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Ken‐ichi Shinohara Tasuku Suzuki Takeshi Kitami Shingo Yamaguchi 《Journal of polymer science. Part A, Polymer chemistry》2006,44(2):801-809
We fabricated a micrometer‐long supramolecular chain in which π‐conjugated polyrotaxane was coupled. A new experimental setup was designed and constructed, and the simultaneous direct imaging of the structure and fluorescent function was achieved. Furthermore, we identified the formation of a polymer intertwined network and observed novel fluorescence due to a long‐range interaction via this intertwined network over a distance of 5 μm or more without quenching over 15 min in the near field. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 801–809, 2006 相似文献
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A new double betaine 1,1 '-(propane-1,3-diyl)dipyridinium-4-carboxylate L has been synthesized. Reaction of 1,1'-(propane-1,3-diyl)dipyridinium-4-carboxylate tetrahydrate 1 With Co(ClO4)2·6H2O leads to the formation of a new Co(Ⅱ) coordination compound,namely [Co(H2O)6]·2H2O·2L·2ClO4 2.The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction method. Crystal data for 1: monoclinic, space group C2/c, a =18.945(4), b = 7.700(2), c = 11.888(2) (A), β = 101.67(3)°, V = 1698.3(6) (A)3, Z = 4, F(000) =760.0, Dc = 1.402 g/cm3, the final R = 0.0607 and wR = 0.1607 for 950 observed reflections (I >2σ(I)); and those for 2: monoclinic, space group P21/c, a = 17.982(1), b = 15.879 (1), c = 7.0716(5) (A), β = 100.675(1)°, V = 1984.3(3) (A)3, Z = 4, F(000) = 1010.0, Dc = 1.631 g/cm3, the final R = 0.0316 and wR = 0.0896 for 3784 observed reflections (I >2σ(I)). Crystal structure analysis indicates that in 1, molecules of L in a "V-shaped" conformation are linked to chains sustained by O-H…O hydrogen bonds between carboxylate groups and solvent water molecules.The chains are joined by O-H…O and C-H…O hydrogen bonds to further expand into a three-dimensional structure. For 2, molecules of L in a "Z-shaped" conformation are linked by hydrogen bonds between carboxylate groups and aqua ligands to form a chain of loops running down the b axis. The (2D→2D) polythreading in compound 2 represents the mode of parallel interpenetration of 2D sheets, having polyrotaxane character. 相似文献
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Three cucurbit[6]uril (CB[6])-based polyrotaxanes [Cu(H2 C6N4)(CB[6])]Cl4·12H2O (1), [Co(H2 C6N4)(CB[6])]Cl4·14H2O (2) and [Ag(C6N4)(CB[6])]NO3·7H2O (3) are prepared using N,N′-bis(4-pyridylmethyl)-1,6-hexanediamine (C6N4) threading into CB[6]'s and metal ions' assistance. Single-crystal X-ray diffraction analyses reveal that polyrotaxanes 1, 2 and 3 all have 1D chain structure where 1 and 2 are linear and 3 has two shapes, linear and sawtooth, respectively. The effects of guest molecules, metal and counter ions as well as intermolecular weak interactions on the architectures of polyrotaxanes are discussed. 相似文献
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Jun Araki 《Journal of polymer science. Part A, Polymer chemistry》2011,49(10):2199-2209
Four types of ionic polyrotaxane (PR) derivatives, that is, carboxymethylated, sulfoethylated, diethylaminoethylated, and trimethylammoniohydroxypropylated PRs, were successfully prepared starting from the same PR consisting of poly(ethylene glycol) as an axis and α‐cyclodextrins as ring molecules. The structures of the ionic PR derivatives were analyzed by 1H and 13C nuclear magnetic resonance (NMR), attenuated‐total reflection Fourier transform‐infrared, and colloidal titration. Degrees of substitution of the ionic PRs were calculated from results of 1H NMR and colloidal titrations; both sets of results satisfactorily agreed. Cross‐linking of sulfoethylated and quaternized PRs yielded ionic slide‐ring gels carrying sulfoethyl and quaternary ammonium groups on the mobile cross‐links, respectively. The former gel showed intriguing phenomena, including a large degree of swelling of up to 1147, drastic change in its swelling ratio by the presence of electrolyte and bending under a moderate applied electric field (7 V/cm). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
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Supramolecular Polyelectrolyte Complexes of Bone Morphogenetic Protein‐2 with Sulfonated Polyrotaxanes to Induce Enhanced Osteogenic Differentiation
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Katsuya Hyodo Yoshinori Arisaka Satoshi Yamaguchi Tetsuya Yoda Nobuhiko Yui 《Macromolecular bioscience》2019,19(4)
Modulation of material properties and growth factor application are critical in constructing suitable cell culture environments to induce desired cellular functions. Sulfonated polyrotaxane (PRX) surfaces with immobilized vascular endothelial growth factors (VEGFs) are prepared to improve network formation in vascular endothelial cells. Sulfonated PRXs, whereby sulfonated α‐cyclodextrins (α‐CDs) are threaded onto a linear poly(ethylene glycol) chain capped with bulky groups at both terminals, are coated onto surfaces. The molecular mobility of sulfonated PRX surfaces is modulated by tuning the number of threading α‐CDs. VEGF is immobilized onto surfaces with varying mobility. Low mobility and VEGF‐immobilization reinforce cell proliferation, yes‐associated protein activity, and rhoA, pdgf, ang‐1, and pecam‐1 gene expression. Highly mobile surfaces and soluble VEGF weakly affect these cell responses. Network formation is strongly stimulated in vascular endothelial cells only on low‐mobility VEGF‐immobilized surfaces, suggesting that molecular mobility and VEGF immobilization synergistically control cell function. 相似文献
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In this study polyrotaxane (PR)‐based triblock copolymers were first synthesized via the atom transfer radical polymerization (ATRP) of N‐isopropylacrylamide initiated with the self‐assembly of a distal 2‐bromoisobutyryl end‐capped Pluronic 17R4 with a varying amount of α‐cyclodextrins (α‐CDs) in the presence of CuCl/PMDETA at 25°C in aqueous solution. The α‐CDs entrapped on the copolymer chain were then linked with hexamethylene diisocyanate to give rise to novel slightly cross‐linked polyrotaxanes (SCPRs) in DMF at 45°C. The structures of the PR‐based triblock copolymers and SCPRs were characterized by 1H NMR, 13C CP/MAS, GPC and TGA analyses. The number‐average molecular weight of the resulting SCPRs was nearly three and five times of their precursor after linking with a low polydispersity index range of 1.08–1.28. The thermo‐responsive transition of both PR‐based supramolecular polymers in aqueous solution was demonstrated by turbidity measurements and the self‐aggregated morphologies were also evidenced by TEM observations. 相似文献