120 research outputs found

    Receptor properties of calix[4]resorcinarenes toward tetramethylammonium and choline cations in micellar solutions of sodium dodecyl sulfate

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    Concentration range of solubilization of calix[4]resorcinarene (H 8L) in sodium dodecyl sulfate (SDS) micelles was found. The interaction of the deprotonated form of H8L (tetraanions [H4L] 4-) with tetramethylammonium (TMA) and choline cations in micellar solutions of SDS was studied by pH-metry and NMR spectroscopy. The concentration dependences of the change in the cloud point in a multicomponent system TMA (choline)-[H4L]4-SDS-tetrabutylammonium bromide were determined. A correlation of these dependences with host-guest binding processes was found. The sharp change in the cloud points of the corresponding micellar solutions in concentration regions of TMA (0-5.10-4 mol L -1) and choline (0-1.1.10-3 mol L-1) is caused by the formation of inclusion complexes TMA (choline)-[H4L] 4- at the interface of the aqueous and micellar pseudophases. © 2006 Springer Science+Business Media, Inc

    Effect of silica coating and further silica surface decoration by phospholipid bilayer on quenching of Tb(III) complexes by adrenochrome

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    © 2015 Elsevier B.V. Abstract The present report introduces regularities and mechanisms of Tb(III)-centered luminescence quenching by adrenochrome for Tb(III)-p-sulfonatothiacalix[4]arene complexes in the aqueous solutions and the same complexes doped into silica nanoparticles. The choice of adrenochrome (the oxidized form of adrenaline) as quencher originates from its quenching effect on the Tb(III)-centered luminescence, which discriminates it from adrenaline and dopamine. The quenching through dynamic mechanism of the Tb(III) complexes in the solutions results from their concentration induced collision with adrenochrome molecules. The quenching of the Tb(III)-doped silica nanoparticles also occurs through dynamic mechanism, although it is insignificant due to the shielding effect of the silica surface. The inclusion of the Tb(III)-doped silica nanoparticles into phospholipid bilayers influences the quenching of the Tb(III)-centered luminescence by adrenochrome due to its binding with the bilayers deposited onto silica nanoparticles

    Synthesis and structure of new 2-aryl-substituted pyrrolidines containing phosphine oxide group

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    © 2018 2-Aryl-substituted pyrrolidines containing phosphine oxide group have been obtained by the reaction of P-(4,4-diethoxybutylaminomethyl)- P,P-di-p-tolylphosphine oxide with polyatomic phenols

    Supramolecular systems based on amidoammonium and amidoaminocalix[4]resorcinarenes and polyacrylic acid

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    © 2015 Elsevier B.V. In the solutions of polyacrylic acid (PAA) the amphiphilic calix[4]resorcinarenes 1-. 10 and their complexes with Methyl Orange (MO) form binary (. 1-. 10)-PAA and tertiary (. 2-. 10). -MO-PAA supramolecular complexes which are water-soluble in the case of amidoammonium (. 1-. 5) and water-insoluble in the case of amidoamino (. 6, 7) or amido(dimethylamino) (. 8-. 10) calixresorcinarenes. Almost 90% of removal of MO from the aqueous solution is achieved by the formation of the water-insoluble systems (. 6-. 10)-m{cyrillic}O{cyrillic}-PAA. In aqueous solution the particles of the (. 1-. 5)-PAA systems have average hydrodynamic diameters which values vary depending on the length of the alkyl substituents of macrocycles

    Stable complexes of tertiary ammonia derivative of phenothiazine with tertramethylsulfonated resorcin[4]arenes obtained under substoichiometric conditions

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    Eight water insoluble complexes of tetramethylsulfonated calix[4]resorcinarenes 1 and 2 (-CH3 and -C5H 11) with phenothiazine derivative, 3, were obtained under substoichiometric conditions by mixing aqueous solutions of the initial reagents. It was found that complexation of cationic 3 by macrocycles was provided by both Coulomb interaction with the negative sulfonato-groups on the upper rim and by cation-π interactions with the aromatic cavity. The complexes precipitated and, therefore, were studied in organic solvents-DMSO, CD3OD, and CDCl3 using IR-, UV-, and NMR- spectroscopy. Formation of the complexes accompanied by gradual dehydratation of the host-estimated quantity of water in the complexes decreased with increase of the initial concentration of 3. Driving forces of precipitation and complexation, the role of water coordinated by the hosts, and distribution of phenothiazine derivative between two kinds of binding sites are discussed. © 2007 Springer Science+Business Media, Inc

    Metal-polymer complexes of cobalt(II) and Copper(II) with hyperbranched polyester polycarboxylic acids

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    Hyperbranched polyester polycarboxylic acids of the second and third generations for use as high-efficiency complexing agents are synthesized. On the basis of these compounds, new metal-polymer complexes of cobalt(II) and copper(II) are prepared for the first time. As evidenced by IR and ERR studies, the central atom in these metal polycarboxylates occurs in the axially symmetric system MO6. The thermal stability of polymer copper complexes is improved with increases in the content of metal ions, the degree of functionalization, and the generation number of the polyacid platform. © 2013 Pleiades Publishing, Ltd

    Supramolecular nanoscale systems based on amphiphilic tetramethylensulfonatocalix[4]resorcinarenes and cationic polyelectrolyte with controlled guest molecule binding

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    © 2016 Informa UK Limited, trading as Taylor & Francis GroupThe water-soluble tetramethylensulfonatocalix[4]resorcinarene with methyl (C1) and pentyl (C5) substitutes on the lower rim forms colloid nanoscale aggregates with poly(diallyldimethylammonium chloride) (PDDA) in aqueous solutions. The size and stability of nanoparticles depend on concentrations of the components and their ratio in the ‘calixarene-polymer’ system. Ternary supramolecular complexes «polymer–macrocycle–guest molecule L-tryptophan (Trp) in conditions of spontaneous pH (3.80 and 4.78 for C1-PDDA and C5-PDDA systems, respectively) in an aqueous solution and in phosphate buffer (pH 7) were investigated by fluorescence method. The addition of the third component – PDDA – to the «non-aggregated C1–Trp» associates leads to the release of Trp in all studied conditions. The possibility of the «binding–release» process of L-tryptophan in «C5–Trp» associates after PDDA addition in the ternary complex is achieved and controlled by the structure of the macrocyclic self-associates and pH conditions

    Nanoassociates of amphiphilic carboxy-calixresorcinarene and cetylpyridinuim chloride: The search of optimal macrocycle/surfactant molar ratio

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    © 2018 Elsevier B.V. Here we present the supramolecular surfactant-macrocycle system which properties are independent on system composition in the wide range of components concentrations. The study of the interaction of octacarboxy-tetra(p-phenylene-oxy-pentyl)calixresorcinarene (C5R) and cetylpyridinuim chloride (CPC) in mixed aqueous solutions were performed by dynamic light scattering and electrophoretic methods,1H and FT-PGSE NMR methods, absorption and fluorescence spectroscopy, and TEM. The variation of CPC/C5R molar ratio from 30/1 to 10/1 leads to the formation of nanoassociates with similar composition, size, surface potential value, and improved (in compare with CPC) solubilizing properties. The preparation of mixed supramolecular systems which properties are independent on system composition in the wide range of components concentrations is an elegant example of the producing of colloidal materials with the required morphology and properties

    Supramolecular nanoscale systems based on amphiphilic tetramethylensulfonatocalix[4]resorcinarenes and cationic polyelectrolyte with controlled guest molecule binding

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    © 2016 Informa UK Limited, trading as Taylor & Francis Group.The water-soluble tetramethylensulfonatocalix[4]resorcinarene with methyl (C1) and pentyl (C5) substitutes on the lower rim forms colloid nanoscale aggregates with poly(diallyldimethylammonium chloride) (PDDA) in aqueous solutions. The size and stability of nanoparticles depend on concentrations of the components and their ratio in the ‘calixarene-polymer’ system. Ternary supramolecular complexes «polymer–macrocycle–guest molecule L-tryptophan (Trp) in conditions of spontaneous pH (3.80 and 4.78 for C1-PDDA and C5-PDDA systems, respectively) in an aqueous solution and in phosphate buffer (pH 7) were investigated by fluorescence method. The addition of the third component–PDDA–to the «non-aggregated C1–Trp» associates leads to the release of Trp in all studied conditions. The possibility of the «binding–release» process of L-tryptophan in «C5–Trp» associates after PDDA addition in the ternary complex is achieved and controlled by the structure of the macrocyclic self-associates and pH conditions

    Novel thermoresponsive water-soluble oligomers based on amphiphilic calixresorcinarenes

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    © 2017 Informa UK Limited, trading as Taylor & Francis Group.Novel water-soluble thermoresponsive oligomers TO1 and TO2 were obtained by reaction of amidoamine tetramethylcalixresorcinarenes (C1) and tetrapentylcalixresorcinarenes (C5) with ethylene glycol diglycidyl ether. The compounds were characterised by 1H and FT-PGSE NMR, FTIR, static light scattering and elemental analysis. The thermoresponsive properties of oligomers were investigated by spectrophotometry, DLS, FT-PGSE NMR and TEM. The cloud points of oligomers (43 °C for TO1 (5 mg/ml) and 41 °C for TO2 (1.2 mg/ml), respectively) were determined. The influence of salts effect on TO2 cloud points was investigated. The binding of anti-inflammatory drug naproxen (Nap) at 20 °C by TO1 and TO2 and its partial release at cloud points of oligomers in aqueous solution are observed using fluorescence and FT-PGSE NMR methods. New example of creating of thermoresponsive macrocyclic systems on the basis of amidoamine calixresorcinarenes with possibility of substrate binding and release under the influence of termo-stimuli in an aqueous solution was shown
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