Abstract Cyclodextrins are frequently used as building blocks, because they can be linked both covalently and noncovalently with specificity. Thus one, two, three, seven, fourteen, eighteen, or twenty substituents have been to one β‐cyclodextrin molecule in a regioselective manner. Furthermore, may serve organic host molecules. Their internal cavity is able accommodate two guest Conversely, suitable molecules thread many (one hundred more) cyclodextrin rings. The resulting supramolecular...

Another form of molecular self-assembly—the threading and unthreading ring-shaped molecules on a polymer chain (represented schematically here) was studied by NMR spectroscopy followed qualitatively for the formation polymeric inclusion compounds made up cyclodextrins poly-(iminooligomethylene)s. The structures are proven their conversion to polyrotaxanes.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of poly(diacetylenes) in solutionGerhard Wenz, Michael A. Mueller, Manfred Schmidt, and Gerhard WegnerCite this: Macromolecules 1984, 17, 4, 837–850Publication Date (Print):April 1, 1984Publication History Published online1 May 2002Published inissue 1 April 1984https://doi.org/10.1021/ma00134a052RIGHTS & PERMISSIONSArticle Views515Altmetric-Citations239LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum full text article...

Amino-terminated self-assembled monolayers on SiO2 surfaces were obtained by means of a simple silylation method. The thickness the was measured with ellipsometry. Washing tests strong solvents indicated that amino-silane is covalently bonded to silica surface. are very flat and homogeneous, as shown atomic force microscopy. Contact angle measurements showed such interact quickly air impurities should be used just after silylation. adhesion between amino-terminated surface gold evidenced...

Abstract Cyclodextrine werden gerne als Bausteine eingesetzt, da sie sich gezielt sowohl kovalent, auch nichtkovalent verknüpfen lassen. So wurden an ein β‐Cyclodextrinmolekül regioselektiv ein, zwei, drei, sieben, vierzehn, achtzehn oder zwanzig Substituenten kovalent gebunden. sind zudem organische Wirtmoleküle. In ihrem Innenraum finden zwei Gastmoleküle Platz. Umgekehrt können viele (hundert und mehr) Cyclodextrinmoleküle auf passendes Gastmolekül aufgefädelt werden. Solche...

The first preparation of thin films cellulose itself is reported. Cellulose exhibits excellent wetting behavior, extremely stable against oxidation and other chemical degradation in thin‐film form would have a number applications. method involves the LB trimethylcellulose (see Figure) situ conversion these on silicon substrates to cellulose. magnified image

Several different cyclodextrinthiol derivatives have been immobilized on gold surfaces through a chemisorption process to form films which exhibit significantly features. Three monothiolated cyclodextrin with spacers between the cavity and thiol group mixture of multithiolated cyclodextrins were synthesized characterized. Chemisorption these compounds onto gave investigated by Fourier transform infrared (FTIR) spectroscopy, time-of-flight mass spectrometry, contact angle measurements,...

The kinetics of the inclusion ionene-6,10 (3b) dibromide and its monomeric model, 1,10-bis(trimethylammonium)decane (5) diiodide, by α-cyclodextrin (1a) were investigated 1H NMR spectroscopy in an aqueous solution. monomer 5 is unusually slow shows a high activation energy, Ea = 63 kJ mol-1, which was attributed to steric hindrance for threading caused terminal trimethylammonium groups. Microcalorimetric titration with 1a revealed stability constant, KS 1540 M-1, compound. Because kinetic...

Abstract Heptakis (3‐ O ‐acetyl‐2,6‐di‐ ‐pentyl)‐ß‐cyclodextrin is used as a chiral stationary phase in capillary gas chromatography. High enantioselectivity towards trifluoro‐acetylated α and β‐chiral amines, amino alcohols, α‐ β‐amino acid esters, cyclic trans‐diols observed. In contrast to polysiloxane phases, where hydrogen bonding interaction essential for enantiomer separation, cyclodextrins inclusion properties contribute enantioselectivity. This can be concluded from the separation...

Enantiomer separation by gas chromatography in a few minutes and at temperatures between 45 130°C is now possible for compounds which cannot form H‐bonds. For peralkylated or partially alkylated acylated cyclodextrins factors of 1.021 1.279 have been achieved. The enantioselectivity the stationary phase depends—at least partially—on inclusion effects.

Enantiomerentrennung durch Gaschromatographie in wenigen Minuten und bei Temperaturen zwischen 45 130°C ist nun für Verbindungen, die keine H‐Brücken bilden können, möglich. An peralkylierten oder partiell alkylierten acylierten Cyclodextrinen wurden Trennfaktoren 1.021 1.279 erreicht. Die Enantioselektivität der stationären Phase beruht – zumindest teilweise auf Inclusionseffekten.

The inclusion of volatile derivatives benzene and cyclohexane in β-cyclodextrin (β-CD), hydroxypropyl-β-CD, hydrophilic β-CD-thioethers was investigated by static headspace gas chromatography (HS-GC) molecular modelling. obtained binding constants strongly increase with the amount space filling CD cavity salt concentration. β-CD thioethers show a 3-10 times higher potential than native β-CD.

Abstract A hydrophobic starch derivative is used for safe and enhanced delivery of anticancer agents. The synthesis characterization propyl with a controlled degree substitution to modulate the release encapsulated drug reported. application this polymer formulating nanoparticles docetaxel, an anti‐cancer agent effective against numerous types cancers but possessing intrinsic formulation difficulties described. solvent emulsification/diffusion technique optimized respect several parameters....

Given the present high incidence of melanoma and skin cancer, interest in potential drugs plant origin has increased significantly. Pentacyclic lupane-type triterpenes are widely distributed plants, offering numerous pharmacological benefits. Betulin is an important compound bark Betula pendula Roth therapeutic properties, including antitumor activities. Its biological effect limited by its poor water solubility, which can be improved cyclodextrin complexation. The best results have been...

Abstract A host polymer with pending β‐cyclodextrin side‐groups and a guest hydrophobic 4‐ tert ‐butylanilide side groups were synthesized by polymeranalogous reactions starting from poly[(maleic anhydride)‐ alt ‐(isobutene)] ( M̄ w = 60000). The inclusions of both polymers complementary monomeric guests hosts are proven microcalorimetry. interaction the in aqueous solution is accompanied tremendous increase viscosity.

Molecular nylon threads that are completely encased by cyclodextrin molecules (see sketch below) can be synthesized solid-state polycondensation of α,ω-amino acids in channellike inclusion compounds. Since the polyamide chains covered with cyclodextrins, they soluble water, but only for a limited time, because rings tend to slowly unthread some extent.

Abstract An efficient synthesis of a cyclodextrin polymer by polymer‐analogous reaction lithium β‐cyclodextrinate with poly[( N ‐vinyl‐2‐pyrrolidinone)‐ co ‐(maleic anhydride)] is described. Because highly water‐soluble, its binding guests, like 1‐adamantanamine and l‐adamantanecarboxylic acid, could be investigated titration microcalorimetry. All moieties are accessible the guest within polymer, but constants slightly lower than those for native β‐cyclodextrin. Binding influenced Coulomb...

The complexation of cations by lipophilic cyclodextrins opens new preparative possibilities. This was shown in the first synthesis a [2]-rotaxane with participation cyclodextrin. A bipyridinium unit quaternized on one side complexed heptakis(3-O-acetyl-2,6-di-O-butyl)-β-cyclo-dextrin and then at second N atom. rotaxane, here schematically, unequivocally identified mass spectrometry NMR spectroscopy.

Eine weitere Form der molekularen Selbstorganisation , das Auf– und Abfädeln von ringförmigen Molekülen auf eine Polymerkette (im Bild rechts schematisch dargestellt) konnte bei Bildung polymerer Einschlußverbindungen aus Cyclodextrinen Poly(imino‐oligomethylenen) NMR‐spektroskopisch beobachtet qualitativ verfolgt werden. Die Strukturen polymeren lassen sich durch polymeranaloge Umsetzungen zu Polyrotaxanen beweisen. magnified image