembling properties. An amine linker modification to an internal thymine base of the GRO, denoted G4TT*G4, serves as a chemically versatile attachment site. In this work, addition of an alkyl disulfide to G4TT*G4 produces the GRO G4TTdG4 enabling binding to gold nanoparticles via place exchange chemistry. G-wires assembled by combining G4T2G4 and G4TTdG4 were stably maintained in an aqueous environment. Disulfide modified G-wires (DS_G-wire) were then covered with dodecanethiol capped gold nanoparticles in an organic solvent via an interfacial place exchange reaction. Tapping Mode AFM and TEM were used to image G-wires decorated with gold nanoparticles. The specificity of the interfacial place exchange reaction was measured using a fluorometric dye displacement from the gold nanoparticles. The results show that a two component DS_G-wire with an amphipathic tether readily self-assemble as shown by PAGE and TM-AFM. The amphipathic disulfide moiety of DS_G-wires facilitates place exchange chemistry with alkylthiol protected Au nanoparticles across an aqueous-organic interface. Interfacial place exchange is an effective strategy for decorating DS_G-wires with Au nanoparticles. The use of modified G-wire self-assembly combined with a high degree of nanoparticle binding specificity presents another strategy for the use of G-wires as a rigid one-dimensional molecular scaffold with potential applications in nanoscale device construction. This article is part of a Special Issue entitled "G-quadruplex" Guest Editor: Dr. Concetta Giancola and Dr. Daniela Montesarchio.

ChemInform Abstract: Supramolecular Polymers and Networks Driven by Cucurbit[8]uril‐guest Pair Encapsulation in Water

AbstractReview: 95 refs.

Metal Coordination Stoichiometry Controlled Formation of Linear and Hyperbranched Supramolecular Polymers.

Controlling the topologies of polymers is a hot topic in polymer chemistry because the physical and/or chemical properties of polymers are determined (at least partially) by their topologies. This study exploits the host-guest interactions between dibenzo-24-crown-8 and secondary ammonium salts and metal coordination interactions between 2,6-bis(benzimidazolyl)-pyridine units with metal ions (Zn(II) and/or Eu(III) ) as orthogonal non-covalent interactions to prepare supramolecular polymers. By changing the ratios of the metal ion additives (Zn(NO3 )2 and Eu(NO3 )3 ) linkers to join the host-guest dimeric complex, the linear supramolecular polymers (100 mol% Zn(NO3 )2 per ligand) and hyperbranched supramolecular polymers (97 mol% Zn(NO3 )2 and 3 mol% Eu(NO3 )3 per ligand) are separately and successfully constructed. This approach not only expands topological control over polymeric systems, but also paves the way for the functionalization of smart and adaptive materials.

Photo and redox dual-stimuli-directed reversible disassembly and reassembly of linear supramolecular polymer formed by orthogonal host-guest molecular recognition

Bottom-up fabrication of functional supramolecular systems from discrete molecular building blocks is a flourishing endeavor in contemporary science and nanotechnology. Here we present the synthesis and reversible disassembly and reassembly of adual-stimuli responsive linear supramolecular polymer constructed by host-guest molecular recognition. The formation of the supramolecular polymer is driven by exceptional selective complexation property of azobenzene with β-cyclodextrin and 4,4´-bipyridinium with sulfonatocalix[4]arene, which ensures the polymer’s controlled and orthogonal responsiveness to light irradiation and redox process. The supramolecular polymerization was confirmed by 1H NMR spectroscopy, dynamic light scattering (DLS) measurement, atomic force microscopy (AFM), and transmission electron microscopy (TEM), and its reversible photo and redox dual-responsive disassembly and reassembly behavior was as certained by UV–vis absorption spectra, cyclic voltammetry (CV), and TEM. This is the first example of a supramolecular polymer capable of reversible disassembly and reassembly driven by light and redox process, involving solely non-covalent orthogonal molecular recognition, which can be recognized by naked eyes.

Construction of a neutral linear supramolecular polymer via orthogonal donor–acceptor interactions and pillar[5]arene-based molecular recognition

A neutral linear supramolecular polymer was efficiently constructed by donor–acceptor interactions and pillar[5]arene-based molecular recognition through hierarchical orthogonal strategies.

Light driven bent linear supramolecular polymer

Linear supramolecular polymer with photo-responsive morphology was constructed by host-guest molecular recognition between bis-p-sulfonatocalix[4]arenes and monomer containing axially 1,1′-binaphthyl and photoresponsive azobenzene moieties in water. The successful supramolecular polymerization by non-covalent host-guest molecular recognition was confirmed. Scanning electron microscopy, cryogenic transmission electron microscopy and atomic force microscopy measurements were used to investigate its light driven behavior and line morphology change from straight to bent. Its noteworthy light driven morphology change from straight to bent make it possible to envision its' usage as molecular machine based display material in the same way as bent-core liquid crystal material used in technology.

K+ responsive supramolecular polymer constructed by dibenzo-30-crown-10/paraquat-based molecular recognition

A supramolecular polymer constructed by dibenzo-30-crown-10/paraquat-based molecular recognition is reported. Owing to the responsiveness and reversibility of the dibenzo-30-crown-10/paraquat host−guest interactions, the reversible transition between the linear supramolecular polymer and monomers is achieved by adding K+ and DB18C6.

A novel supramolecular polymer gel constructed by crosslinking pillar[5]arene-based supramolecular polymers through metal–ligand interactions

A novel heteroditopic A-B monomer was synthesized and used to construct linear supramolecular polymers utilizing pillar[5]arene-based host-guest interactions. Specifically, upon addition of Cu(2+) ions, the supramolecular polymer chains are crosslinked through metal-ligand interactions, resulting in the formation of a supramolecular polymer gel. Interestingly, this self-organized supramolecular polymer can be used as a novel fluorescent sensor for detecting Cu(2+) ions.

Supramolecular assembly-induced yellow emission of 9,10-distyrylanthracene bridged bis(pillar[5]arene)s

9,10-Distyrylanthracene has been introduced to bridge two pillarenes to form a dimeric host, which can assemble into a linear supramolecular polymer upon cooperatively binding to a neutral guest linker, exhibiting yellow fluorescence emission in solution and solid states.

Construction of a pillar[5]arene-based linear supramolecular polymer and a photo-responsive supramolecular network

A linear supramolecular polymer has been constructed from self-assembly of two complementary homoditopic monomers, an azobenzene-bridged pillar[5]arene dimer and a bisammonium salt, at high concentration based on the pillar[5]arene/secondary ammonium salt molecular recognition motif. This supramolecular polymer exhibited photo and pH dual-responsiveness. Polymer–oligomer and polymer–monomer transitions were reversibly regulated by UV/vis light irradiation and changing the solution pH, respectively. Furthermore, a photo-responsive supramolecular crosslinked liquid-crystalline polymer network based on the host–guest interactions between the azobenzene-bridged pillar[5]arene dimer and a secondary ammonium salt-functionalized poly(methyl acrylate) was fabricated.

Hydrodynamic Helical Orientations of Nanofibers in a Vortex

In this review article, I report our recent studies on spectroscopic visualizations of macroscopic helical alignments of nanofibers in vortex flows. Our designed supramolecular nanofibers, formed through self-assemblies of dye molecules, helically align in torsional flows of a vortex generated by mechanical rotary stirring of the sample solutions. The nanofiber, formed through bundling of linear supramolecular polymers, aligns equally in right- and left-handed vortex flows. However, in contrast, a one-handedly twisted nanofiber, formed through helical bundling of the supramolecular polymers, shows unequal helical alignments in these torsional flows. When the helical handedness of the nanofiber matches that of the vortex flow, the nanofiber aligns more efficiently in the flowing fluid. Such phenomena are observed not only with the artificial helical supramolecular nanofibers but also with biological nanofibers such as double-stranded DNA.

Hyperbranched Supramolecular Polymer of Tris(permethyl‐β‐cyclodextrin)s with Porphyrins: Characterization and Magnetic Resonance Imaging

AbstractA hyperbranched supramolecular polymer (HSP) is constructed based on the intermolecular inclusion complexation of bridged tris(permethyl‐β‐cyclodextrin) with MnIII‐porphyrin bearing poly(ethylene glycol) (PEG) side chains (MnIII‐TPP), and characterized by UV/vis absorption spectroscopy, isothermal titration calorimetry (ITC), NMR, dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM), respectively. The presence of permethyl‐β‐cyclodextrin can stabilize the low‐valent MnII‐TPP. In vitro cell experiment indicates that this HSP has no remarkable cellular toxicity against NIH 3T3 cells. In vitro MR imaging experiment indicates a slightly increased T1 relaxivity for this HSP compared to that for the linear supramolecular polymer.

High Degree of Polymerization in a Fullerene‐Containing Supramolecular Polymer

AbstractSupramolecular polymers based on dispersion forces typically show lower molecular weights (MW) than those based on hydrogen bonding or metal–ligand coordination. We present the synthesis and self‐assembling properties of a monomer featuring two complementary units, a C60 derivative and an exTTF‐based macrocycle, that interact mainly through π–π, charge‐transfer, and van der Waals interactions. Thanks to the preorganization in the host part, a remarkable log Ka=5.1±0.5 in CHCl3 at room temperature is determined for the host–guest couple. In accordance with the large binding constant, the monomer self‐assembles in the gas phase, in solution, and in the solid state to form linear supramolecular polymers with a very high degree of polymerization. A MW above 150 kDa has been found experimentally in solution, while in the solid state the monomer forms extraordinarily long, straight, and uniform fibers with lengths reaching several microns.

High Degree of Polymerization in a Fullerene‐Containing Supramolecular Polymer

Supramolecular polymers based on dispersion forces typically show lower molecular weights (MW) than those based on hydrogen bonding or metal-ligand coordination. We present the synthesis and self-assembling properties of a monomer featuring two complementary units, a C60 derivative and an exTTF-based macrocycle, that interact mainly through π-π, charge-transfer, and van der Waals interactions. Thanks to the preorganization in the host part, a remarkable log K(a)=5.1±0.5 in CHCl3 at room temperature is determined for the host-guest couple. In accordance with the large binding constant, the monomer self-assembles in the gas phase, in solution, and in the solid state to form linear supramolecular polymers with a very high degree of polymerization. A MW above 150 kDa has been found experimentally in solution, while in the solid state the monomer forms extraordinarily long, straight, and uniform fibers with lengths reaching several microns.