WorldWideScience

Sample records for calixarenes

  1. Calixarene-supported clusters

    DEFF Research Database (Denmark)

    Taylor, Stephanie M.; McIntosh, Ruaraidh D.; Piligkos, Stergios

    2012-01-01

    A combination of complementary cluster ligands results in the formation of a new calixarene-supported ferromagnetic [Mn(5)] cage that displays the characteristic bonding modes of each support.......A combination of complementary cluster ligands results in the formation of a new calixarene-supported ferromagnetic [Mn(5)] cage that displays the characteristic bonding modes of each support....

  2. Oxyfunctionalization of calixarene quinone rings.

    Science.gov (United States)

    Troisi, Francesco; Citro, Lucia; Gaeta, Carmine; Gavuzzo, Enrico; Neri, Placido

    2008-04-03

    The epoxidation of quinone rings of calixquinones represents a valid route for the introduction of oxygenated functionalities into the de-tert-butylated calixarene walls originating cis-diepoxy-p-dione moieties. Carbonyl reduction of these systems leads to hybrid calixarenes containing dianhydroinositol moieties (calixinositols) belonging to the calixcyclitols family. The regio- and stereochemistry of these derivatives was determined by 2D NMR studies, in conjunction with MM3 calculations and X-ray crystallography.

  3. Cyclometallation in calixarenes: Synthesis and structural ...

    Indian Academy of Sciences (India)

    Administrator

    phosphite-II, unprecedented in calixarene chemistry. Structural studies reveal that the aryl rings of the phenolic substituents in the cyclopalladated complex-II are oriented perpendicular to each other unlike in the case of the calixarene bisphosphite ligand-I although in both the compounds the calixarene framework adopts a ...

  4. Moulding calixarenes for biomacromolecule targeting.

    Science.gov (United States)

    Giuliani, Marta; Morbioli, Ilaria; Sansone, Francesco; Casnati, Alessandro

    2015-09-28

    After their successful use as a preorganized platform for the preparation of receptors for metal ions and small neutral molecules over the last 15 years, calixarenes are enjoying a renaissance of popularity as scaffolds for ligands that are able to efficiently and selectively target macromolecules such as proteins/enzymes, nucleic acids and lipids. This feature article summarizes the peculiar factors characterizing the calixarene structure and properties, as well as outlines the main rules that can be used to turn such macrocycles into efficient and successful ligands for these classes of biomacromolecules. Factors that affect the multivalent properties of calixarenes, such as the size, conformation and stereochemical presentation of binding groups or their amphiphilicity and hybrid character, are described in detail with the use of a few selected examples from the literature. Perspectives and applications of these ligands in bionanotechnology and nanomedicine, such as protein sensing and inhibition, gene-delivery, targeted drug-delivery and cell imaging, are also discussed.

  5. Gas Sorption and Storage Properties of Calixarenes

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Rahul S.; Banerjee, Debasis; Atwood, Jerry L.; Thallapally, Praveen K.

    2016-12-01

    Calixarenes, a class of organic macrocyclic molecules have shown interesting gas sorption properties towards industrially important gases such as carbon di-oxide, hydrogen, methane and acetylene. These macrocycles are involved in weak van der Waals interaction to form multidimensional supramolecular frameworks. The gas-diffusion and subsequent sorption occurs due to a cooperative behavior between neighboring macrocycles. Furthermore, the flexibility at the upper rim functional group also plays a key role in the overall gas uptake of calixarene. In this book chapter, we give a brief account of interaction and diffusion of gases in calixarene and selected derivatives.

  6. Rocco Ungaro, 40 years of Calixarene chemistry

    NARCIS (Netherlands)

    Reinhoudt, David

    2016-01-01

    During the Calix2015 conference that took place in Giardini Naxos in July of this year, the first C. David Gutsche Award for Calixarene Chemistry was awarded to one of the founders of the field, Professor Rocco Ungaro of the University of Parma. In this paper, Rocco Ungaro’s seminal contributions to

  7. A bis-calixarene from olefin metathesis

    Directory of Open Access Journals (Sweden)

    Shimelis T. Hailu

    2012-06-01

    Full Text Available A ring-closing olefin metathesis reaction of tetrakis(allyloxycalix[4]arene gave the bis calixarene, (15E,40E,60E-65,74-bis(prop-2-en-1-yloxy-13,18,38,43,58,63-hexaoxadodecacyclo[28.26.8.720,36.111,45.151,55.05,57.07,12.019,24.026,64.032,37.044,49.168,72]tetraheptaconta-1,3,5(57,7,9,11,15,19(24,20,22,26,28,30(64,32,34,36,40,44(49,45,47,51,53,55(65,60,68,70,72(74-heptacosaene, C74H68O8. It is a cage formed from two calix[4]arene units joined by butenyl groups at three of the O atoms on the narrow rim. The fourth O atom on each calixarene unit is joined with an allyl group. Each of the calix[4]arene units has a flattened cone conformation in which the allyloxy-substituted aryl group and the opposite aryl group are close together and almost parallel [dihedral angle between planes = 1.09 (11°], and the other two aryl groups are splayed outward [dihedral angle between planes = 79.53 (11°]. No guest molecule (e.g. solvent was observed within the cage. The alkene C atoms of one of the links between the calixarene moieties are disordered over two orientations with occupancies of 0.533 (9 and 0.467 (9.

  8. Calixarene-monophosphines as supramolecular chelators.

    Science.gov (United States)

    Sameni, Soheila; Lejeune, Manuel; Jeunesse, Catherine; Matt, Dominique; Welter, Richard

    2009-10-14

    The calix[4]arenes 5-diphenylphosphino-17-R1-11,23-diR2-25,26,27,28-tetrapropoxycalix[4]arene (1, R1 = R2 = Br; 2, R1 = Br, R2 = H; 3, R1 = R2 = p-tolyl; 4, R1 = p-tolyl, R2 = H; 5, R1 = R2 = H; 20, R1 = p-tolyl, R2 = H), all bearing a diphenylphosphino group attached to the calixarene upper rim, have been synthesised starting from 5,11,17,23-tetrabromo-25,26,27,28-tetrapropoxycalix[4]arene. Reaction of 1-5 with [RuCl2(p-cymene)]2 leads quantitatively to monophosphine complexes, [RuCl2(p-cymene)L], in which the endo-oriented ruthenium atom unit sits inside the cone delineated by the four phenoxy rings. The particular orientation of the P-Ru vector appears to result from pi-pi interactions between the p-cymene ligand and two aromatic cavity walls. Overall, in each case the calixarene end of the ligand behaves as a supramolecular receptor towards the Ru(p-cymene) fragment. Formation of complexes with exo-oriented P-M bonds were observed in the complexes cis-[PtCl2 x 1(2)] and in [RuCl2(p-cymene) x 20]. As shown by a variable temperature study carried out on [RuCl2(p-cymene) x 3], in which the ruthenium is embedded in an expanded cone, the p-cymene ring undergoes a fast oscillation about the Ru-arene bond which can be frozen out at low temperatures. Reaction of [RuCl2(p-cymene) x 3] with AgBF4 in CH3CN results in an intra-cavity reaction, with one chloride ligand being replaced by acetonitrile.

  9. Host-guest sensing by calixarenes on the surfaces.

    Science.gov (United States)

    Kim, Hyun Jung; Lee, Min Hee; Mutihac, Lucia; Vicens, Jacques; Kim, Jong Seung

    2012-02-07

    The present critical review reports on recent developments of optical nanoparticles based on the association of gold, silver, silica and quantum dots and calixarenes. These hybrid organic-inorganic compounds characterized by a thick organic layer self-assembled on the surface of a core of mineral surface atoms take advantage of the supramolecular recognition of luminescent calixarenes to fabricate nanodevices of nanoparticle size, capable of detecting metal cations, polyaromatic hydrocarbons and pesticides. Also presented is an explanation of the involvement of such nanoparticles in biochemical systems. This critical review provides an overview of their preparation, the manner in which they are characterized, and their use (108 references). This journal is © The Royal Society of Chemistry 2012

  10. Caesium extraction by calixarene molecules: Some aspects of extraction kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Simon, N.; Tournois, B.; Volle, G

    2004-07-01

    In the framework of the environment Code (2000 studies were developed to recover long-lived fission products (F.P.) from acidic highly radioactive effluents issuing the reprocessing of spent fuels, to destroy them by transmutation or to encapsulate them into specific matrices. Efforts had been directed towards caesium, particularly {sup 135}Cs, which is one of the most harmful fission products because of its long half life (more than 2.10{sup 6} years) and its mobility in repository. The flow-sheet will be included in the general scheme of long-lived radionuclide partitioning. It was decided to define a process based on liquid-liquid extraction. Crown-calixarenes molecules were chosen for process development. To refine the flowsheet diagram, it is necessary to know the rate constants of the implied chemical reactions involved in the extraction. This paper describes the first determination of rate constant in the Cs extraction with crown calixarenes. (authors)

  11. Calix 2007:9th International Conference on Calixarene Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Jeffery Davis

    2011-09-09

    The DOE funds helped support an International Conference, Calix 2007, whose focus was on Supramolecular Chemistry. The conference was held at the University of Maryland from August 6-9, 2007 (Figure 1). The conference website is at www.chem.umd.edu/Conferences/Calix2007. This biannual conference had previously been held in the Czech Republic (2005), Canada (2003), Netherlands (2001), Australia (1999), Italy (1997), USA (Fort Worth, 1995) Japan (1993) and Germany (1991). Calixarenes are cup-shaped compounds that are a major part of Supramolecular Chemistry, for which Cram, Lehn and Pederson were awarded a Nobel Prize 20 years ago. Calixarene chemistry has expanded greatly in the last 2 decades, as these compounds are used in synthetic and mechanistic chemistry, separations science, materials science, nanoscience and biological chemistry. The organizing committee was quite happy that Calix 2007 encompassed the broad scope and interdisciplinary nature of the field. Our goal was to bring together leading scientists interested in calixarenes, molecular recognition, nanoscience and supramolecular chemistry. We believe that new research directions and collaborations resulted from an exchange of ideas between conferees. This grant from the DOE was crucial toward achieving that goal, as the funds helped cover some of the registration and accommodations costs for the speakers.

  12. Fabrication of Calixarene Based Protein Scaffold by Electrospin Coating for Tissue Engineering.

    Science.gov (United States)

    Cagil, Esra Maltas; Ozcan, Fatih; Ertul, Seref

    2018-08-01

    In this study, calixarene was synthesized by using different functional groups as p-tert-butyl-Calix[4]arene ester and amides. Calixarene nanofibers were produced by electrospin coating. Protein immobilization onto the calixarene nanofibers was carried out with human serum albumin (HSA). The maximum amount of binding on produced three different calixarene nanofibers (DE, 2-AMP and 3-AMP) was compared by using a fluorescence technique for protein analysis. Result showed that maximum binding amount was found to be as 177.85 mg cm-2 for 3-AMP surface. The protein binding was also characterized by using SEM, TEM, AFM and FT-IR. From obtained results, calixarene-albumin nanofiber was also fabricated by spin coating using 3-AMP which has ability max binding of protein.

  13. Upper rim appended hybrid calixarenes via click chemistry.

    Science.gov (United States)

    Bew, Sean P; Brimage, Rebecca A; L'Hermite, Nathalie; Sharma, Sunil V

    2007-09-13

    We report the application of "click" chemistry for the synthesis of hybrid calixarenes appended on the upper rim with carbohydrate and N,C-protected alpha-amino acids. The chemoselective N- or C-deprotection of the alpha-amino acids and their subsequent transformation into dipeptides is described. The first example of a chemo-enzymatic synthesis on upper rim derived calix[4]arenes using trans-sialidase affords sialylated lactose calix[4]arenes. Our innovative chemo-enzymatic process paves the way for further applications.

  14. Development of a Selective Calixarene Sensor for Uranium

    Energy Technology Data Exchange (ETDEWEB)

    Evans-Thompson, C.; Field, S. E.; Jones, A. H.; Kan, M. J.; Hall, C. W.; Nicholson, G. P.

    2002-02-26

    Traditionally, measurements of uranium in wastewater have been obtained by laboratory based instrumentation, such as inductively coupled plasma spectroscopy, ion-chromatography and radiochemical methods. However, such methods and equipment, whilst offering excellent sensitivity and reproducibility, are far too large and heavy to be portable. Therefore, there has been a lot of interest in developing a portable sensor to carry out uranium measurements. This work describes how a class of molecule called calixarenes have been used to develop a sensing methodology for measuring uranium concentration at low levels. This has been achieved by taking the established coordinating properties of the calixarene molecule for uranium and then adding functionalities to the molecule to make it adhere to metal surfaces. This way, a layer of the uranophilic molecule has been prepared on electrode surfaces, one molecule thick. These electrodes have been shown to be sensitive to uranium between 5 and 300 parts per billion. Using these modified electrodes, a portable device has been developed, which potentially allows for measurement of uranium in the field. This sensor therefore presents a very significant advantage in that it allows for rapid determination of low levels of uranium in wastewater, whilst offering portability.

  15. Lanthanides and actinides extraction by calixarenes containing CMPO groups; Extraction des lanthanides et des actinides au moyen de calixarenes portant des groupements CMPO

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Carrera, A

    2001-07-01

    In the framework of the French program SPIN concerning the radioactive waste management, researches are performed to develop processes allowing the separation of long-lived radioisotopes in order to their transmutation or their specific conditioning. These studies deal with the extraction and the separation of trivalent lanthanides and actinides in acid solution. Many systems ''calixarene-diluent-aqueous phase'' are examined by extraction liquid-liquid and membrane transport. The extraction efficiency and the selectivity of the synthesized calixarene-CMPO and of the CMPO are compared with these cations, as the nitric acid extraction by these molecules. (A.L.B.)

  16. Calixarene methylene bisphosphonic acids as promising effectors of biochemical processes

    Directory of Open Access Journals (Sweden)

    S. V. Komisarenko

    2013-12-01

    Full Text Available This interdisciplinary study, performed with participation of research workers of Palladin Institute of Biochemistry and Institute of Organic Chemist­ry of NAS of Ukraine, is devoted to analysis of biochemical effects of some calixarene methylene bisphosphonic acids (cyclic phenol oligomers on two well-known biological phenomenons – Mg2+-dependent ATP hydrolysis (myosin subfragment-1 of myometrium smooth muscle was used as an example and fibrin polymerization. Calix[4]arene С-97 (calix[4]arene methylene bisphosphonic acids is a macrocyclic substance, which contains intramolecular highly ordered lipophilic cavity formed by four aromatic rings, one of which is functionalized at the upper rim with methylene bisphosphonic group. At concentration of 100 µM, this substance was shown to effectively inhibit ATPase activity of pig myometrium myosin subfragment-1 (inhibition coefficient І0.5 = 83 ± 7 µM. At the same time, this calix[4]arene causes significant (vs. control increase of myosin subfragment-1 hydrodynamic diameter, which may indicate formation of an intermolecular complex between calixa­rene and myosin head. Computer simulation methods (docking and molecular dynamics with addition of grid technologies enabled to elucidate the grounds of intermolecular interactions between calix[4]arene С-97 and myometrium myosin subfragment-1, that involve hydrophobic, electrostatic and π-π-stacking interactions, some of which are close to the ATPase active centre. In view of the ability of calixarenes to penetrate into the cell and their low toxicity, the results obtained may be used as a basis for further development of a new generation of supramolecular effectors (starting from the above mentioned substances, in particular calix[4]arene С-97 for regulation of smooth muscle contractile activity at the level of ATP dependent actin-myosin interaction. Calix[4]arenes bearing two or four methylenebisphosphonic acid groups at the macrocyclic upper

  17. A calixarene-based ion-selective electrode for thallium(I) detection

    Energy Technology Data Exchange (ETDEWEB)

    Chester, Ryan [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Sohail, Manzar [Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, Queensland 4556 (Australia); Ogden, Mark I.; Mocerino, Mauro [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Pretsch, Ernö [ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Universitätstrasse 16, CH-8092, Zürich (Switzerland); De Marco, Roland, E-mail: rdemarc1@usc.edu.au [Nanochemistry Research Institute, Department of Chemistry, Curtin University, GPO Box U1987, Perth, Western Australia 6845 (Australia); Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, Queensland 4556 (Australia)

    2014-12-03

    Highlights: • Tuning of metal binding cavities in thallium(I) calixarene ionophores. • Novel calixarene-based ionophores with improved selectivity for thallium(I). • Sandwich membrane characterization of thallium(I) binding in novel calixarenes. • Improved selectivity and sensitivity with novel thallium(I) calixarene ionophores. • Solid contact ion-selective electrodes for novel thallium(I) calixarene ionophores. - Abstract: Three new calixarene Tl{sup +} ionophores have been utilized in Tl{sup +} ion-selective electrodes (ISEs) yielding Nernstian response in the concentration range of 10{sup −2}–10{sup −6} M TlNO{sub 3} with a non-optimized filling solution in a conventional liquid contact ISE configuration. The complex formation constants (log β{sub IL}) for two of the calixarene derivatives with thallium(I) (i.e. 6.44 and 5.85) were measured using the sandwich membrane technique, with the other ionophore immeasurable due to eventual precipitation of the ionophore during these long-term experiments. Furthermore, the unbiased selectivity coefficients for these ionophores displayed excellent selectivity against Zn{sup 2+}, Ca{sup 2+}, Ba{sup 2+}, Cu{sup 2+}, Cd{sup 2+} and Al{sup 3+} with moderate selectivity against Pb{sup 2+}, Li{sup +}, Na{sup +}, H{sup +}, K{sup +}, NH{sub 4}{sup +} and Cs{sup +}, noting that silver was the only significant interferent with these calixarene-based ionophores. When optimizing the filling solution in a liquid contact ISE, it was possible to achieve a lower limit of detection of approximately 8 nM according to the IUPAC definition. Last, the new ionophores were also evaluated in four solid-contact (SC) designs leading to Nernstian response, with the best response noted with a SC electrode utilizing a gold substrate, a poly(3-octylthiophene) (POT) ion-to-electron transducer and a poly(methyl methacrylate)–poly(decyl methacrylate) (PMMA–PDMA) co-polymer membrane. This electrode exhibited a slope of 58.4 mV decade

  18. Study of the alkaline cations complexation by photo-isomerizable calixarenes; Etude de la complexation de cations alcalins par des calixarenes photoisomerisables

    Energy Technology Data Exchange (ETDEWEB)

    Reynier, N.

    1996-04-25

    The first step to reduce the volume and the toxicity of radioactive waste coming from the spent fuel reprocessing is to separate long life radioisotopes from others ones with a shorter period. The aim of this study is to show that the control of the two phenomenons, complexation of the cation by the calixarenes and its de-complexation, can be envisaged by the introduction on the molecule of a chromophore group, azo benzene, able to modify the complexing site structure of the calixarenes with an isomerization trans-cis induced by ultraviolet radiation, and isomerization cis-trans thermally induced by a visible radiation. (N.C.). 112 refs., 78 figs., 23 tabs.

  19. Quantum mechanical calculations of conformationally relevant 1H and 13C NMR chemical shifts of calixarene systems.

    Science.gov (United States)

    Bifulco, Giuseppe; Gomez-Paloma, Luigi; Riccio, Raffaele; Gaeta, Carmine; Troisi, Francesco; Neri, Placido

    2005-12-22

    [graphs: see text] QM GIAO calculations of 13C and 1H chemical shift values of the ArCH2Ar group have been performed, using the hybrid DFT functional MPW1PW91 and the 6-31G(d,p) basis set, on some representative calixarenes and on a series of simplified calixarene models allowing derivation of chemical shift surfaces versus phi and chi dihedral angles. A good reproduction of experimental data was obtained. The applicability of chemical shift surfaces in the study of calixarene conformational features is illustrated.

  20. Calixarene-based molecular capsule from olefin metathesis

    Directory of Open Access Journals (Sweden)

    Shimelis T. Hailu

    2013-07-01

    Full Text Available The reaction of tetrakis(allyloxycalix[4]arene with the first-generation Grubbs catalyst, followed by catalytic hydrogenation, gave the novel bis-calixarene 15,20,46,51,64,69,74,79-octaoxatridecacyclo[32.28.8.83,28.113,53.122,44.09,14.021,26.038,70.040,45.052,57.059,63.07,80.032,73]octaconta-1(63,3,5,7(80,9(14,10,12,21,23,25,28(73,29,31,34,36,38(70,40,42,44,52,54,56,59,61-tetracosaene benzene monosolvate, C72H72O8·C6H6. The structure consists of two calix[4]arene units connected by four-carbon chains at each of the four O atoms on their narrow rims, to form a cage. Each of the calix[4]arene units has a flattened cone conformation in which two of the opposite aryl groups are closer together and nearly parallel [dihedral angle between planes = 7.35 (16°], and the other two aryl groups are splayed outward [dihedral angle between planes = 72.20 (8°]. While the cavity contains no solvent or other guest molecule, there is benzene solvent molecule in the lattice. Two of the alkyl linking arms were disordered over two conformations with occupancies of 0.582 (3/0.418 (3 and 0.33 (4/0.467 (4. They were constrained to have similar metrical and thermal parameters.

  1. Size- and Stereo-specific Accommodation of Alkanes and Alkenes in Calixarene-based Microporous Solids

    OpenAIRE

    Ishii, Yusuke; NAKAYAMA, Naoki; Konishi, Katsuaki

    2007-01-01

    Hydrophobic micropores created in the crystal lattice of a calix[4]arene–polyoxometalate hybrid (C2-PW) selectively accommodated heptane rather than the branched homologues. The sorption properties were tunable by slight modification of the calixarene unit, whereby the recognition of E–Z stereochemistry of 2-heptene was achieved.

  2. Calixarene-stabilised cobalt nanoparticle rings: Self-assembly and collective magnetic properties

    DEFF Research Database (Denmark)

    Wei, A; Tripp, SL; Liu, J

    2009-01-01

    Calixarenes can be used to promote the self-assembly of thermoremanent cobalt nanoparticles into bracelet-like rings below 100nm in diameter. These kinetically stable assemblies are regulated by the equilibrium between enthalpic gain (dipole-dipole and long-range van der Waals interactions...

  3. Quantum mechanical calculations of conformationally relevant 1H and 13C NMR chemical shifts of N-, O-, and S-substituted calixarene systems.

    Science.gov (United States)

    Bifulco, Giuseppe; Riccio, Raffaele; Gaeta, Carmine; Neri, Placido

    2007-01-01

    QM GIAO calculations of (13)C and (1)H chemical shift values of the ArCH(2)Ar group in N-, O-, and S-substituted calixarene systems were performed with a hybrid DFT functional MPW1PW91 and 6-31G(d,p) basis set. A good reproduction of experimental data was obtained for some representative calixarenes and for a series of simplified calixarene models. This allowed the derivation of chemical shift surfaces versus phi and chi dihedral angles. The applicability of chemical shift surfaces in the study of calixarene conformational features is illustrated.

  4. [Spatial structure of the calixarene-aminophosphonic acids is important for their inhibition of the Na+,K(+)-ATPase activity in plasma membrane of smooth muscle cells].

    Science.gov (United States)

    Veklich, T O; Shkrabak, O A; Rodik, R V; Boĭko, V I; Kal'chenko, V I; Kosterin, S O

    2010-01-01

    It was found that calixarene C-107 (5,17-diamino(2-pyridyl)methylphosphono-11,23-di-tret-butyl-26,28-dihydroxy-25,27-dipropoxycalix[4]arene) could effectively reduce Na+,K(+)-ATPase activity of the myometrium cell plasmatic membranes (the value of the apparent constant of inhibition I0.5 was 33 +/- 4 nM) while it practically did not influence the "basal" Mg2(+)-ATPase activity of the same membrane. In comparative experiments, we have shown that the model calixarene C-150--the calixarene "scaffold" (26,28-dihydroxy-25,27-dipropoxycalix[4]arene), and the model compound M-3 (4-hydroxyaniline(2-pyridine)methylphosphonic acid)--a fragment of the calixarene C-107, had practically no influence on the enzymatic activities of Na+,K(+)-ATPase and Mg(2+)-ATPase over a wide range of concentrations. Hence, the influence of calixarene C-107 on Na+,K(+)-ATPase activity was caused by the joint action of two aminophosphonic substituents on the upper rim of the calixarene bowl. The isomer of calixarene C-107--calixarene C-160 (5,11-diamino(2-pyridyl)methylphosphono-17,23-di-tret-butyl-26,28-dihydroxy-25,27-dipropoxycalix[4]arene) also did not influence the Na+,K(+)-ATPase and Mg(2+)-ATPase activities of plasmatic membrane of myometrium cells. We carried out molecular modeling of calixarenes C-107 and C-160 and showed differences in interatomic distance between aminophosphonic substituents of mentioned calixarenes. We came to the conclusion that spatial structure of calixarene C-107, namely localization of two aminophosphonic substituents in 5,17 position of the upper rim of this calixarene, is crucial for inhibition of Na+,K(+)-ATPase activity. Using laser correlation spectroscopy it was found that the 100 microM solution of calixarene C-107 and 2.5% DMSO had microparticles with size range from 100 nm to 10 microm. Plasma membrane vesicles had average hydrodynamic diameter 401 +/- 17 nm, but after interaction of these vesicles with calixarene C-107 we have registered the creation of

  5. Catalytic consequences of the structural environment and electronics of Ti in grafted Ti-calixarenes

    Energy Technology Data Exchange (ETDEWEB)

    Notestein, Justin M.; Katz, Alexander; Iglesia, Enrique [University of California, Berkeley, CA (United States). Dept. of Chemical Engineering; Andrini, Leandro R.; Requejo, Felix G. [Universidad Nacional de La Plata (Argentina). Inst. de Fisica; Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina). Facultad de Ciencias Exactas. Dept. de Fisica; Kalchenko, Vitaly I. [National Academy of Sciences (Ukraine). Inst. of Organic Chemistry

    2008-11-15

    Calixarene-metal complexes provide the opportunity for fundamental studies to correlate basic characteristics and properties of molecules and atomic species. In particular because grafted Ti-calixarenes provide Ti centers with varying electron density and coordination but maintain accessible sites (active centers) with uniform structures and unrestricted access to reactants, they allow for a systematic approach to relating oxidation reactivity to Ti 3d occupancy, a descriptor of Lewis acid strength, and Ti coordination. Thus, the relationship between activity, geometry and concepts of electronics in catalysis can be revisited and clarified due to the well-defined nature of these Ti sites, allied to the chemical and local sensitivity of X-ray absorption techniques. (author)

  6. Calixarene dimers as host molecules for biologically important di- and oligophosphates.

    Science.gov (United States)

    Zadmard, Reza; Taghvaei-Ganjali, Saeed; Gorji, Banafsheh; Schrader, Thomas

    2009-09-01

    A dimeric calixarene, with an aliphatic C(6)-bridge and six anilinium head groups at its upper rim, preferably complexes diphosphates and oligonucleotides with more than 10 bonds between both anionic moieties. Free binding energies correlate with the length of the aliphatic bridge in a roughly linear fashion. The binding event, which is monitored by fluorescence titrations and competition experiments, relies on Coulomb interactions, as opposed to a nonpolar variant with tert-butyl instead of ammonium groups; here, hydrophobic forces prevail, rendering the calixarene dimer selective for less polar cofactors such as FAD. The best guest for the hexaanilinium dimer is found in ssDNA, which carries multiple copies of the optimal trinucleotide for maximum attraction towards the extended cationic host. The recognition event is also observed in the environment of a lipid monolayer, and provides a means to quantify dimer diphosphate interactions by measuring p/A shifts.

  7. Cs selective extraction from high level liquid wastes with crown calixarenes: Where are we today?

    Energy Technology Data Exchange (ETDEWEB)

    Simon, N.; Tournois, B.; Eymard, S.; Volle, G.; Rivalier, P.; Leybros, J.; Lanoe, J.Y.; Reynier-Tronche, N.; Ferlay, G.; Dozol, J.F

    2004-07-01

    This paper deals with the developments carried out around the caesium process these last years to prove its scientific feasibility, then to acquire technical feasibility.The crown-calixarenes molecules showed their efficiency towards selective Cs extraction and their superiority with respect to the traditional alkaline cations extraction systems: crown-ether molecules. After acquisition of experimental data, calculations of flow-sheet were carried out. Tests, first on simulated effluents, then on real effluents, demonstrated the scientific feasibility of the concept. The technical feasibility is currently in progress through the following studies: - hydrodynamic and transfer studies; - kinetics data are in progress; - calixarene molecule are known to be highly resistant molecules towards hydrolysis and radiolysis phenomena but regeneration studies have to be taken into account to define the industrial process. (authors)

  8. The Liquid-Liquid Extraction of Toxic Metals (Cd, Hg and Pb by Calixarenes

    Directory of Open Access Journals (Sweden)

    D. Max Roundhill

    2009-12-01

    Full Text Available Toxic metals (Cd, Hg and Pb are mostly present in the environment due to natural phenomenon and human activities as well. Exposure of these non-essential elements in the environment causes severe effects. They are known to cause problems in humans as well as in aquatic life. In this work, we demonstrate various studies regarding liquid-liquid extraction of selected ions with different functionalized calixarenes. This review article briefly discusses several molecular designs of calixarenes for divalent ion (Cd2+, Hg2+ and Pb2+ recognition; as well as the relationship between structure and selectivity of the macrocycles is elaborated. The article does not, however, attempt to cover all of the different approaches to these toxic metal ions extraction.

  9. Calixarenes and cations: a time-lapse photography of the big-bang.

    Science.gov (United States)

    Casnati, Alessandro

    2013-08-07

    The outstanding cation complexation properties emerging from the pioneering studies on calixarene ligands during a five-year period in the early 1980s triggered a big-bang burst of publications on such macrocycles that is still lasting at a distance of more than 30 years. A time-lapse photography of this timeframe is proposed which allows the readers to pinpoint the contributions of the different research groups.

  10. Calixcyclitols: a new class of polar hybrid hosts obtained by oxygenation of calixarene phenol rings.

    Science.gov (United States)

    Troisi, Francesco; Mogavero, Luca; Gaeta, Carmine; Gavuzzo, Enrico; Neri, Placido

    2007-03-01

    [structure: see text] The first examples of hybrid calixarene hosts containing cyclitol moieties (calixcyclitols) have been obtained by treatment with LiAlH4 of diepoxydiol and tetraepoxytetrol calix[4]arene derivatives. A 6-oxabicyclo[3:1:1]heptanetriol or a cyclohexanetetrol ring was obtained depending on the stereochemical features of the diepoxydiol moiety. Preliminary binding studies toward anionic guests showed a discrete selectivity of calixcyclitol 9 vs H2PO4-.

  11. [Comparative study of calixarene effect on Na+, K+ -ATPase activity in plasma membrane of contractile and mobile cells].

    Science.gov (United States)

    Veklich, T O; Koshechkova, N S; Rodik, R V; Boĭko, V I; Vorobets', Z D; Kosterin, S O

    2007-01-01

    The paper is devoted to comparative analysis of the influence of a new class of macrocyclic compounds - calixarens on enzymatic activity of two ATP-hydrolase systems localized in the plasmatic membrane of contractile (myocytes of the uterus) and mobile (spermatozoids) cells--Na+, K+ -ATPase and basal Mg2+ -ATPase. The experiments performed on plasmatic membrane suspensions of myometrium and spermatozoids treated with detergent the authors studied the influence of calixarens C-97, C-99, C-107 (identified by the codes), functionalized with fragments of alpha-hydroxyphosphonic, alpha-aminophosphonic and methylenbisphosphonic acids accordingly, on enzymatic activity. The results have shown that C-97 and C-107 calixarenphosphonic acids in 100 microM concentration (97-99%) inhibit Na+, K+ -ATPase activity in both cases almost completely. C-99 (100 microM) calixaren appeared to be less effective with regard of its influence on the enzymatic systems under study: in the case of plasmatic membranes of myometrium suspension the activity of Na+, K+ -ATPase was decreased by 84-88%, and in the case of spermatozoids suspension--just by 15-20% of the control. All the studied calixarens (for both objects) in the maximal concentration (100 microM) practically did not influence the activity of basal Mg2+ -ATP-ase. The calixarens inhibited the enzymatic activity of Na+, K+ -ATPase more effectively than ouabain: in the first case the value of apparent inhibition constant I(0,5) was 25-100 nM, and in the second case--20-100 microM. The inhibition influence of calixarens on Na+, K+ -ATPase activity is characterized by the phenomenon of negative cooperativity (Hill's coefficient nH plasmatic membranes of myometrium suspension is also characterized by negative cooperativity (nH 1). The above results show that the studied calixarens are effective inhibitors of Na+, K+ -ATPase plasmatic membrane of contractive and mobile cells (C-97, C-99, C-107 calixarens in case of myocytes of uterus, and

  12. Development of calixarenes, cyclodextrins and fullerenes as new platforms for anti-HIV drug design: an overview.

    Science.gov (United States)

    Luo, Zaigang; Xu, Xuemei; Zhang, Xiaomei; Hu, Liming

    2013-06-01

    The research and development of calixarenes, cyclodextrins and fullerenes, which constitute the major classes of supramolecular organic host compounds, have been quite rapidly developing, increasingly active and newly rising highlight interdisciplinary fields. Numerous efforts have been directed toward such molecules as new platforms for anti- HIV drug design. This work briefly reviewed the recent development of calixarenes, cyclodextrins and fullerenes as new chemical entities of distinct anti-HIV activities. It is hoped that this review will serve as a stimulant for new thoughts in the quest for rational designs of more active and less toxic biological molecules as anti-HIV drugs.

  13. Investigation of Basis set Effects on the NMR Chemical Shielding tensors data on (10, 10) SWCNTs Calixarene complexes

    OpenAIRE

    Roghieh Tarlani Bashiz; Elham Shabanzadeh

    2015-01-01

    Density functional theory calculations (DFT), as well as hybrid methods (B3LYP) and HF method for CNT-Calixarene complexes have been carried out to study structural stability. The geometry of the Calixarene has been optimized at DFT methods such as M062x B3LYP and HF methods with 6-31G, 6-31G*and 6-31G** basis sets. According to GIAO method, NMR parameters have been evaluated. The Gaussian quantum chemical package is used for all calculations. The gauge including atomic orbital (GIAO) approac...

  14. Structural assessment and catalytic consequences of the oxygen coordination environment in grafted Ti-calixarenes.

    Science.gov (United States)

    Notestein, Justin M; Andrini, Leandro R; Kalchenko, Vitaly I; Requejo, Felix G; Katz, Alexander; Iglesia, Enrique

    2007-02-07

    Calixarene-Ti complexes were grafted onto SiO2 (0.18-0.24 Ti nm-2) to form isolated and accessible Ti centers persistently coordinated to multidentate calixarene ligands. Grafted Ti-tert-butylcalix[4]arenes gave Ti K-edge absorption spectra with pre-edge features at 4968.6-4968.9 eV, independently of Ti surface density and of their use in epoxidation catalysis. The structure and reactivity of grafted Ti-calix[4]arenes were weakly dependent on thermal treatment below 573 K, and the relative epoxidation rates of trans- and cis-alkenes showed that calixarene ligands did not restrict access to Ti centers more than corresponding calcined Ti-SiO2 materials. For all materials, 13C NMR and UV-visible spectroscopies confirmed the presence of Ti-O-Si connectivity and identical ligand-to-metal transitions. Grafted Ti-homooxacalix[3]arene complexes, however, gave weaker pre-edge features at higher energies ( approximately 4969.5 eV), consistent with greater Ti 3d occupancy and coordination numbers greater than four, and 20-fold lower cyclohexene epoxidation rate constants (per Ti) than on calix[4]arene-based materials. These different rates and near-edge spectra result from aldehyde formation caused by unimolecular cleavage of ether linkages in homooxacalix[3]arene ligands during grafting, leading to higher coordination and electron density at Ti centers. Materials based on tert-butylcalix[4]arene and homooxacalix[3]arenes led to similar epoxidation rates and near-edge spectra after calcination, consistent with the conversion of both materials to isolated Ti centers with identical structure. These materials provide a systematic approach for relating oxidation reactivity to Ti 3d occupancy, a descriptor of Lewis acid strength, and Ti coordination, because they provide Ti centers with varying electron density and coordination, but maintain accessible active centers with uniform structure and unrestricted access to reactants.

  15. Highly efficient chirality transfer from diamines encapsulated within a self-assembled calixarene-salen host

    OpenAIRE

    Kleij, Arjan W.; Bandeira, Nuno A. G.; Luis Martínez-Rodríguez; Carles Bo

    2015-01-01

    Highly efficient chirality transfer from diamines encapsulated within a self-assembled calixarene-salen host A calix[4]arene host equipped with two bis-[Zn(salphen)] complexes self-assembles into a capsular complex in the presence of a chiral diamine guest with an unexpected 2:1 ratio between the host and the guest. Effective chirality transfer from the diamine to the calix-salen hybrid host is observed by circular dichroism (CD) spectroscopy, and a high stability constant K2,1 of 1.59×101...

  16. The Design and Development of a Regenerative Separatory Column Using Calixarenes as a Polymeric Backbone for the Purification of Water from Urine

    Science.gov (United States)

    Polk, M.

    1999-01-01

    The objective of this research project is to design calixarenes, cup-shaped molecules, with the specific binding sites to the sodium chloride and nitrogen containing components of urine, such as urea and uric acid, in urine. The following partition of the research accomplishes this objective: (1) functionalization of calixarene, (2) development of a calixarene based medium for the separatory process, (3) design of the column regeneration protocol. Work was also accomplished in the area of temperature sensitive paint (TSP). Research was undertaken to design a TSP with insulating propertites. An important part of this research project is to discover the thermal conductivity of polymers for TSP.

  17. [The calixarenes C-97 and C-107 stimulate influence of ouabain on the Na+,K+-ATPase activity in plasmatic membrane of smooth muscle cells].

    Science.gov (United States)

    Veklich, T O; Shkrabak, O A; Kosterin, S O; Rodik, R V; Cherenok, S O; Boĭko, S O; Boĭko, V I; Kal'chenko, V I

    2006-01-01

    In the experiments carried out with the suspension of the myometrium cell plasmatic membranes treated with 0.1% digitonin solution the authors investigated influence of the calix[4]arenes C-97 and C-107 (codes are shown) on ouabain effect on the Na+,K+-ATPase activity. It was shown that calixarenes in concentration 100 tiM inhibited by 97-98% the enzymatic Na+,K+-ATPase activity, while they did not practically influence on the basal Mg2+-ATPase activity, and suppressed much more effective than ouabain the sodium pump enzymatic activity: in the case of the action of the calixarenes the value of the apparent constant of inhibition I0.5 was < 0.1 microM while for ouabain it was 15-25 microM. The negative cooperative effect was typical of the inhibitory action of calixarenes, as well as ouabain: the value of Hills factor nH = 0.3-0.5 <1. The modelling compound M-3 (0.1 microM 4 microM)--a fragment of the calixarene C-107--did not practically influence the enzymatic activities as Na+,K+-ATPase and basal Mg2+-ATPase. Hence the influence of calixarene C-107 on the Na+, K+-ATPase activity is caused by cooperative action of two fragments M-3 and effect of calixarene bowl, rather than by simple action of the fragment M-3. Calixarenes C-97 and C-107, used in concentration corresponding to values of I0.5 (40 and 60 nM, accordingly), essentially stimulated inhibiting action of ouabain on the specific Na+, K+-ATPase activity in the memrane fraction. Under coaction of ouabain with calixarene C-97 or C-107 there was no additive effect of the action of these inhibitors on the Na+,K+-ATPase activity. Calixarene C-97 brought in the incubation medium in concentration of 10 nM not only led to inhibition of the Na+,K+-ATPase activity relative to control, but also simultaneously increased the affinity of the enzyme for the cardiac glycoside: the magnitudes of the apparent constant of inhibition I0.5 were 21.0 +/- 5.2 microM and 5.3 +/- 0.7 microM. It is concluded, that highly effective

  18. [Comparative study of in vitro and in vivo effect of ouabain and calixarene C107 on Na+,K(+)-ATPase activity in plasma membranes of rat hepatocytes].

    Science.gov (United States)

    Tsymbaliuk, O V; Kosterin, S O; Rodik, R V; Kal'chenko, V I

    2010-01-01

    The comparative study of influence of ouabain and calixarene C107, and the structure component of this calixarene--fragment M3, in the conditions of in vitro and chronic action in vivo on Na+, K(+)-ATPase activity was carried out on the fractions of plasmatic membranes (PM) of the rat hepatocytes. A general property in the conditions in vitro is the ability of calixarene C107 and ouabain (both substances were in the concentration of 1 mM) to inhibit PM Na+, K(+)-ATPase of rat hepatocytes. However, in the case of activities of calixarene C107 and ouabain in the conditions in vivo heterogeneous action on Mg2(+)-ATPase and Mg2+, Na+, K(+)-ATPase activities takes place: total activity in the conditions of injection of increased concentrations of ouabain remains without changes, but Mg2(+)-ATPase activity significantly grows; in analogous conditions under the action of calixarene C107 both these activities decrease twice in comparison with control. Both under the in vitro and in vivo conditions, M3 fragment (the structural component of C107) does not change the values of investigated enzymatic activities. The biochemical mechanisms of calixarene C107 action on Na+, K(+)-ATPase activity in PM of rat hepatocytes are discussed.

  19. Pyrene binding to persistent micelles formed from a dendro-calixarene.

    Science.gov (United States)

    Yihwa, Chang; Kellermann, Michael; Becherer, Miriam; Hirsch, Andreas; Bohne, Cornelia

    2007-05-01

    The formation of micelles of an amphiphilic dendro-calixarene (1) was studied using pyrene as a guest molecule. Steady-state fluorescence experiments were performed, which showed that pyrene is readily solubilized in the micelles and senses an environment with a moderate polarity. Time-resolved fluorescence measurements showed that pyrene in the micelles have two lifetimes, suggesting some compartmentalization of the guest within the micelles. Pyrene bound to the micelles is completely protected from the interaction with anionic species in the aqueous phase, due to the repulsion between the anions and the negatively charged micelles. Compared to conventional micelles, such as those formed with sodium dodecyl sulfate, micelles of 1 form at much lower concentrations of monomer.

  20. Study of the simultaneous complexation of a cation and of an anion using functionalized calixarenes; Etude de la complexation simultanee d'un cation et d'un anion par des calixarenes fonctionnalises

    Energy Technology Data Exchange (ETDEWEB)

    Moli, Ch. [CEA Cadarache, Dept. d' Etudes des Dechets, DED, 13 - Saint Paul lez Durance (France)]|[Universite Louis Pasteur, 67 - Strasbourg (France)

    2002-03-01

    The chemical reprocessing of irradiated nuclear fuels leads to the production of high-level radioactive liquid wastes which contain long-lived toxic radioelements. In the framework of the long-term management of these wastes, important research work is carried out for the separation of these radioelements for their further transmutation or immobilization inside specific matrices. These radioelements are present in acid solutions of fission products in the form of cations (cesium), anions (technetium, selenium) and molecules (iodine). Crown calixarenes have been successfully used for the extraction of cesium thanks to their exceptional selectivities. This work is mainly based on the use of the chelating properties of calixarenes for the extraction of anionic radioelements. Calixarenes functionalized by amino-carbon chains have been selected. The synthesis of amine calix[4]arenes and calix[6]arenes is described and their extractive and ionophoretic properties with respect to radioelements are shown using aqueous selective separation techniques like the liquid-liquid extraction and the supported liquid membrane transport. Technetium and selenium are extracted by amine calixarenes from a 10{sup -2} M aqueous solution of nitric acid. At this acidity, no selenium transport is observed, while technetium transport is efficient: the solution is quasi-totally decontaminated in 6 hours. Molecular iodine is efficiently extracted with a simple organic diluent, the 1,2-nitro-phenyl-hexyl-ether, from a strongly concentrated aqueous solution of nitric acid (HNO{sub 3} = 3 M). The transport of iodine becomes faster and more efficient when its concentration in the solution is higher. (J.S.)

  1. Low-generation dendrimers with a calixarene core and based on a chiral C2-symmetric pyrrolidine as iminosugar mimics

    Directory of Open Access Journals (Sweden)

    Marco Marradi

    2012-06-01

    Full Text Available The preparation of low-generation dendrimers based on a simple calix[4]arene scaffold by insertion of the iminosugar-analogue C2-symmetric 3,4-dihydroxypyrrolidine is described. This methodology allows a rapid incorporation of a considerable number of iminosugar-like moieties in a reduced volume and in a well-defined geometry. The inclusion of alkali-metal ions (sodium and potassium in the polar cavity defined by the acetamide moieties at the lower rim of the calixarene was demonstrated, which allows also the rigidification of the dendrimer structure and the iminosugar presentation in the clusters. The combination of the supramolecular properties of calixarenes with the advantage of a dendrimeric presentation of repetitive units opens up the possibility of generating well-defined multivalent and multifaceted systems with more complex and/or biologically relevant iminosugars.

  2. Cyclodextrin- and calixarene-based polycationic amphiphiles as gene delivery systems: A structure-activity relationship study

    OpenAIRE

    Gallego-Yerga, Laura; Lomazzi, Michela; Franceschi, Valentina; Sansone, Francesco; Ortiz-Mellet, Carmen; Donofrio, Gaetano; Canasti, Alessandro; García-Fernández, José Manuel

    2015-01-01

    Multi-head/multi-tail facial amphiphiles built on cyclodextrin (CD) and calixarene (CA) scaffolds are paradigmatic examples of monodisperse gene delivery systems. The possibility to precisely control the architectural features at the molecular level offers unprecedented opportunities for conducting structure-activity relationship studies. A major requirement for those channels is the design of a sufficiently diverse ensemble of compounds for parallel evaluation of their capabilities to conden...

  3. The role of outer-sphere surface acidity in alkene epoxidation catalyzed by calixarene-Ti(IV) complexes.

    Science.gov (United States)

    Notestein, Justin M; Solovyov, Andrew; Andrini, Leandro R; Requejo, Felix G; Katz, Alexander; Iglesia, Enrique

    2007-12-19

    Cooperativity between Brønsted acidic defect sites on oxide surfaces and Lewis acid catalyst sites consisting of grafted calixarene-Ti(IV) complexes is investigated for controlling epoxidation catalysis. Materials are synthesized that, regardless of the surface or calixarene substituent, demonstrate nearly identical UV-visible ligand-to-metal charge-transfer bands and Ti K-edge X-ray absorption near edge spectral features consistent with site-isolated, coordinatively unsaturated Ti(IV) atoms. Despite similar Ti frontier orbital energies demonstrated by these spectra, replacing a homogeneous triphenylsilanol ligand with a silanol on a SiO2 surface increases cyclohexene epoxidation rates with tert-butyl hydroperoxide 20-fold per Ti site. Supporting calixarene-Ti active sites on fully hydroxylated Al2O3 or TiO2, which possess lower average surface hydroxyl pKa than that of SiO2, reduces catalytic rates 50-fold relative to SiO2. These effects are consistent with SiO2 surfaces balancing two competing factors that control epoxidation rates-equilibrated hydroperoxide binding at Ti, disfavored by stronger surface Brønsted acidity, and rate-limiting oxygen transfer from this intermediate to alkenes, favored by strongly H-bonding intermediates. These observations also imply that Ti-OSi rather than Ti-OCalix bonds are broken upon hydroperoxide binding to Ti in kinetically relevant steps, which is verified by the lack of a calixarene upper-rim substituent effect on epoxidation rate. The pronounced sensitivity of observed epoxidation rates to the support oxide, in the absence of changes to the Ti coordination environment, provides experimental evidence for the importance of outer-sphere H-bonding interactions for the exceptional epoxidation reactivity of titanium silicalite and related catalysts.

  4. MD simulations of the binding of alcohols and diols by a calixarene in water: connections between microscopic and macroscopic properties.

    Science.gov (United States)

    Ghoufi, A; Morel, J P; Morel-Desrosiers, N; Malfreyt, P

    2005-12-15

    We report results of molecular dynamics (MD) simulations of the complexes of p-sulfonatocalix[4]arene with linear alcohols from ethanol to heptanol in water at 25 degrees C. We show that these complexes are of the inclusion type and are governed by van der Waals interactions between the calixarene cavity and the inserted alkyl chain of the alcohol. We establish a correlation between the experimental Delta(r)H degrees values and the number of atoms inserted into the calixarene cavity. We also focus on the desolvation of the host and guest to establish the importance, at the enthalpic level, of the formation of hydrogen bond bridges between the calixarene and the alcohol molecule. The fact that methanol is not complexed by p-sulfonatocalix[4]arene is explained by calculating the cost of the desolvation of the guest upon complexation. We complete this study by modeling the complexes formed with 1,4-butanediol and 1,5-pentanediol. To explain the difference between the thermodynamic properties for the binding of 1,4-butanediol and butanol, we examine the insertion rate and the solvation of each hydroxy group. We show a specific behavior of one of the two hydroxy groups at the structural and energetic levels.

  5. [The calixarene C-107 increases the affinity of the Na+,K(+)-ATPase in plasmatic membrane of smooth muscle cells to the ouabain].

    Science.gov (United States)

    Veklich, T O; Shkrabak, O A; Rodik, R V; Kal'chenko, V I; Kosterin, S O

    2011-01-01

    In the experiments carried out with the suspension of the myometrium cell plasmatic membranes treated with 0.1% digitonin solution we investigated the influence of calixarene C-107 (5,17-diamino(2-pyridyl)methylphosphono-11,23-di-tret-butyl-26,28-dihydroxy-25,27-dipropoxyca-lix[4]arene) on the Na+,K(+)-ATPase activity. It was shown that this calixarene increased the affinity of the enzyme for the sodium pump conventional inhibitor - ouabain: the magnitudes of the seeming constant of inhibition I0.5 changed from 26.9 +/- 1.3 mM to 10.9 +/- 0.6 mM. However the ouabain itself did not influence on the affinity of the Na+,K(+)-ATPase for calixarene C-107.

  6. Novel urea-linked cinchona-calixarene hybrid-type receptors for efficient chromatographic enantiomer separation of carbamate-protected cyclic amino acids.

    Science.gov (United States)

    Krawinkler, Karl Heinz; Maier, Norbert M; Sajovic, Elisabeth; Lindner, Wolfgang

    2004-10-22

    Two novel diastereomeric cinchona-calixarene hybrid-type receptors (SOs) were synthesized by inter-linking 9-amino(9-deoxy)-quinine (AQN)/9-amino(9-deoxy)-epiquinine (eAQN) and a calix[4]arene scaffold via an urea functional unit. Silica-supported chiral stationary phases (CSPs) derived from these SOs revealed, for N-protected amino acids, complementary chiral recognition profiles in terms of elution order and substrate specificity. The AQN-derived CSP showed narrow-scoped enantioselectivity for open-chained amino acids bearing pi-acidic aromatic protecting groups, preferentially binding the (S)-enantiomers. In contrast, the eAQN congener exhibited broad chiral recognition capacity for open-chained as well as cyclic amino acids, and preferential binding of the (R)-enantiomers. Exceedingly strong retention due to nonenantioselective hydrophobic analyte-calixarene interactions observed with hydro-organic mobile phases could be largely suppressed with organic mobile phases containing small amounts of acetic acid as acidic modifier. With the eAQN-calixarene hybrid-type CSP particularly high levels of enantioselectivity could be achieved for tert-butoxycarbonyl (Boc)-, benzyloxycarbonyl (Z)- and fluorenylmethoxycarbonyl (Fmoc)-protected cyclic amino acids using chloroform as mobile phase, e.g. an enantioselectivty factor alpha >5.0 for Boc-proline. Increasing amounts of acetic acid compromised enantioselectivity, indicating the crucial contributions of hydrogen bonding to chiral recognition. Comparison of the performance characteristics of the urea-linked eAQN-calixarene hybrid-type CSP with those of structurally closely related mutants provided evidence for the active involvement of the urea and calixarene units in the chiral recognition process. The urea linker motif was shown to contribute to analyte binding via multiple hydrogen bonding interactions, while the calixarene module is believed to support stereodiscrimination by enhancing the shape complementarity of the

  7. Nanolithography by scanning probes on calixarene molecular glass resist using mix-and-match lithography

    Science.gov (United States)

    Kaestner, Marcus; Hofer, Manuel; Rangelow, Ivo W.

    2013-07-01

    Going "beyond the CMOS information-processing era," taking advantage of quantum effects occurring at sub-10-nm level, requires novel device concepts and associated fabrication technologies able to produce promising features at acceptable cost levels. Herein, the challenge affecting the lithographic technologies comprises the marriage of down-scaling the device-relevant feature size towards single-nanometer resolution with a simultaneous increase of the throughput capabilities. Mix-and-match lithographic strategies are one promising path to break through this trade-off. Proof-of-concept combining electron beam lithography (EBL) with the outstanding capabilities of closed-loop electric field current-controlled scanning probe nanolithography (SPL) is demonstrated. This combination, whereby also extreme ultraviolet lithography (EUVL) is possible instead of EBL, enables more: improved patterning resolution and reproducibility in combination with excellent overlay and placement accuracy. Furthermore, the symbiosis between EBL (EUVL) and SPL expands the process window of EBL (EUVL) beyond the state of the art, allowing SPL-based pre- and post-patterning of EBL (EUVL) written features at critical dimension levels with scanning probe microscopy-based pattern overlay alignment capability. Moreover, we are able to modify the EBL (EUVL) pattern even after the development step. The ultra-high resolution mix-and-match lithography experiments are performed on the molecular glass resist calixarene using a Gaussian e-beam lithography system operating at 10 keV and a home-developed SPL setup.

  8. [Comparative study of calixarene effect on Mg2+ -dependent ATP-hydrolase enzymatic systems from smooth muscle cells of the uterus].

    Science.gov (United States)

    Labyntseva, R D; Slinchenko, N M; Veklich, T O; Rodik, R V; Cherenok, S O; Boĭko, V I; Kal'chenko, V I; Kosterin, S O

    2007-01-01

    Investigation the influence of calyx[4]arenes C-90, C-91, C-97 and C-99 (codes are indicated) on the enzymatic activity of four functionally different Mg2+ -dependent ATPases from smooth muscle of the uterus: actomyosin ATPase, transporting Ca2+, Mg2+ -ATPase, ouabain-sensible Na+, K+ -ATPase and basal Mg2+ -ATPase. It was shown that calixarenes C-90 and C-91 in concentration 100 microM act multidirectionally on the functionally different Mg2+ -dependent ATP-hydrolase enzymatic systems. These compounds activate effectively the actomyosin ATPase (Ka = 52 +/- 11 microM [Ukrainian character: see text] 8 +/- 2 microM, accordingly), at the same time calixarene C-90 inhibited effectively activity of transporting Ca2+, Mg2+ -ATPase of plasmatic membranes (I(0,5) = 34.6 +/- 6.4 microM), but influence on membrane-bound Na+, K+ -ATPase and basal Mg2+ -ATPase. Calixarene C-91 reduce effectively basal Mg2+ -ATPase activity, insignificantly activating Na+, K+ -ATPase but has no influence on transporting Ca2+, Mg2+ -ATPase activity of plasmatic membranes. Calixarenes C-97 and C-99 (100 microM), which have similar structure, have monodirectional influence on activity of three functionally different Mg2+-dependent ATPases of the myometrium: actomyosin ATPase and two ATPases, that related to the ATP-hydrolases of P-type--Ca2+, Mg2+ -ATPase and Na+, K+ -ATPase of plasmatic membranes. Basal Mg2+ -ATPase is resistant to the action of these two connections. Results of comparative experiments that were obtained by catalytic titration of calixarenes C-97 and C-99 by actomyosin ATPase (I(0,5) = 88 +/- 9 and 86 +/- 8 microM accordingly) and Na+, K+ -ATPase from plasmatic membranes (I(0,5) = 33 +/- 4 and 98 +/- 8 nM accordingly) indicate to the considerably more sensitiveness of Na+, K+ -ATP-ase to these calixarenes than ATPase of contractile proteins. Thus, it is shown that calixarenes have influence on activity of a number of important enzymes, involved in functioning of the smooth muscle

  9. Host-Guest Interactions between Calixarenes and Cp(2)NbCl(2).

    Science.gov (United States)

    Morales, Alexis; Santana, Alberto; Althoff, Gerhard; Melendez, Enrique

    2011-07-01

    The possible inclusion complexes of Cp(2)NbCl(2) into calixarenes hosts have been investigated. The existence of a true inclusion complex in the solid state was confirmed by a combination of NMR, ab-initio calculations, thermogravimetric analysis, FTIR, Raman and PXRD. Ab-initio calculations, (1)H NMR solution and solid state (13)C CP MAS NMR results demonstrated that p-sulfonic calix[6]arene does form an inclusion complex with Cp(2)NbCl(2). Raman spectroscopy showed, for the inclusion compound of p-sulfonic calix[6]arene-Cp(2)NbCl(2), a band between 500-850 cm(-1) characteristic of Nb-O vibration. This result suggests that Nb(V) may engage in coordination with the oxygen of the sulfonate group, as part of the host-guest interaction. However, it is important to mention that the niobocene dichloride (Cp(2)NbCl(2)) dissolves in water and undergoes oxidation and hydrolysis processes to yield Cp(2)NbCl(2)(OH) species. For that reason this band does not exclude that the Nb-O band belongs to Cp(2)NbCl(2)(OH). Solid State (13)C CP MAS NMR and solution (1)H NMR spectroscopies together with ab-initio results showed that Cp(2)NbCl(2) is included in the p-sulfonic calix[6]arene cavity, with both Cp rings inside the cavity. In contrast, the solution (1)H NMR results demonstrated that calix[6]arene does not form inclusion complex with Cp(2)NbCl(2) in CDCl(3) solution. Cp(2)NbCl(2) is not included in the calix[6]arene cavity, possibly due to the lack of sulfonate heads which promote Nb-O interactions and assist the inclusion of Cp(2)NbCl(2) into the cavity.

  10. Recognition of anions using urea and thiourea substituted calixarenes: A density functional theory study of non-covalent interactions

    Science.gov (United States)

    Athar, Mohd; Lone, Mohsin Y.; Jha, Prakash C.

    2018-02-01

    Designing of new calixarene receptors for the selective binding of anions is an age-old concept; even though expected outcomes from this field are at premature stage. Herein, we have performed quantum chemical calculations to provide structural basis of anion binding with urea and thiourea substituted calixarenes (1, 2, and 3). In particular, spherical halides (F-, Cl-, Br-) and linear anions (CN-, N3-, SCN-) were modelled for calculating binding energies with receptor 1, 2 and 3 followed by their marked IR vibrations; taking the available experimental information into account. We found that the thiourea substitutions have better capability to stabilize the anions. Results have suggested that the structural behaviour of macrocyclic motifs were responsible for displaying the anion binding potentials. Moreover, second order "charge transfer" interactions of n-σ∗NH and n-σ∗OH type along the H-bond axis played critical role in developing hydrogen bonds. The present work also examines the role of non-covalent interactions (NCI) and their effects on thermodynamic and chemical-reactivity descriptors.

  11. Chromatographic analysis of some drugs employed in erectile dysfunction therapy: qualitative and quantitative studies using calixarene stationary phase.

    Science.gov (United States)

    Hashem, Hisham; Ibrahim, Adel Ehab; Elhenawee, Magda

    2014-10-01

    In this study, the effect of change in chromatographic process variables on the retention behavior of four drugs employed in erectile dysfunction therapy on a calixarene stationary phase is described. Three of these drugs are known to treat erectile dysfunction, namely, sildenafil citrate, tadalafil, and apomorphine hydrochloride, and one drug that is used as opioid analgesic, tramadol hydrochloride, which is quiet widely misused to treat premature ejaculation. The results indicate the importance of considering the structure and pKa values of drugs to be separated along with mobile phase composition. A new optimized, rapid, and accurate liquid chromatography method is also established for simultaneous determination of sildenafil citrate, tadalafil, and apomorphine hydrochloride in pharmaceutical preparations and bulk powders. The chromatographic separation of the three pharmaceuticals was achieved on a calixarene column in less than 10 min using a binary mobile phase of 35% acetonitrile and 65% 50 mM sodium perchlorate pH2.5 at 1 mL/min flow rate. The method was validated for system efficiency, linearity, accuracy, precision, limits of detection and quantitation, specificity, stability, and robustness. Statistical analysis proved that the method enabled reproducible and selective quantification of all three analytes in bulk drugs and in pharmaceutical preparations. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Calixarene receptors in the selective separation of alachlor. Characterization of the separated complexes; Receptores calixarenicos en la separacion selectiva de alaclor. Caracterizacion de los complejos separados

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, M.C

    2004-07-01

    Pesticides have been necessary in the agriculture since the plagues control have been remedied thanks to them but it has also provoked pollution. Nowadays, there are several methods which help to decrease or remedy such a pollution provoked. Unfortunately, any of them work out the environmental problem totally. Therefore, alternatives have to be found. The organic and tri dimensional characteristics of these macrocycles afford them a high versatility in such a way that these hosts can interact with organic guests selectively. Alachlor is a chlorinated organic herbicide useful in the plagues control of annual grasses and many broad-leave weeds which grow in maize, peanuts and soyabean. The ability of calixarenes to host organic guests with chemical characteristics similar to pesticides let them to be good candidates to compete with others methods which are used presently to separate organic pesticides. In this direction one of the advantages of proposing the use of calixarenes is, its facility of being modified in the lower and/or upper rims, to adapt them to aqueous, organic, gaseous and aqueous-organic media. Once the characteristics of reagents informed in the literature were confirmed and complemented with others found in this work, we studied, in solution, the interaction of the calixarenes with alachlor using 1 x 10{sup -5} to 1 x 10{sup -3} M solutions in acetonitrile for calixarenes fitted with phosphinoyl pendant arms in the lower rim, B{sub n}bL{sup n}, n= 4, 6) and in chloroform for parents calixarenes (H{sub n}bL{sup n} n = 4, 6, 8). Meticulous studies monitored by UV-Vis and luminescence were carried out, and the best stoichiometry to be used in further studies resulted to be 1(host): 1(alachlor). Therefore, we chose the 1 x 10{sup -4} M concentration to find how long the host-guest should be interacting in order to guarantee the formation in solution of the calixarene-alachlor species. It was found 168 h for the alachlor-B{sub n}bL{sup n} interaction

  13. Amplification of anion sensing by disulfide functionalized ferrocene and ferrocene-calixarene receptors adsorbed onto gold surfaces.

    Science.gov (United States)

    Cormode, David P; Evans, Andrew J; Davis, Jason J; Beer, Paul D

    2010-07-28

    A disulfide functionalized bis-ferrocene urea acyclic receptor and disulfide functionalized mono- and bis-ferrocene amide and urea appended upper rim calix[4]arene receptors were prepared for the fabrication of SAM redox-active anion sensors. 1H NMR and diffusive voltammetric anion recognition investigations revealed each receptor to be capable of complexing and electrochemically sensing anions via cathodic perturbations of the respective receptor's ferrocene/ferrocenium redox couple. SAMs of a ferrocene urea receptor 3 and ferrocene urea calixarene receptor 17 exhibited significant enhanced magnitudes of cathodic response upon anion addition as compared to observed diffusive perturbations. SAMs of 17 were demonstrated to sense the perrhenate anion in aqueous solutions.

  14. Excited singlet (S1) state interactions of calixarenes with chloroalkanes: A combination of concerted and stepwise dissociative electron transfer mechanism

    Science.gov (United States)

    Mohanty, J.; Pal, H.; Nayak, S. K.; Chattopadhyay, S.; Sapre, A. V.

    2002-12-01

    Both steady-state and time-resolved studies in acetonitrile (ACN) solutions show that the excited singlet (S1) states of calixarenes (CX) undergo quenching by chloroalkanes (CA). It has been revealed by characterizing the Cl ions in the photolyzed CX-CA systems in ACN solutions that the quenching occurs due to dissociative electron transfer (DET) mechanism, whereby a C-Cl bond of the CAs undergoes dissociation on acceptance of an electron from excited CX. The bimolecular quenching constants (kq) in the present systems were correlated with the free energy changes for the concerted DET reactions based on a suitable DET theory. Such a correlation results in the recovery of an intramolecular reorganization energy, which is substantially lower to account for the C-Cl bond dissociation energy of the CAs. Comparing present results with those of an another donor-acceptor system (e.g., biphenyldiol-CA systems) where a concerted DET mechanism is applicable, it is inferred that in CX-CA systems both concerted and stepwise DET mechanisms operate simultaneously. It is proposed that the interaction of excited CXs with encaged CAs follows the stepwise mechanism whereas that with the out of cage CAs follows the concerted mechanism.

  15. Simulation of cesium nitrate extraction by a calixarene. Application to supported liquid membranes transport; Modelisation de l`extraction du nitrate de cesium par un calixarene. Application a la modelisation du transport a travers des membranes liquides supportees

    Energy Technology Data Exchange (ETDEWEB)

    Sorel, C.

    1996-12-12

    This work fits into the general pattern of the CEA studies on the decontamination of liquid effluents containing long-lived radioactive isotopes. Some calixarenes have proved to be very effective to selectively extract the cesium of aqueous solutions whose composition simulates those of the effluents to be reprocessed. On account of the difficulty of the studied extraction mechanisms, a physical and chemical simulation has been necessary. The system takes into account: 1)a concentrated nitric acid aqueous phase and/or sodium nitrate 2)an organic phase constituted by the diluent 1,2-nitro-phenyl-octyl-ether and 1,3-diisopropoxy-calix(4)arene-couronne-6. The use of concentrated aqueous solutions requires to take into account variations to ideality by the mean of activity coefficients reckoning. The different theories on the reckoning of variations to ideality in aqueous or organic phases are described in the first part. The determination of cesium and sodium nitrates activity coefficients in very concentrated matrices has required an important theoretical and experimental study which is given in the second part. The aim of this study was indeed to complete the thermodynamic data of cesium and sodium nitrates aqueous solutions. The computerized tools required for the modeling are reviewed. The stoichiometry of the extracted species in the organic phase has been determined in the third part. The supported membrane technique is an original method of separation by liquid-liquid extraction. A membrane transport model has been developed and is given in the last part of this work. (O.M.). 128 refs.

  16. Alkaline-Side Extraction of Cesium from Savannah River Tank Waste Using a Calixarene-Crown Ether Extractant

    Energy Technology Data Exchange (ETDEWEB)

    Bonnesen, P.V.; Delmau, L.H.; Haverlock, T.J.; Moyer, B.A.

    1998-12-01

    Results are presented supporting the viability of the alkaline-side CSEX process as a potential replacement for the In-Tank Precipitation process for removal of cesium from aqueous high-level waste (HLW) at the Savannah River Site (SRS). Under funding from the USDOE Efficient Separations and Crosscutting program, a flowsheet was suggested in early June of 1998, and in the following four months, this flowsheet underwent extensive testing, both in batch tests at ORNL and ANL and in two centrifugal-contactor tests at ANL. To carry out these tests, the initial ESP funding was augmented by direct funds from Westinghouse Savannah River Corporation. The flowsheet employed a solvent containing a calixarene-crown hybrid compound called BoBCalixC6 that was invented at ORNL and can now be obtained commercially for government use from IBC Advanced Technologies. This special extractant is so powerful and selective that it can be used at only 0.01 M, compensating for its expense, but a modifier is required for use in an aliphatic diluent, primarily to increase the cesium distribution ratio D{sub Cs} in extraction. The modifier selected is a relatively economical fluorinated alcohol called Cs3, invented at ORNL and so far available. only from ORNL. For the flowsheet, the modifier is used at 0.2 M in the branched aliphatic kerosene Isopar{reg_sign} L. Testing at ORNL and ANL involved simulants of the SRS HLW. After extraction of the Cs from the waste simulant, the solvent is scrubbed with 0.05 M HNO{sub 3} and stripped with a solution comprised of 0.0005 M HNO{sub 3} and 0.0001 M CsNO{sub 3}. The selection of these conditions is justified in this report, both on the basis of experimental data and underlying theory.

  17. Calixarenes in a membrane environment: a monolayer study on the miscibility of three p-tert-butylcalix[4]arene beta-lactam derivatives with 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine.

    Science.gov (United States)

    Korchowiec, Beata; Ben Salem, Adel; Corvis, Yohann; de Vains, Jean-Bernard Regnouf; Korchowiec, Jacek; Rogalska, Ewa

    2007-11-22

    Literature data indicate that some calixarene derivatives with antimicrobial activities may be useful as drugs; one of the aspects of the biological activity of different classes of antibiotics concerns interactions with lipid membranes. Here, the possibility of incorporation and/or translocation of three amphiphilic p-tert-butylcalix[4]arene derivatives across membranes was studied using lipid monolayers. The derivatives used have 6-aminopenicillanic acid or benzylpenicillin moieties grafted in alternate positions at the calixarene lower rim; 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), a model bacterial membrane lipid, was used to prepare the monolayers. The miscibility of calixarene-antibiotic conjugates with lipid films was studied using surface pressure and surface potential measurements, as well as Brewster angle microscopy. The results obtained show that the miscibility is significantly different for the 6-aminopenicillanic acid and the two benzylpenicillin derivatives. Molecular modeling allowed the assessment of the lowest energy conformations of the calixarene derivatives and gave more insight into the interactions with the DMPE films.

  18. Role of electronic polarization on the liquid phase affinity of calixarene crown-ethers towards alkali cations: a QM/MM molecular dynamics simulation

    Science.gov (United States)

    Golebiowski, Jérôme; Lamare, Véronique; Martins-Costa, Marilia T. C.; Millot, Claude; Ruiz-López, Manuel F.

    2001-10-01

    We report molecular dynamics simulations of calixarene-crown-ether complexes with alkali cations in water using hybrid quantum mechanics/molecular mechanics (QM/MM) potentials. The approach allows us, for the first time in this kind of systems, to make a detailed discussion on the role of electronic polarization. Such an effect had been omitted in previous studies of calixarene-alkali cation complexes, although it is known to be important in many host-guest systems. The macrocycle, calix[4]arene-bis-crown6 (BC6), is treated at the semiempirical AM1 level whereas solvent water molecules are treated using the TIP3P model. The alkali metal cations (Na + and Cs +) are described as classical point charges with a set of Lennard-Jones parameters developed in this work. The interaction energy is analysed in terms of strain, electrostatic, polarization and van der Waals contributions. The polarization component is shown to be substantial and may represent 20% of the total electrostatic energy. We show that instantaneous fluctuation of the net atomic charge on O atoms and aromatic rings are quite large. The structural results predicted by the AM1/TIP3P model are shown to agree reasonably well with X-ray data. Comparison with previous MM simulations using effective pairwise additive potentials is made. Some differences found in the case of the BC6/Na + system, namely for the solvation number, are discussed.

  19. Removal of cesium from nuclear liquid waste using hybrid organic-inorganic membranes grafted by immobilized calixarenes; Synthese et caracterisation de membranes hybrides organo-minerales contenant des calixarenes. Application au traitement des effluents radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Duhart, A

    1998-07-01

    The aim of the Actinex program is to reduce massively the noxiousness of the vitrified wastes mainly due to actinides and other long-lived fission products such as {sup 129}I, {sup 99}Tc or {sup 135}Cs. Specific treatment means applicable to the industrial processes of spent fuel reprocessing have to be defined. The selective extraction of these radioelements for their transmutation or packaging in specific matrices is one of the research theme of this program. Different studies allowing the extraction of radioelements such as cesium, americium and plutonium by preferential diffusional transport through a supported liquid membrane of complexes (formed between a selective transport compound and the radioelements) are at the present time carried out in the ETPL (Effluents Treatment Processes Laboratory). Calix-4-arenes mono/bis-crown-6 are used as selective transport compounds. Meanwhile the possible losses of the selective transport compound by dissolution in the aqueous phases have oriented our researches towards a solid material in which the selective transport compound is chemically bound or trapped in the matrix. The transport compound is a calixarene, dissymmetrical and double grafted. It has been specifically synthesized for this study. It allows both to complex the cesium and to chemically bind a hetero-poly-siloxane. These monomers have poly-condensable groups which lead by sol-gel process to the formation of a three-dimensional bonds lattice. The matrix, thus obtained, can be supported either on a mineral material or on a porous organic material. Pre-polymers and the deposited layers have been characterized and correlations between the materials preparation and their properties, applied to cesium extraction, have been established. Experiments of cesium transfer through the solid membrane containing between 2 to 40% of selective transport compound, located between 2 compartments containing upstream, an acidic solution with strong salinity doped with Cs 137

  20. Cyclodextrin- and calixarene-based polycationic amphiphiles as gene delivery systems: a structure-activity relationship study.

    Science.gov (United States)

    Gallego-Yerga, Laura; Lomazzi, Michela; Franceschi, Valentina; Sansone, Francesco; Ortiz Mellet, Carmen; Donofrio, Gaetano; Casnati, Alessandro; García Fernández, José M

    2015-02-14

    Multi-head/multi-tail facial amphiphiles built on cyclodextrin (CD) and calixarene (CA) scaffolds are paradigmatic examples of monodisperse gene delivery systems. The possibility to precisely control the architectural features at the molecular level offers unprecedented opportunities for conducting structure-activity relationship studies. A major requirement for those channels is the design of a sufficiently diverse ensemble of compounds for parallel evaluation of their capabilities to condense DNA into transfection nanoparticles where the gene material is protected from the environment. Here we have undertaken the preparation of an oriented library of β-cyclodextrin (βCD) and calix[4]arene (CA4) vectors with facial amphiphilic character designed to ascertain the effect of the cationic head nature (aminothiourea-, arginine- or guanidine-type groups) and the macrocyclic platform on the abilities to complex plasmid DNA (pDNA) and in the efficiency of the resulting nanocomplexes to transfect cells in vitro. The hydrophobic domain, formed by hexanoyl or hexyl chains, remains constant in each series, matching the overall structure found to be optimal in previous studies. DLS, TEM and AFM data support that all the compounds self-assemble in the presence of pDNA through a process that involves initially electrostatic interactions followed by formation of βCD or CA4 bilayers between the oligonucleotide filaments. Spherical transfectious nanoparticles that are monomolecular in DNA are thus obtained. Evaluation in epithelial COS-7 and human rhabdomyosarcoma RD-4 cells evidenced the importance of having primary amino groups in the vector to warrant high levels of transfection, probably because of their buffering capacity. The results indicate that the optimal cationic head depends on the macrocyclic core, aminothiourea groups being preferred in the βCD series and arginine groups in the CA4 series. Whereas the transfection efficiency relationships remain essentially

  1. [Changes in polarization of myometrial cells plasma and internal mitochondrial membranes under calixarenes action as inhibitors of plasma membrane Na+, K+-ATPase].

    Science.gov (United States)

    Danylovych, H V; Danylovych, Iu V; Kolomiiets', O V; Kosterin, S O; Rodik, R V; Cherenok, S O; Kal'chenko, V I; Chunikhin, O Iu; Horchev, V F; Karakhim, S O

    2012-01-01

    The influence of supramolecular macrocyclic compounds--calix[4]arenes C-97, C-99, C-107, which are ouabainomymetic high affinity inhibitors of Na+, K(+)-ATPase, on the polarization level of plasmic and mitochondrial membranes of rat uterine smooth muscle cells was investigated. The influence of these compounds on the myocytes characteristic size was studied. By using a confocal microscopy and specific for mitochondrial MitoTracker Orange CM-H2TMRos dye it was proved that the potential-sensitive fluorescent probe DiOC6(3) interacts with mitochondria. Artificial potential collapse of plasmic membrane in this case was modeled by myocytes preincubation with ouabain (1 mM). Further experiments performed using the method of flow cytometry with DiOC6(3) have shown that the compounds C-97, C-99 and C-107 at concentration 50-100 nM caused depolarization of the plasma membrane (at the level of 30% relative to control values) in conditions of artificial collapse of mitochondrial potential by myocytes preincubation in the presence of 5 mM of sodium azide. Under artificial sarcolemma depolarization by ouabain, calixarenes C-97, C-99 and C-107 at 100 nM concentrations caused a transient increase of mitochondrial membrane potential, that is 40% of the control level and lasted about 5 minutes. Calixarenes C-99 and C-107 caused a significant increase in fluorescence of myocytes in these conditions, which was confirmed by confocal microscopy too. It was proved by photon correlation spectroscopy method that the C-99 and C-107 caused an increase of characteristic size of myocytes.

  2. On-cartridge derivatisation using a calixarene solid-phase extraction sorbent for facile, sensitive and fast determination of formaldehyde in beer.

    Science.gov (United States)

    Deng, Zhifen; Hu, Kai; Zhang, Yongming; Zhao, Wenjie; Wang, Fei; Guo, Ling; Zhang, Wenfen; He, Juan; Huang, Yanjie; Zhang, Shusheng

    2016-11-15

    This work demonstrates the successful application of an on-cartridge derivatisation procedure for facile, fast and sensitive determination of formaldehyde in beer by HPLC-UV. The derivatisation and solid-phase extraction (SPE) were integrated into a novel calixarene SPE sorbent: tetraazacalix[2]arene[2]triazine bonded silica gel. Specifically, 2,4-dinitrophenylhydrazine was adsorbed onto the sorbent in advance, based on the charge-transfer interaction between the macrocyclic molecule and nitrobenzenes. The method was optimised and validated: under the optimal conditions of derivatisation, SPE and HPLC separation, good linearity was obtained in the range of 0.080-3.2μgmL(-1) with a correlation coefficient of 0.9939, the limit of detection was 3.0ngmL(-1) (S/N=3), the limit of quantification was 10ngmL(-1) (S/N=10), and the recovery level using this method was desirable at 75-84%. The developed method was successfully applied to determine formaldehyde content in real beer samples; the results were in the range of 0.11-1.1μgmL(-1). Copyright © 2016. Published by Elsevier Ltd.

  3. The Nature of Aqueous Solutions of a Cationic Calix[4]arene: A Comparative Study of Dye–Calixarene and Dye–Surfactant Interactions

    Directory of Open Access Journals (Sweden)

    V. I. Kalchenko

    2006-08-01

    Full Text Available Among different types of calixarenes, the water–soluble ones are of especial interestbecause of their possible applications in biochemical research. In order to elucidate the natureof aqueous solutions of a cationic amphiphilic calixarene, substituted tetrapropoxycalix[4]arene bearing hydrophilic choline groups at the upper rim, we studied vis–spectroscopically the influence of the above system on the acid–base behavior of threeindicator dyes, namely, 2,4-dinitrophenol, bromophenol blue, and N,N/-dioctadecylrhodamine,at constant ionic strength of 0.05 M, maintained with NaCl addition. Simultaneously,‘apparent’ ionization constants, Kaa , of the same dyes were determined in the presence ofcommon cationic surfactant micelles. Within the concentration range from 1.0×10–5 to 0.01 M,the aforementioned water–soluble calixarene displays effects similar to those of micelles ofcetyltrimethylammonium bromide (or chloride. The shifts of the absorption and emissionbands in the visible region, as well as the alterations of the Kaa values against the ‘aqueous’ones appeared to be very similar in aqueous solutions of both calix[4]arene and cationicsurfactant. A conclusion can be made about aggregation (or association, i.e., micelleformation of the cationic calix[4]arene under study.

  4. Thermodynamic modelling of the extraction of nitrates of lanthanides by CMPO and by CMPO-like calixarene in concentrated nitric acid medium. Application in the optimization of the separation of lanthanides and actinides/lanthanides; Modelisation thermodynamique de l'extraction de nitrates de lanthanides par le CMPO et par un calixarene-CMPO en milieu acide nitrique concentre. Application a l'optimisation de la separation des lanthanides et des actinides/lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Belair, S

    2003-07-01

    The separation minor actinides / lanthanides in nitric acid medium is as one of problems of separative chemistry the most delicate within the framework of the processes allowing the recovery of long life radioelements present in the solutions of fission products. Previous studies showed that CMPO-substituted calix[4]arenes presents a better affinity for actinides than for lanthanides. To optimize the operating conditions of separation and to take into account the degree of non-ideality for the concentrated nitric solutions, we adopted a thermodynamic approach. The methodology taken to determine the number and the stoichiometry of the complexes formed in organic phase base on MIKULIN-SERGIEVSKII's model used through a software of data processing of experimental extraction isotherms. These tools are exploited at first on an extraction system engaging the CMPO, extractant reagent of actinides and lanthanides in concentrated nitric medium. The modelling of the system Ln(NO{sub 3}){sub 3}-HNO{sub 3}-H{sub 2}O/CMPO comes to confirm the results of several studies. At the same time, they allow to establish working hypotheses aiming at limiting the investigations of our researches towards the most stable complexes formed between lanthanides and CMPO-like calixarene to which the same method is then applied. An analytical expression of the selectivity of separation by the calixarene is established to determine the parameters and physico-chemical variables on which it depends. So, the ratio of the constants of extraction and the value of the activity of water of the system fixes the selectivity of separation of 2 elements. The exploitation of this relation allows to preview the influence of a variation of the concentration of nitric acid. Experiments of extraction confirm these forecasts and inform about the affinity of the calixarene with respect to lanthanides elements and to the americium. (author)

  5. Modeling a calixarene-crown-6 and its alkali complexes by means of a hybrid quantum mechanical/molecular mechanical method; Modelisation d'un calixarene-couronne-6 et de ses complexes alcalins par une methode hybride mecanique quantique/ mecanique moleculaire

    Energy Technology Data Exchange (ETDEWEB)

    Lamare, V.; Golebiowski, J. [CEA Cadarache, Dept. d' Entreposage et de Stockage des Dechets (DCC/DESD/SEP), 13 - Saint-Paul-lez-Durance (France); Ruiz-Lopez, M.F.; Martins-Costa, M.; Millot, C. [Universite Henri Poincare - Nancy I (UMR CNRS-UHP 7565), 54 - Nancy (France)

    2000-07-01

    Calixarene-crown-6s in 1,3-alternate conformation are compounds currently investigated for their ability to selectively extract traces of cesium from acidic or strong salinity aqueous solutions. Studies based on molecular modeling were undertaken on these systems to understand their behavior regarding cesium and other alkali cations, in particular sodium. In this work, a recently developed molecular modeling approach was used to investigate calixarene BC6 and its alkali complexes. The whole calixarene ligand is treated by the semiempirical AM1 quantum method (QM) whereas the cation and solvent are treated by a conventional force field (MM). The total energy of the system is the sum of the QM and MM sub-system contributions plus the QM/MM interaction energy. The latter includes the electrostatic interaction between QM charges (nuclei + electrons) and MM sites, and the non-electrostatic QM/MM van der Weals term, usually expressed by a Lennard-Jones potential. In the QM/MM method, van der Waals interactions between the QM and MM sub-systems are described by empirical Lennard-Jones parameters which must be adapted to the hybrid potential considered. Parameters on oxygen atoms were optimized. For the cations, two sets of Parameters were tested: Aqvist empirical parameters, derived to represent cation/water interactions in classical dynamics (set 2), and a new set of parameters which we calculated from dispersion coefficients available in the literature (set 1). The latter gave better results for the interactions with the crown. In the sodium complex, the cation interacts with only four oxygen atoms of the crown, whereas in the complex with cesium, the interaction involves six oxygen atoms. Distortion of the BC6 is therefore less with sodium and favors the corresponding complex by 4 kcal/mol. The cation/BC6 van der Waals energy is very weak for the two complexes. Hence the interaction between the cation and BC6 is primarily electrostatic. The BC6 polarization energy due

  6. Catalytic applications of keto-stabilised phosphorus ylides based on a macrocyclic scaffold: calixarenes with one or two pendant Ni(P,O)-subunits as ethylene oligomerisation and polymerisation catalysts.

    Science.gov (United States)

    Kuhn, Pierre; Sémeril, David; Jeunesse, Catherine; Matt, Dominique; Lutz, Pierre J; Louis, Rémy; Neuburger, Markus

    2006-08-14

    Four calix[4]arenes containing either one or two ylidic -C(O)CH=PPh3 moieties anchored at p-phenolic carbon atoms were prepared starting from cone-25,27-dipropoxycalix[4]arene (1): 1,3-alternate-5,17-bis(2-triphenylphosphoranylideneacetyl)-25,26,27,28-tetrapropoxycalix[4]arene (12), 1,3-alternate-5-(2-triphenylphosphoranylideneacetyl)-25,26,27,28-tetrapropoxycalix[4]arene (13), cone-5-(2-triphenylphosphoranylideneacetyl)-25,27-dihydroxy-26,28-dipropoxycalix[4]arene (14), cone-5,17-bis(2-triphenylphosphoranylideneacetyl)-25,27-dihydroxy-26,28-dipropoxycalix[4]arene (15). All the ylides were shown to be suitable for the preparation of SHOP-type complexes, i.e. of molecules containing [NiPh{Ph2PCH=C(O)R}(PPh3)] subunits (R = calixarene fragment). The monometallic complexes, namely those obtained from the monophosphorus ylides 13 and 14, proved to be efficient ethylene oligomerisation or polymerisation catalysts. At 80 degrees C, they displayed significantly better activities than the prototype [NiPh{Ph(2)PCH=C(O)Ph}(PPh3)], hence reflecting the beneficial role of the bulky calixarene substituent. The systems derived from the two ylides 12 and 15, both containing two convergent ylidic moieties, resulted in lower activities, the proximity of the two catalytic centres facilitating an intramolecular deactivation pathway during the period of catalyst activation. For the first time, the solid-state structure of a complex containing two "NiPh(P,O)(PPh3)" units as well as that of a SHOP-type complex having two linked phosphorus units were determined.

  7. Structural study of the uranyl and rare earth complexation functionalized by the CMPO; Etude structurale de la complexation de l'uranyle et des ions lanthanides par des calixarenes fonctionnalises par le CMPO

    Energy Technology Data Exchange (ETDEWEB)

    Cherfa, S

    1998-12-10

    In view of reducing the volume of nuclear waste solutions, a possible way is to extract simultaneously actinide and lanthanide ions prior to their ulterior separation.. Historically, the two extractant families used for nuclear waste reprocessing are the phosphine oxides and the CMPO (Carbamoyl Methyl Phosphine Oxide). For a better understanding of the complexes formed during extraction, we undertook structural studies of the complexes formed between uranyl and lanthanide (III) ions and the two classes of ligands cited above. These studies have been performed by X-ray diffraction on single crystals. Recently, a new type of extractants of lanthanide (III) and actinide (III) ions has been developed. When the Organic macrocycle called calixarene (an oligomeric compound resulting from the poly-condensation of phenolic units) is functionalized by a CMPO ligand, the extracting power, in terms of yield and selectivity towards lightest lanthanides, is greatly enhanced compared to the one measured for the single CMPO. Our X-ray diffraction studies allowed us to characterise, in terms of stoichiometry and monodentate or bidentate coordination mode of the CMPO functions, the complexes of calix[4]arene-CMPO (with four phenolic units) with lanthanide nitrates and uranyl. These different steps of characterisation enabled us to determine the correlation between the structures of the complexes and both selectivity and exacerbation of the extracting power measured in the liquid phase. (author)

  8. Calixarenes: Versatile molecules as molecular sensors for ion ...

    Indian Academy of Sciences (India)

    Most of the ionophores reported in this review have been characterized crystallographically, however no structural information (except one case) are incorporated in this article, as it will occupy space without significant enhancement of chemistry part. Different factors such as size of the ionophore cavity, size of metal ion, ...

  9. Review on calixarene-type macrocycles and metal extraction data

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, R. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1995-12-01

    This paper gives an overview on the current state of solvent extraction studies with derivatized [1.n]-metacyclophanes and related compounds. 122 References from the last ten years are discussed and data on extractability, extraction equilibria, and complex formation are presented in graphical form. (author) 122 refs.

  10. Potentiometric polymeric membrane electrodes for mercury detection using calixarene ionophores.

    Science.gov (United States)

    Tyagi, Sonika; Agarwal, Himanshu; Ikram, Saiqa

    2010-01-01

    It is here established that potentiometric polymeric membrane electrodes based on electrically neutral ionophores are a useful analytical tool for the detection of heavy metal ions from environmental and industrial waste water. PVC based membrane containing p-tert-butyl-calix[4]arenethioether derivative as active material along with sodiumtetraphenylborate (NaTPB) as solvent mediator and dibutylphthalate as a plasticizer in the ratio 45:9:460:310 (w/w%) (I:NaTPB:DBP:PVC) exhibits good properties with a Nernstian response of 29.50+/-1.0 mV per decade of activity and a working concentration range of 7.2 x 10(-8)-1.0 x 10(-1) M. The electrode gave more stable potential readings when used around pH 2.5-6.8 and exhibits fast response time of 14 s. The sensors were found to work satisfactorily in partially non-aqueous media up to 40% (v/v) content of acetone, methanol or ethanol and could be used over a period of 7-9 months. Excellent selectivity for Hg(2+) ions is indicated by match potential method and fixed interference method. The sensors could be used successfully in the estimation of mercury in different sample.

  11. Extractant composition including crown ether and calixarene extractants

    Science.gov (United States)

    Meikrantz, David H.; Todd, Terry A.; Riddle, Catherine L.; Law, Jack D.; Peterman, Dean R.; Mincher, Bruce J.; McGrath, Christopher A.; Baker, John D.

    2009-04-28

    An extractant composition comprising a mixed extractant solvent consisting of calix[4] arene-bis-(tert-octylbenzo)-crown-6 ("BOBCalixC6"), 4',4',(5')-di-(t-butyldicyclo-hexano)-18-crown-6 ("DtBu18C6"), and at least one modifier dissolved in a diluent. The DtBu18C6 may be present at from approximately 0.01M to approximately 0.4M, such as at from approximately 0.086 M to approximately 0.108 M. The modifier may be 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol ("Cs-7SB") and may be present at from approximately 0.01M to approximately 0.8M. In one embodiment, the mixed extractant solvent includes approximately 0.15M DtBu18C6, approximately 0.007M BOBCalixC6, and approximately 0.75M Cs-7SB modifier dissolved in an isoparaffinic hydrocarbon diluent. The extractant composition further comprises an aqueous phase. The mixed extractant solvent may be used to remove cesium and strontium from the aqueous phase.

  12. Calixarenes: Versatile molecules as molecular sensors for ion ...

    Indian Academy of Sciences (India)

    -CDCl3 (3:1) at room temperature. whereas ionophore of same ring size as 4a and with tert-butyl at upper rim (4c) exhibits selectivity towards only Na. + and ionophore with three tosyl substituents at the lower rim (4d) exhibited no complexation ...

  13. Development of strategies for the highly selective functionalization of calixarenes and study of host–guest properties of calixarene-based molecular boxes

    OpenAIRE

    Lavendomme, Roy

    2016-01-01

    Ce travail s’inscrit dans le cadre de l’étude de plateformes polyphénoliques et, plus spécifiquement, des calixarènes. Des macrocycles oligomériques tels que les calixarènes, cyclodextrines, cyclotrivératrylènes, pillararènes, etc. sont fortement utilisés dans de nombreuses applications telles que la reconnaissance moléculaire, la détection, la séparation, le greffage sur surface, etc. Le développement de telles applications requiert toutefois modification sélective de ces macrocycles pour le...

  14. Selective extraction of actinides by calixarenes: application to bioassay analysis; Extraction selective des actinides par les calixarenes: application a l'analyse radiotoxicologique

    Energy Technology Data Exchange (ETDEWEB)

    Boulet, B

    2006-01-15

    In the context of nuclear workers monitoring, the aim of this PhD was to selectively isolate U, Pu, and Am from urine to propose a new analytical procedure to the Medical and Biology Analysis Laboratories. The 1,3,5-OCH{sub 3}-2,4,6-OCH{sub 2}CONHOH-p-tert-butyl-calix[6]arene molecule has been selected as a promising extractant for U, Pu, and Am. Its physico-chemical properties and its affinity for UO{sub 2}{sup 2+} have been studied through two approaches, one theoretical (molecular modelling at DFT level), and one experimental. The extractions of the three actinides by the hydroxamic calix[6]arene were quantitative in liquid-liquid and solid-liquid systems. Their separation has also been shown possible and efficient. After optimization, the proposed procedure should allow the laboratories to carry out the chemical treatment of urine, before the measurement, in one day instead of the three days needed nowadays. (author)

  15. Highly Efficient Chirality Transfer from Diamines Encapsulated within a Self-Assembled Calixarene-Salen Host.

    Science.gov (United States)

    Martínez-Rodríguez, Luis; Bandeira, Nuno A G; Bo, Carles; Kleij, Arjan W

    2015-05-04

    A calix[4]arene host equipped with two bis-[Zn(salphen)] complexes self-assembles into a capsular complex in the presence of a chiral diamine guest with an unexpected 2:1 ratio between the host and the guest. Effective chirality transfer from the diamine to the calix-salen hybrid host is observed by circular dichroism (CD) spectroscopy, and a high stability constant K2,1 of 1.59×10(11)  M(-2) for the assembled host-guest ensemble has been determined with a substantial cooperativity factor α of 6.4. Density functional calculations are used to investigate the origin of the stability of the host-guest system and the experimental CD spectrum compared with those calculated for both possible diastereoisomers showing that the M,M isomer is the one that is preferentially formed. The current system holds promise for the chirality determination of diamines, as evidenced by the investigated substrate scope and the linear relationship between the ee of the diamine and the amplitude of the observed Cotton effects. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Synthesis and Characterization of Calixarene Tetraethers: An Exercise in Supramolecular Chemistry for the Undergraduate Organic Laboratory

    Science.gov (United States)

    Debbert, Stefan L.; Hoh, Bradley D.; Dulak, David J.

    2016-01-01

    In this experiment for an introductory undergraduate organic chemistry lab, students tetraalkylate tertbutylcalix[4]arene, a bowl-shaped macrocyclic oligophenol, and examine the supramolecular chemistry of the tetraether product by proton nuclear magnetic resonance (NMR) spectroscopy. Complexation with a sodium ion reduces the conformational…

  17. Vesicle-to-micelle transition in aqueous solutions of amphiphilic calixarene derivatives

    Science.gov (United States)

    Micali, Norberto; Villari, Valentina; Consoli, Grazia M. L.; Cunsolo, Francesca; Geraci, Corrada

    2006-05-01

    Structure and conformation of spontaneous self-assembled calix[8]arenes derivatives are studied by means of static and dynamic light scattering and electrophoretic mobility. These amphiphilic molecules are in the aggregated form in aqueous solution, in a wide range of pH ; they take a vesicle structure in neutral and basic pH environment, but, in relatively strong acidic conditions (below pH=4.5 ), a transition from vesicle to micelle occurs. The structural change is driven by the surface charge density. At neutral pH calix[8]arenes take a negative surface charge, which prevents coagulation and ensures stability; at acidic pH the surface charge tend to become positive because of the protonation of the hydrophilic head. These pH -responsive aggregates, able to release an encapsulated hydrophilic guest, are promising systems for application as nanocarriers.

  18. Building a novel vitronectin assay by immobilization of integrin on calixarene monolayer.

    Science.gov (United States)

    Chen, Hongxia; Lee, Minsu; Lee, Jaebeom; An, Won Gun; Choi, Heung-Jin; Kim, Sung-Hoon; Koh, Kwangnak

    2008-03-15

    Membrane proteins possess significant hydrophobic domains and are likely to deplete their native activity immobilized on the solid surface relative to those occurring in a membrane environment. To investigate an efficient immobilization method, calix[4]crown-ether monolayer as an artificial protein linker system was constructed on the gold surface and characterized by Fourier transform infrared reflection absorption spectroscopy (FTIR-RAS), atomic force microscopy (AFM) and cyclic voltammetry (CV). Integrin alpha(v)beta3 was functionally immobilized onto the monolayer and the integrin-vitronectin interaction was investigated by surface plasmon resonance (SPR). It was found that calix[4]crown-ether was assembled as a monolayer on the gold surface. Orientation and accessibility of integrin alpha(v)beta3 was assessed by sensitive binding of its natural ligand, vitronectin at pg mL(-1) level. Moreover, surface coverage of integrin layer and thickness calculated through SPR curve simulation verified that integrin layer was a monolayer in activated form. In combination with the SPR method, this calix[4]crown monolayer provided a reliable and simple experimental platform for the investigation of isolated membrane proteins under experimental conditions resembling those of their native properties.

  19. Modular assembly of metal-organic super-containers incorporating calixarenes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhenqiang; Dai, Feng-Rong

    2018-01-16

    A new strategy to design container molecules is presented. Sulfonylcalix[4]arenes, which are synthetic macrocyclic containers, are used as building blocks that are combined with various metal ions and tricarboxylate ligands to construct metal-organic `super-containers` (MOSCs). These MOSCs possess both endo and exo cavities and thus mimic the structure of viruses. The synthesis of MOSCs is highly modular, robust, and predictable.

  20. Binding of calixarene-based Langmuir monolayers to mercury chloride is dependent on the amphiphile structure

    Energy Technology Data Exchange (ETDEWEB)

    Tulli, Ludovico G.; Wang, Wenjie; Rullaud, Vanessa; Lindemann, William R.; Kuzmenko, Ivan; Vaknin, David; Shahgaldian, Patrick

    2016-01-01

    Two amphiphilic calix[4]arenes bearing four dodecyl chains at the lower rim and two amino functions (vicinal and distal) at the para-phenolic positions have been synthesized. Surface-pressure versus molecular-area isotherms reveal that Langmuir monolayers of the two regioisomers show considerably distinct self-assembly behaviors at the air–water interface. Compression isotherms, Brewster angle microscopy and synchrotron-based X-ray near-total-reflection fluorescence, X-ray reflectivity and grazing incidence X-ray diffraction reveal that the monolayers of the two diamino calix[4]arene derivatives and those of their structural analogues bearing four amino moieties in para positions exhibit significant differences in their binding properties towards HgCl2 despite the structural and functional similarity among the macrocycles.

  1. Interfacial Binding of Divalent Cations to Calixarene-Based Langmuir Monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Tulli, Ludovico G.; Wang, Wenjie; Lindemann, William R.; Kuzmenko, Ivan; Meier, Wolfgang; Vaknin, David; Shahgaldian, Patrick

    2015-02-20

    The interactions of Langmuir monolayers produced through the self-assembly of an amphiphilic p-carboxycalix[4]arene with a series of divalent, fourth-period transition metals, at the air-water interface, were investigated. Changes in the interfacial behavior of 1 in response to the presence of CuCl2, CoCl2, MnCl2, and NiCl2 were studied by means of Langmuir compression isotherms and Brewster angle microscopy (BAM). The measurements revealed that the self-assembly properties of 1 are significantly affected by Cu2+ ions. The interactions of 1-based monolayers with Co2+ and Cu2+ ions were further investigated by means of synchrotron radiation-based X-ray reflectivity (XRR), X-ray near-total-reflection fluorescence (XNTRF), and grazing incidence X-ray diffraction (GIXD). XNTRF and XRR analyses revealed that the monolayer of 1 binds more strongly to Cu2+ than Co2+ ions. In the presence of relatively high concentrations of Cu2+ ions in the subphase (1.4 × 10-3 M), XNTRF exhibited anomalous depth profile behavior and GIXD measurements showed considerably strong diffuse scattering. Both measurements suggest the formation of Cu2+ clusters contiguous to the monolayer of 1.

  2. Interfacial binding of divalent cations to calixarene-based Langmuir monolayers.

    Science.gov (United States)

    Tulli, Ludovico G; Wang, Wenjie; Lindemann, William R; Kuzmenko, Ivan; Meier, Wolfgang; Vaknin, David; Shahgaldian, Patrick

    2015-03-03

    The interactions of Langmuir monolayers produced through the self-assembly of an amphiphilic p-carboxycalix[4]arene (1) with a series of divalent, fourth-period transition metals, at the air-water interface, were investigated. Changes in the interfacial behavior of 1 in response to the presence of CuCl2, CoCl2, MnCl2, and NiCl2 were studied by means of Langmuir compression isotherms and Brewster angle microscopy (BAM). The measurements revealed that the self-assembly properties of 1 are significantly affected by Cu(2+) ions. The interactions of 1-based monolayers with Co(2+) and Cu(2+) ions were further investigated by means of synchrotron radiation-based X-ray reflectivity (XRR), X-ray near-total-reflection fluorescence (XNTRF), and grazing incidence X-ray diffraction (GIXD). XNTRF and XRR analyses revealed that the monolayer of 1 binds more strongly to Cu(2+) than Co(2+) ions. In the presence of relatively high concentrations of Cu(2+) ions in the subphase (1.4 × 10(-3) M), XNTRF exhibited anomalous depth profile behavior and GIXD measurements showed considerably strong diffuse scattering. Both measurements suggest the formation of Cu(2+) clusters contiguous to the monolayer of 1.

  3. New Proton-Ionizable, Calixarene-Based Ligands for Selective Metal Ion Separations

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, Richard A.

    2012-06-04

    The project objective was the discovery of new ligands for performing metal ion separations. The research effort entailed the preparation of new metal ion complexing agents and polymers and their evaluation in metal ion separation processes of solvent extraction, synthetic liquid membrane transport, and sorption. Structural variations in acyclic, cyclic, and bicyclic organic ligands were used to probe their influence upon the efficiency and selectivity with which metal ion separations can be performed. A unifying feature of the ligand structures is the presence of one (or more) side arm with a pendent acidic function. When a metal ion is complexed within the central cavity of the ligand, ionization of the side arm(s) produces the requisite anion(s) for formation of an overall electroneutral complex. This markedly enhances extraction/transport efficiency for separations in which movement of aqueous phase anions of chloride, nitrate, or sulfate into an organic medium would be required. Through systematic structural variations, new ligands have been developed for efficient and selective separations of monovalent metal ions (e.g., alkali metal, silver, and thallium cations) and of divalent metal ion species (e.g., alkaline earth metal, lead, and mercury cations). Research results obtained in these fundamental investigations provide important insight for the design and development of ligands suitable for practical metal ion separation applications.

  4. High-efficiency pyrene-based blue light emitting diodes: Aggregation suppression using a calixarene 3D-scaffold

    KAUST Repository

    Chan, Khaileok

    2012-01-01

    An efficient blue light emitting diode based on solution processable pyrene-1,3-alt-calix[4]arene is demonstrated, providing a record current efficiency of 10.5 cd A -1 in a simple non-doped OLED configuration. Complete suppression of pyrene aggregation in the solid state is achieved by controlling chromophore dispersion using the 1,3-alt-calix[4]arene scaffold. © 2012 The Royal Society of Chemistry.

  5. The use of carbon nanotubes co-polymerized with calixarenes for the removal of cadmium and organic contaminants from water

    OpenAIRE

    2012-01-01

    M.Sc. The contamination of water by toxic compounds is one of the most serious environmental problems today. These toxic compounds mostly originate from industrial effluents, agriculture runoff, natural sources (e.g. heavy metals in water from rocks and soil erosion) and human waste. The contamination, which is both “organic” and “inorganic” has an impact on the environment and human health. The demand for water and the pressure to re-use this valuable resource has increased the need for i...

  6. Calixarene-mediated liquid membrane transport of choline conjugates 3: The effect of handle variation on neurotransmitter transport.

    Science.gov (United States)

    Collins, James L; Fujii, Ayu; Roshandel, Sahar; To, Cuong-Alexander; Schramm, Michael P

    2017-07-01

    Upper rim phosphonic acid functionalized calix[4]arene affects selective transport of multiple molecular payloads through a liquid membrane. The secret is in the attachment of a receptor-complementary handle to the payload. We find that the trimethylammonium ethylene group present in choline is one of several general handles for the transport of drug and drug-like species. Herein we compare the effect of handle variation against the transport of serotonin and dopamine. We find that several ionizable amine termini handles are sufficient for transport and identify two ideal candidates. Their performance is significantly enhanced in HEPES buffered solutions. This inquiry completes a series of 3 studies aimed at optimization of this strategy. In completion a new approach towards synthetic receptor mediated selective small molecule transport has emerged; future work in vesicular and cellular systems will follow. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Electroanalytical studies on cobalt(II) selective potentiometric sensor based on bridge modified calixarene in poly(vinyl chloride)

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, V.K.; Jain, A.K.; Raisoni, J.R. [Department of Chemistry, Indian Institute of Technology-Roorkee, Roorkee 247667 (India); Khayat, M. Al [Department of Chemistry, College of Arts and Sciences, University of Sharjah (United Arab Emirates); Bhargava, S.K. [School of Applied Sciences, RMIT University, Melbourne 3001 (Australia)

    2008-06-30

    A bridge modified 4-tert-butylthiacalix[4]arene (I) has been employed as electroactive material in the preparation of cobalt selective sensor. Polyvinyl chloride (PVC)-based membranes of (I) using sodium tetraphenylborate (NaTPB) as anion discriminator and bis(2-ethylhexyl) sebacate (DOS), chloronaphthalene (CN), tri-n-butylphosphate (TBP), o-nitrophenyl octyl ether (NPOE), tris(2-ethylhexyl)phosphate (TEHP) as plasticizers were prepared and investigated as cobalt selective sensors. A number of membranes of different compositions were prepared and investigated. The best performance was observed with the membrane having composition of 2:66:1.5:127 (mg) = I:NaTPB:PVC:NPOE. The potential response of this membrane is linear to Co{sup 2+} ions in the concentration range 5.3 x 10{sup -6} to 1.0 x 10{sup -1} M with near-Nernstian slope of 30.0 mV/decade of activity and a detection limit of {proportional_to}0.3 ppm. This membrane also showed lowest response time of 10 s and works satisfactorily in partially non-aqueous medium. The selectivity studies of this sensor, evaluated with fixed interference method and matched potential method, show that the sensor under consideration possesses excellent selectivity for Co{sup 2+} over a large number of mono-, bi- and trivalent cations such as Na{sup +}, K{sup +}, Ag{sup +}, Ca{sup 2+}, Mg{sup 2+}, Cu{sup 2+}, Hg{sup 2+}, Pb{sup 2+}, Li{sup +}, Ba{sup 2+}, Zn{sup 2+}, Sr{sup 2+}, Cr{sup 3+}, Ni{sup 2+}, etc. The sensor could be used as an indicator electrode in the quantification of Co{sup 2+} by potentiometric titration against EDTA as well as in determination of cobalt content in wastewater and beer samples. (author)

  8. Docetaxel-Loaded Nanoparticles Assembled from β-Cyclodextrin/Calixarene Giant Surfactants: Physicochemical Properties and Cytotoxic Effect in Prostate Cancer and Glioblastoma Cells.

    Science.gov (United States)

    Gallego-Yerga, Laura; Posadas, Inmaculada; de la Torre, Cristina; Ruiz-Almansa, Jesús; Sansone, Francesco; Ortiz Mellet, Carmen; Casnati, Alessandro; García Fernández, José M; Ceña, Valentín

    2017-01-01

    Giant amphiphiles encompassing a hydrophilic β-cyclodextrin (βCD) component and a hydrophobic calix[4]arene (CA4) module undergo self-assembly in aqueous media to afford core-shell nanospheres or nanocapsules, depending on the nanoprecipitation protocol, with high docetaxel (DTX) loading capacity. The blank and loaded nanoparticles have been fully characterized by dynamic light scattering (DLS), ζ-potential measurements and cryo-transmission electron microscopy (cryo-TEM). The data are compatible with the distribution of the drug between the nanoparticle core and the shell, where it is probably anchored by inclusion of the DTX aromatic moieties in βCD cavities. Indeed, the release kinetics profiles evidenced an initial fast release of the drug, which likely accounts for the fraction hosted on the surface, followed by a slow and sustained release rate, corresponding to diffusion of DTX in the core, which can be finely tuned by modification of the giant amphiphile chemical structure. The ability of the docetaxel-loaded nanoparticles to induce cellular death in different prostate (human LnCap and PC3) and glioblastoma (human U87 and rat C6) cells was also explored. Giant amphiphile-based DTX formulations surpassing or matching the antitumoral activity of the free DTX formulation were identified in all cases with no need to employ any organic co-solvent, thus overcoming the DTX water solubility problems. Moreover, the presence of the βCD shell at the surface of the assemblies is intended to impart stealth properties against serum proteins while permitting nanoparticle surface decoration by supramolecular approaches, paving the way for a new generation of molecularly well-defined antitumoral drug delivery systems with improved specificity and efficiency. Altogether, the results provide a proof of concept of the suitability of the approach based on βCD-CA4 giant amphiphiles to access DTX carriers with tunable properties.

  9. Comparison of Binding Affinities of Water-Soluble Calixarenes with the Organophosphorus Nerve Agent Soman (GD and Commonly-Used Nerve Agent Simulants

    Directory of Open Access Journals (Sweden)

    Jayne A. Ede

    2018-01-01

    Full Text Available The formation of inclusion complexes of the water-soluble p-sulfonatocalix[n]arenes, where n = 4 or 6, with the Chemical Warfare Agent (CWA GD, or Soman, and commonly used dialkyl methylphosphonate simulants has been studied by experimental solution NMR methods and by Molecular Mechanics (MMFF and semi-empirical (PM6 calculations. Complex formation in non-buffered and buffered solutions is driven by the hydrophobic effect, and complex stoichiometry determined as 1:1 for all host:guest pairs. Low affinity complexes (Kassoc < 100 M−1 are observed for all guests, attributed to poor host–guest complementarity and the role of buffer cation species accounts for the low affinity of the complexes. Comparison of CWA and simulant behavior adds to understanding of CWA–simulant correlations and the challenges of simulant selection.

  10. Docetaxel-Loaded Nanoparticles Assembled from β-Cyclodextrin/Calixarene Giant Surfactants: Physicochemical Properties and Cytotoxic Effect in Prostate Cancer and Glioblastoma Cells

    Directory of Open Access Journals (Sweden)

    Laura Gallego-Yerga

    2017-05-01

    Full Text Available Giant amphiphiles encompassing a hydrophilic β-cyclodextrin (βCD component and a hydrophobic calix[4]arene (CA4 module undergo self-assembly in aqueous media to afford core-shell nanospheres or nanocapsules, depending on the nanoprecipitation protocol, with high docetaxel (DTX loading capacity. The blank and loaded nanoparticles have been fully characterized by dynamic light scattering (DLS, ζ-potential measurements and cryo-transmission electron microscopy (cryo-TEM. The data are compatible with the distribution of the drug between the nanoparticle core and the shell, where it is probably anchored by inclusion of the DTX aromatic moieties in βCD cavities. Indeed, the release kinetics profiles evidenced an initial fast release of the drug, which likely accounts for the fraction hosted on the surface, followed by a slow and sustained release rate, corresponding to diffusion of DTX in the core, which can be finely tuned by modification of the giant amphiphile chemical structure. The ability of the docetaxel-loaded nanoparticles to induce cellular death in different prostate (human LnCap and PC3 and glioblastoma (human U87 and rat C6 cells was also explored. Giant amphiphile-based DTX formulations surpassing or matching the antitumoral activity of the free DTX formulation were identified in all cases with no need to employ any organic co-solvent, thus overcoming the DTX water solubility problems. Moreover, the presence of the βCD shell at the surface of the assemblies is intended to impart stealth properties against serum proteins while permitting nanoparticle surface decoration by supramolecular approaches, paving the way for a new generation of molecularly well-defined antitumoral drug delivery systems with improved specificity and efficiency. Altogether, the results provide a proof of concept of the suitability of the approach based on βCD-CA4 giant amphiphiles to access DTX carriers with tunable properties.

  11. Extractant compositions for co-extracting cesium and strontium, a method of separating cesium and strontium from an aqueous feed, and calixarene compounds

    Science.gov (United States)

    Peterman, Dean R [Idaho Falls, ID; Meikrantz, David H [Idaho Falls, ID; Law, Jack D [Pocatello, ID; Riddle, Catherine L [Idaho Falls, ID; Todd, Terry A [Firth, ID; Greenhalgh, Mitchell R [Iona, ID; Tillotson, Richard D [Moore, ID; Bartsch, Richard A [Lubbock, TX; Moyer, Bruce A [Oak Ridge, TN; Delmau, Laetitia H [Oak Ridge, TN; Bonnesen, Peter V [Knoxville, TN

    2012-04-17

    A mixed extractant solvent that includes at least one dialkyloxycalix[4]arenebenzocrown-6 compound, 4',4',(5')-di-(t-butyldicyclohexano)-18-crown-6, at least one modifier, and, optionally, a diluent. The dialkyloxycalix[4]arenebenzocrown-6 compound is 1,3-alternate-25,27-di(octyloxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(decyloxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(dodecyloxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(2-ethylhexyl-1-oxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(3,7-dimethyloctyl-1-oxy)calix[4]arenebenzocrown-6, 1,3-alternate-25,27-di(4-butyloctyl-1-oxy)calix[4]arenebenzocrown-6, or combinations thereof. The modifier is a primary alcohol. A method of separating cesium and strontium from an aqueous feed is also disclosed, as are dialkyloxycalix[4]arenebenzocrown-6 compounds and an alcohol modifier.

  12. Conformational isomerism and self-association of calixarene building blocks in non-polar solution studied by Fourier transform infrared spectrometry

    NARCIS (Netherlands)

    Lutz, Bert T.G.; Astarloa, Gonzalo; van der Maas, John H.; Janssen, R.G.; Janssen, Rob G.; Verboom, Willem; Reinhoudt, David

    1995-01-01

    In order to establish the conformational equilibrium of calix[6]arene derivatives, a series of phenolic building blocks differing in chain length (oligomers) have been studied in solution by Fourier transform infrared spectrometry (FT-IR). Different intramolecular OH ¿ X interactions have been

  13. Comparative study of 2-hydroxy propyl beta cyclodextrin and calixarene as ionophores in potentiometric ion-selective electrodes for neostigmine bromide.

    Science.gov (United States)

    El-Kosasy, Amira M; Nebsen, Marianne; Abd El-Rahman, Mohamed K; Salem, Maissa Y; El-Bardicy, Mohamed G

    2011-08-15

    Three novel neostigmine bromide (NEO) selective electrodes were investigated with 2-nitrophenyl octyl ether as a plasticiser in a polymeric matrix of polyvinyl chloride (PVC). Sensor 1 was fabricated using tetrakis(4-chlorophenyl)borate (TpClPB) as an anionic exchanger without incorporation of an ionophore. Sensor 2 used 2-hydroxy propyl β-cyclodextrin as an ionophore while sensor 3 was constructed using 4-sulfocalix-8-arene as an ionophore. Linear responses of NEO within the concentration ranges of 10(-5) to 10(-2), 10(-6) to 10(-2) and 10(-7) to 10(-2) mol L(-1) were obtained using sensors 1, 2 and 3, respectively. Nernstian slopes of 51.6 ± 0.8, 52.9 ± 0.6 and 58.6 ± 0.4 mV/decade over the pH range of 4-9 were observed. The selectivity coefficients of the developed sensors indicated excellent selectivity for NEO. The utility of 2-hydroxy propyl β-cyclodextrin and 4-sulfocalix[8]arene as ionophores had a significant influence on increasing the membrane sensitivity and selectivity of sensors 2 and 3 compared to sensor 1. The proposed sensors displayed useful analytical characteristics for the determination of NEO in bulk powder, different pharmaceutical formulations, and biological fluids (plasma and cerebrospinal fluid (CSF)) and in the presence of its degradation product (3-hydroxyphenyltrimethyl ammonium bromide) and thus could be used for stability-indicating methods. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. A comparative evaluation of the liquid-liquid extraction and pertraction efficiency of a both-side diglycolamide-functionalized calix[4]arene with analogous upper and lower-rim calixarenes for actinide separations

    NARCIS (Netherlands)

    Mohapatra, P.K.; Rout, D.R.; Iqbal, M.; Huskens, Jurriaan; Verboom, Willem

    2013-01-01

    A lower-rim (L-I), an upper-rim (L-II), and a both-side (L-III) diglycolamide-functionalized calix[4]arene were evaluated for the extraction of actinide ions such as UO22+, Pu4+, and Am3+ and fission product element ions such as Eu3+, Cs+, and Sr2+ from dilute nitric acid feed solutions. Conditions

  15. Calixarene-based extraction chromatographic separation of ¹³⁵Cs and ¹³⁷Cs in environmental and waste samples prior to sector field ICP-MS analysis.

    Science.gov (United States)

    Russell, Ben C; Warwick, Phil E; Croudace, Ian W

    2014-12-02

    Advances in the sensitivities achievable by sector field inductively coupled plasma mass spectrometry (ICP-SFMS) offer the prospect of low-level measurement of shorter and longer lived radionuclides, thus expanding options for environmental and radioactively contaminated land assessment. In ICP-SFMS, the critical requirement for accurate detection is the effective chemical separation of isobaric and polyatomic interferences prior to sample introduction. As instrumental detection limit capability improves, accurate radionuclide determination requires highly effective separation materials that combine high analyte selectivity with subsequent quantitative analyte recovery compatible with ICP-SFMS detection. Two radioactive isotopes measurable by ICP-SFMS are the high yield fission products (135)Cs and (137)Cs that have entered the environment as a result of anthropogenic nuclear activities. ICP-SFMS enables reliable measurement of (135)Cs/(137)Cs ratios, which can be used as a forensic tool in determining the source of nuclear contamination. The critical requirement for accurate detection is the effective removal of isobaric interferences from (135)Ba and (137)Ba prior to measurement. A number of exchange materials can effectively extract Cs; however, non-quantitative elution of Cs makes subsequent ICP-SFMS quantification challenging. A novel extraction chromatographic resin has been developed by dissolving calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) in octan-1-ol and loading onto an Amberchrom CG-71 prefilter resin material. Preparation of the material takes less than 1 h and, at an optimal concentration of 3 M HNO3, shows high selectivity toward Cs, which is effectively eluted in 0.05 M HNO3. The procedure developed shows high Cs selectivity and Ba decontamination from digests of complex matrixes including a saltmarsh sediment contaminated by aqueous discharges from a nuclear fuel reprocessing facility. Repeated tests show the resin can be reused up to four times. For low-level ICP-SFMS quantification, more complex sample matrixes benefit from a cation resin cleanup stage prior to using BOBCalixC6 that serves to enhance Ba decontamination and Cs recovery.

  16. Hybrid calix[4]arenes via ionic hydrogenation and transition-metal-mediated processes.

    Science.gov (United States)

    Bew, Sean P; Brimage, Rebecca A; Hiatt-Gipson, Glyn; Sharma, Sunil V; Thurston, Sean

    2009-06-18

    We report the first application of ionic hydrogenation for the synthesis of upper-rim urea- or carbamate-derived hybrid calix[4]arenes. Subsequent metal-mediated transformations using 4-iodophenylurea calixarenes afforded structurally unique 1,3-di(biaryl)-, 1,3-di(biarylalkyne)-, or 1,3-(biaryl)(biarylalkyne)-derived hybrid calixarenes.

  17. Versatile assembly of p-carboxylatocalix[4]arene-O-alkyl ethers

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Stuart; Teat, Simon J.; Dalgarno, Scott J.

    2009-07-08

    Crystallisation of lower-rim tetra-O-alkylated p-carboxylatocalix[4]arenes from pyridine results in the formation of both bi-layer and pillar type supramolecular motifs. Full alkylation at the calixarene lower rim has significant influence over the supramolecular self-assembly motif, including preclusion of pyridine guest molecules from the calixarene cavity in the solid state.

  18. Detection of the volatile organic compounds emitted from paints using optical fibre long period grating modified with the mesoporous nano-scale coating

    Science.gov (United States)

    Hromadka, Jiri; James, Stephen; Davis, Frank; Tatam, Ralph P.; Crump, Derrick; Korposh, Sergiy

    2015-09-01

    An optical fibre long period grating (LPG) modified with a mesoporous film infused with a calixarene as a functional compound was employed for the detection of a mixture of volatile organic compounds (VOCs). The sensing mechanism is based on the transduction of the refractive index change induced by the complexion of the VOCs with calixarene into a change in the form of the transmission spectrum of the LPG. An LPG, modified with a calixarene-infused coating comprising 5 cycles of silica nanoparticles/poly(allylamine hydrochloride) polycation (SiO2/PAH), was exposed to mixture of VOCs emitted from paint at conditions simulating ISO standards test (16000-10).

  19. Solvent-dependent host guest complexation of two homologous merocyanines by a water-soluble calix[8]arene: Spectroscopic analysis and structural calculations

    Science.gov (United States)

    Lodi, Andrea; Caselli, Monica; Casnati, Alessandro; Momicchioli, Fabio; Sansone, Francesco; Vanossi, Davide; Ponterini, Glauco

    2007-11-01

    The sulfonated calixarene I 8C 12 acts as a host for homologous merocyanines Mc1 and Mc2 in organic solvents, exhibiting neither selectivity towards the guest dyes nor solvent dependence of the complexation equilibria. In water, on the contrary, only the lower homologue, Mc1, is solubilized in the presence of the calixarene. A combination of UV-visible and fluorescence spectroscopic and photophysical analysis and MD structural simulation of the calixarene-dye complexes was employed to account for the observations, and suggests that a radical change in the complexation mode occurs upon moving from an organic to an aqueous environment.

  20. Volatile Organic Compounds Sensing Using Optical Fibre Long Period Grating with Mesoporous Nano-Scale Coating

    National Research Council Canada - National Science Library

    Hromadka, Jiri; Korposh, Sergiy; Partridge, Matthew; James, Stephen; Davis, Frank; Crump, Derrick; Tatam, Ralph

    2017-01-01

      A long period grating (LPG) modified with a mesoporous film infused with a calixarene as a functional compound was employed for the detection of individual volatile organic compounds (VOCs) and their mixtures...

  1. Amphiphilic Perylene-Calix[4]arene hybrids:synthesis and tunable self-assembly

    OpenAIRE

    Rodler, Fabian; Schade, Boris; Jaeger, Christof M.; Backes, Susanne; Hampel, Frank; Boettcher, Christoph; Clark, Timothy; Hirsch, Andreas

    2015-01-01

    The first highly water-soluble perylene–calix[4]arene hybrid with the calixarene scaffold acting as a structure-determining central platform is presented. In this tetrahedrally shaped amphiphilic architecture the hydrophilic and hydrophobic subunits are oriented at the opposite side of the calixarene platform. The hydrophobic part contains the two perylene diimide moieties, which enable strong π–π interactions in self-assembly processes. Two hydrophilic Newkome-type dendrons provide sufficien...

  2. Determination of the extractive capacity of para-tert butyl calix[8]arene octa-phosphinoylated towards uranyl ions from an aqueous-acidic-salty medium; Determinacion de la capacidad extractiva del p-ter-butilocalix[8]areno octa-fosfinoilado hacia iones uranilo de un medio acuo-acido salino

    Energy Technology Data Exchange (ETDEWEB)

    Serrano V, E. C.

    2011-07-01

    The extraction properties of octa-phosphinoylated para-tert butyl calix[8]arene (prepared in the laboratory) in chloroform towards uranyl ions from an aqueous-acidic-salty medium (HNO{sub 3}-3.5 NaNO{sub 3}) containing uranyl nitrate salt, was investigated. Two spectroscopic techniques UV/Vis and Luminescence were used for this study. The latter permitted analyze the fluorescence from the uranyl ions influenced by the surrounding medium. Both permitted to learn about the power of this calixarene as extractant towards the mentioned ions. Its extraction ability or capability using this calixarene at 5.91 x 10{sup -4} M towards the uranyl ions was 400% as determined by UV/Vis while fluorescence revealed 100% of uranyl ion extraction. A closed analysis of the results obtained by using these techniques revealed that the stoichiometry of the main extracted species was 1calixarene:2 uranyl ions. The loading capacity of the calixarene ligand towards the uranyl ions was also investigated using both techniques. UV/Vis resulted to be inadequate for quantifying exactly the loading capacity of the calixarene whereas luminescence was excellent indeed, using a 5.91 x 10{sup -4} M calixarene concentration, its loading capacity was 0.157 M of free uranyl ions from 0.161 M of uranyl ions present in the aqueous-acidic-salty medium. The extracts from the ability and capacity studies were concentrated to dryness, purified and the dried extracts were analyzed by infrared and neutron activation analysis. By these techniques it was demonstrated that during the extraction of the uranyl ions by the calixarene ligand they form thermodynamically and kinetically stable complexes, since in the solid state, the 1:2, calixarene; uranyl ions stoichiometry was kept with the minimum formula: (UO{sub 2}){sub 2}B{sub 8}bL{sup 8}(NO{sub 3}){sub 4}(H{sub 2}O){sub 4}CHCl{sub 3}(CH{sub 3}OH){sub 3} the methanol molecules come from its purification. It is proposed that B{sub 8}bL{sup 8} calixarene in

  3. Effect of Coordination Environment in Grafted Single-Site Ti-SiO_2 Olefin Epoxidation Catalysis

    OpenAIRE

    Grosso-Giordano, Nicolás A.; Solovyov, Andrew; Hwang, Sonjong; Katz, Alexander

    2016-01-01

    The effect of calixarene ligand symmetry, as dictated by lower-rim substitution pattern, on the coordination to a Ti(IV) cation is assessed in solution and when grafted on SiO_2, and its effect on epoxidation catalysis by Ti(IV)-calixarene grafted on SiO_2 is investigated. C_(2v) symmetric Ti-tert-butylcalix[4]arene complexes that are 1,3-alkyl disubstituted at the lower rim (di-R-Ti) are compared to previously reported grafted C_s symmetric complexes, which are singly substituted at the lowe...

  4. N-anthracenylmethyl calix[4]azacrowns as new fluorescent ionophores

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung H.; Shon, Ok J.; Kim, Jong S. [Konyang Univ., Nonsan (Korea, Republic of); Park, Ki M.; Lee, Shim S. [Gyeongsang National Univ., Chinju (Korea, Republic of); Park, Ho J.; Kim, Moon J. [Soonchunhyang Univ., Asan (Korea, Republic of); Lee, Joung H. [Korea Research Institute of Standards and Science, Daejon (Korea, Republic of)

    2002-11-01

    Two novel calixarene-based fluoroionophores were synthesized. Their conformations were confirmed to 1,3-alternate by X-ray crystal structures. From CHEF by blocking the PET mechanism in fluorescence spectra, we observed In{sup 3+} and Pb{sup 2+} ion selectivity over other metal ions. For In{sup 3+} ion, calix[4]-bis-azacrown-5 showed about 20 times more sensitive than calix[4]-mono-azacrown-5 because the source of the binding selectivity comes from the calixarene framework and azacrown ligand by controlling the fluorescence and PET mechanisms associated with the amine moiety.

  5. Synthesis of phosphorylated calix[4]arene derivatives for the design of solid phases immobilizing uranyl cations

    Energy Technology Data Exchange (ETDEWEB)

    Maroun, E.B.; Hagege, A.; Asfari, Z. [Laboratoire de Chimie Analytique et Minerale, UMR 7178 ULP/CNRS/IN2P3 LC4, ECPM, Strasbourg Cedex (France); Basset, CH.; Quemeneur, E.; Vidaud, C. [CEA IBEB, SBTN, Centre de Marcoule, Bagnols-sur-Ceze (France)

    2009-07-01

    With the aim of developing supports for uranyl cations immobilisation, new 1, 3-alternate calix[4]arenes bearing both phosphonic acid functions as chelating sites and N-succinimide-4-oxa-butyrate as the anchoring arm were synthesised in good yields. The coupling of such calixarenes to a gel was performed and a successful immobilisation of uranyl cations was obtained. (authors)

  6. A "plug-and-play" approach to the preparation of transparent luminescent hybrid materials based on poly(methyl methacrylate), a calix[4]arene cross-linking agent, and terbium ions.

    Science.gov (United States)

    Driscoll, Christopher R; Reid, Brodie L; McIldowie, Matthew J; Muzzioli, Sara; Nealon, Gareth L; Skelton, Brian W; Stagni, Stefano; Brown, David H; Massi, Massimiliano; Ogden, Mark I

    2011-04-07

    A novel methodology to prepare transparent luminescent hybrid materials is reported. Using a calixarene ionophore as a PMMA cross-linker avoids problems, such as phase segregation, and produces a polymer monolith that can be loaded with the metal ion required for luminescence post-synthesis. This approach is versatile and will simplify the production of such materials.

  7. Hybrid liposomal PEGylated calix[4]arene systems as drug delivery platforms for curcumin

    OpenAIRE

    Drakalska, Elena; Momekova, Denitsa; Manolova, Yana; Budurova, Desislava; Momekov, Georgi; Genova, Margarita; Antonov, Liudmil; Lambov, Nikolay; Rangelov, Stanislav

    2014-01-01

    The tremendous therapeutic potential of curcumin as a chemopreventive, antineoplastic and chemosensitizing agent has failed to progress towards clinical development and commercialization due to its unfavorable physicochemical properties, low aqueous solubility, chemical instability, and pharmacokinetics. The present contribution is focused on the feasibility of using PEGylated calixarene, in particular polyoxyethylene-derivatized tert-butylcalix[4]arene, to prepare various platforms for deliv...

  8. Synthesis, Crystal Structure, Theoretical Study, The

    Indian Academy of Sciences (India)

    Supramolecular Isomerism in Nonmolecular Solids? A case study of Copper Pyridazine Halides J. Chem. Sci. 128 1687. 15. Chen C, Ma J F, Liu B, Yang J and Liu Y Y 2011 Two. Unusual 3D Copper(II) Coordination Polymers Con- structed by p-Sulfonated Calixarenes and Bis(triazolyl). Ligands Cryst. Growth Des. 11 4491.

  9. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. RAJAA R ABBAS. Articles written in Bulletin of Materials Science. Volume 40 Issue 1 February 2017 pp 31-36. Fabrication, characterization and gas sensing properties of gold nanoparticle and calixarene multilayers · IINCI ÇAPAN ASEEL K HASSAN RAJAA R ABBAS.

  10. Calix[4]arene supported clusters: a dimer of [Mn(III)Mn(II)] dimers

    DEFF Research Database (Denmark)

    Taylor, Stephanie M; McIntosh, Ruaraidh D; Beavers, Christine M

    2011-01-01

    Phosphinate ligands allow for the transformation of a calix[4]arene supported [Mn(III)(2)Mn(II)(2)] tetramer cluster motif into an unusual [Mn(III)Mn(II)](2) dimer of dimers; the clusters self-assemble in the crystal to form bi-layer arrays reminiscent of the typical packing of calixarene solvates....

  11. Tailoring self-assembled monolayers at the electrochemical interface

    Indian Academy of Sciences (India)

    Administrator

    metal ions, molecular assemblies containing nano- cavitites, viz. cyclodextrins, calixarenes, carceplexes and so on. The applications include electron transfer kinetics, sensors, catalysis, etc. In this review, we discuss the different protocols that are reported in the literature to functionalize SAM modified inter- faces for different ...

  12. Colorimetric detection of Cu 2 and Pb 2 ions using calix [4] arene ...

    Indian Academy of Sciences (India)

    Calixarene functionalized gold nanoparticles (CFAuNPs) have been prepared and characterized by spectroscopic and microscopic (TEM) techniques. To use this material as potential colorimetric sensor, the binding property of this new material has been investigated with a large number of metal ions. It exhibited sharp ...

  13. Selective transport of ions and molecules across layer-by-layer assembled membranes of polyelectrolytes, p-sulfonato-calix[n]arenes and Prussian Blue-type complex salts.

    Science.gov (United States)

    Tieke, Bernd; Toutianoush, Ali; Jin, Wanqin

    2005-11-30

    Our recent studies in the field of ultrathin membranes prepared upon layer-by-layer assembly of various polyionic compounds such as polyelectrolytes, calixarenes and polyelectrolytes, and metal hexacyanoferrate salts such as Prussian Blue are reviewed. It is demonstrated that polyelectrolyte multilayers can be used (a) as nanofiltration and reverse osmosis membranes suitable for water softening and seawater desalination and (b) as molecular sieves and ion sieves for size-selective separation of neutral and charged aromatic compounds. Furthermore, hybrid membranes of p-sulfonato-calixarenes and cationic polyelectrolytes showing specific host-guest interactions with permeating ions are described. The membranes exhibit high selectivities for distinct metal ions. Finally, it is demonstrated that purely inorganic membranes of Prussian Blue (PB) and analogues can be prepared upon multiple sequential adsorption of transition metal cations and hexacyanoferrate anions. Due to the porous lattice of PB, the membranes are useful as ion filters able to separate cesium from sodium ions, for example.

  14. Polar self-assembled thin films for non-linear optical materials

    Science.gov (United States)

    Yang, XiaoGuang; Swanson, Basil I.; Li, DeQuan

    2000-01-01

    The design and synthesis of a family of calix[4]arene-based nonlinear optical (NLO) chromophores are discussed. The calixarene chromophores are macrocyclic compounds consisting of four simple D-.pi.-A units bridged by methylene groups. These molecules were synthesized such that four D-.pi.-A units of the calix[4]arene were aligned along the same direction with the calixarene in a cone conformation. These nonlinear optical super-chromophores were subsequently fabricated into covalently bound self-assembled monolayers on the surfaces of fused silica and silicon. Spectroscopic second harmonic generation (SHG) measurements were carried out to determine the absolute value of the dominant element of the second-order nonlinear susceptibility, d.sub.33, and the average molecular alignment, .PSI.. A value of d.sub.33 =60 pm/V at a fundamental wavelength of 890 nm, and .PSI..about.36.degree. was found with respect to the surface normal.

  15. Investigation of the mechanism of formation of overbased detergents

    CERN Document Server

    Courtois, J P

    2002-01-01

    This thesis describes an experimental study of calixarate overbased detergent oil additives, used to neutralise acidic by-products of engine combustion. Aspects of interest in this study include experimental synthesis of calixarenes and overbased detergents, physical and structural characterisation and monitoring of the synthesis process. Two types of calixarenes were prepared (6 and 8 phenolic units). A synthesis procedure of the calixarate overbased detergent was set up, based on adaptation of existing procedures used for other classes of overbased detergents. The procedure was also modified to suit a lab-scale. sup 1 sup 3 C NMR and UV-Vis spectroscopy have provided strong evidence for a precursor of the overbased detergent. The ionisation of the surfactants (stearic acid carboxylic group, and phenolic units) was clearly established. The synthesis process was monitored at the molecular and macroscopic level. The use of sup 1 sup 3 C-labelled compounds enabled a semi-quantitative study of the concentration ...

  16. Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

    Directory of Open Access Journals (Sweden)

    Silvia Bernardi

    2014-07-01

    Full Text Available Four novel calix[4]arene-based glycoclusters were synthesized by conjugating the saccharide units to the macrocyclic scaffold using the CuAAC reaction and using long and hydrophilic ethylene glycol spacers. Initially, two galactosylcalix[4]arenes were prepared starting from saccharide units and calixarene cores which differ in the relative dispositions of the alkyne and azido groups. Once the most convenient synthetic pathway was selected, two further lactosylcalix[4]arenes were obtained, one in the cone, the other one in the 1,3-alternate structure. Preliminary studies of the interactions of these novel glycocalixarenes with galectin-3 were carried out by using a lectin-functionalized chip and surface plasmon resonance. These studies indicate a higher affinity of lactosyl- over galactosylcalixarenes. Furthermore, we confirmed that in case of this specific lectin binding the presentation of lactose units on a cone calixarene is highly preferred with respect to its isomeric form in the 1,3-alternate structure.

  17. Pillar[5]arene-based diglycolamides for highly efficient separation of americium(III) and europium(III).

    Science.gov (United States)

    Wu, Lei; Fang, Yuyu; Jia, Yiming; Yang, Yuanyou; Liao, Jiali; Liu, Ning; Yang, Xinshi; Feng, Wen; Ming, Jialin; Yuan, Lihua

    2014-03-14

    Pillar[5]arenes, as a new intriguing class of calixarene analogues, were functionalized with ten diglycolamide (DGA) arms on both sides (rims) of the pillar framework and evaluated for their extraction behaviour towards Am(III) and Eu(III). These novel extractants exhibit excellent separation and extraction efficiency, suggesting its significant potential for nuclear waste remediation. Laser induced fluorescence experiments disclosed strong complexation of the trivalent metal ions with the pillararene-DGA ligands.

  18. Élaboration de matériaux moléculaires à partir d'unités calixaréniques

    OpenAIRE

    Ben Maamar, Sami

    2008-01-01

    During this work of thesis, new calixarenes complexing selectively metal ions have been synthesized. After a bibliographic presentation, a calix[4]arene containing organosiloxane group has been synthesized and grafted on a periodically mesoporous SBA-15. The multiple characterization techniques, such as XRD, nitrogen adsorption, TEM, FT-IR and solid state 29Si NMR, as well as TG indicate that the calix[4]arene derivative has been well-anchored on the surface of SBA-15 generating a new class o...

  19. Polyoxomolybdate-Calix[4]arene Hybrid: A Catalyst for Sulfoxidation Reactions with Hydrogen Peroxide.

    Science.gov (United States)

    Meninno, Sara; Parrella, Alessandro; Brancatelli, Giovanna; Geremia, Silvano; Gaeta, Carmine; Talotta, Carmen; Neri, Placido; Lattanzi, Alessandra

    2015-10-16

    An easily accessible polyoxomolybdate-calix[4]arene hybrid 1 has been synthesized and applied as a heterogeneous catalyst in the sulfoxidation of thioethers to sulfoxides and to sulfones under strictly stoichiometric amounts of 30% H2O2 in CH3CN as the solvent. This study represents the first promising example of successful employment of calixarenes-polyoxometalate (POM) hybrid materials in the area of catalytic oxidations.

  20. Diphosphines with expandable bite angles: highly active ethylene dimerisation catalysts based on upper rim, distally diphosphinated calix[4]arenes.

    Science.gov (United States)

    Lejeune, Manuel; Sémeril, David; Jeunesse, Catherine; Matt, Dominique; Peruch, Frédéric; Lutz, Pierre J; Ricard, Louis

    2004-10-25

    The binding properties of two large diphosphines, cone-5,17-dibromo-11,23-bis(diphenylphosphino)-25,26,27,28-tetrapropoxycalix[4]arene (1) and cone-5,17-bis(diphenylphosphino)-25,26,27,28-tetrapropoxycalix[4]arene (2) toward Ni(II) centres have been investigated. Whatever the starting complex, NiBr2 or [NiCp]BF4, quantitative formation of a chelate complex was observed, illustrating the preorganisation of the ligands. An X-ray structure determination was carried out for [NiCp1]BF4 which revealed that the nickel atom is positioned to one side of the calixarene axis, the PNiP plane being roughly parallel to the calixarene reference plane. The molecule has C(1) symmetry in the solid state, a feature which is also observed in solution at low temperature. As shown by variable-temperature 1H and 31P NMR studies, the complex undergoes two distinct motions: 1) a fan-like swinging of the coordination plane which displaces the metal from one side of the calixarene axis to the other, a motion during which the PNiP angle is likely to undergo a significant enlargement; 2) a rapid oscillation of each PPh2 unit about the corresponding Ni--P bond. In the latter dynamics the two endo-oriented PPh rings alternately occupy the calixarene entry. The two flexible ligands were assessed in ethylene oligomerisation. Activation with methylaluminoxane of the paramagnetic complexes [NiBr2.(1 or 2)] afforded highly active ethylene dimerisation catalysts, with turnover frequencies up to 10(6) (mol C2H4) (mol Ni)(-1) h(-1). The selective formation of 1-butene can be rationally controlled by using low catalyst concentrations.

  1. Nouveaux complexes biomimétiques dérivés de calix[6]azacryptands :étude des effets de seconde sphère et greffage sur surface

    OpenAIRE

    De Leener, Gaël

    2016-01-01

    More than 30% of all enzymes present a metal ion in their active site. Interesting sub-families present a mononuclear active site where a single metal ion (Zn2+ or Cun+) is coordinated to a polyhistidine core. The elaboration of model compounds is important for understanding the fundamental mechanisms involved in their bio-catalytic cycles. In this context, we have developed calix[6]arene based ligands presenting an aza cap covalently linked to the calixarene moiety. These supramolecular asse...

  2. Coordination of lead(II) in the supramolecular environment provided by a "two-story" calix[6]arene-based N6 ligand.

    Science.gov (United States)

    Over, Diana; Zeng, Xianshun; Bornholdt, Claudia; Marrot, Jérôme; Reinaud, Olivia

    2013-12-16

    First insights into the coordination properties and host-guest behavior of a "two story" calix[6]aza-cryptand (1) are described. The ligand is constituted of a triazacyclononane (TACN) cap and three pyridine (PY) spacers connected to the calix[6]arene small rim. The resulting N6 donor site coordinates Pb(II) ions to give complexes that are highly stable. X-ray diffraction structures reveal a hemidirected environment for Pb(II) with strong coordination to the TACN cap and weaker bonds with the three PY residues. A guest molecule, either water or EtOH, sitting in the calixarene macrocycle and hydrogen-bonded to the phenoxyl units at the level of the small rim further stabilizes the complexes through electrostatic interactions with the metal center and the calixarene core. In-depth (1)H NMR studies confirm the host-guest behavior of the complexes in solution, with evidence of embedment of neutral guest molecules such as EtOH, BuOH, and N-Me-formamide. Hence, in spite of the presence of a N6 donor, the calixarene macrocycle can be open to guest interaction, giving rise to seven-coordinate dicationic complexes. Noteworthy also is the flexibility of the macrocycle that allows Pb(II) to adopt its preferred hemidirected environment in spite of the three covalent links connecting the calixarene core to the three PY groups. The flexibility of the system is further illustrated by the possible coordination of an exogenous anionic ligand in the exo position. Hence, compared to the previously described "one story" calix[6]aza-cryptands, ligand 1 displays several similar but also new features that are discussed.

  3. Glycopeptide dendrimers. Part I

    Czech Academy of Sciences Publication Activity Database

    Niederhafner, Petr; Šebestík, Jaroslav; Ježek, Jan

    2008-01-01

    Roč. 14, č. 1 (2008), s. 2-43 ISSN 1075-2617 R&D Projects: GA ČR GA203/03/1362; GA ČR GA203/06/1272; GA MZe QF3115; GA AV ČR KAN200520703 Institutional research plan: CEZ:AV0Z40550506 Keywords : artificial virus * calixarene dendrimers * carbopeptide dendrimers * glycopeptide dendrimers Subject RIV: CC - Organic Chemistry Impact factor: 1.654, year: 2008

  4. First synthesis of a '1,2-diquinone-calix[4]arene'. Interaction of its reduced form with Ag+

    OpenAIRE

    Vataj, Rame; Ridaoui, Hassan; Louati, Alain; Gabelica, Valérie; Steyer, Stéphane; MATT, DOMINIQUE

    2002-01-01

    Electrochemical oxidation of 5,11,17,23-tetra-tert-butyl-25,26-bis(diphenylphosphinoylmethoxy)-27,28-dihydroxycalix[4]arene (3), a calixarene with two phosphoryl units appended on proximal positions, affords the corresponding '1,2-diquinonecalix[4]arene' (4). The formation of 4 results from nucleophilic attack of residual water on anodically generated diphenoxylium. cations. Preliminary voltammetric experiments in CH3CN on a platinum electrode showed that 4 is suitable for electrochemical det...

  5. Ingénierie moléculaire et fluorescence pour la reconnaissance de cations toxiques

    OpenAIRE

    Souchon, Vincent

    2007-01-01

    This work is a part of the “Toxicologie Nucléaire Environnementale” program which aims at studying the effects on the living of heavy metals or radionuclides involved in nuclear industry. Most particularly, it deals with the design of new fluorescent sensors for the selective detection of Pb2+, Cd2+ and Cs+ in biological media. Several fluorescent calixarenes possessing nitrogen atoms were synthesized and their properties as potential lead sensors were investigated. One of them could be used ...

  6. Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, F. de M. [Instituto Nacional de Investigaciones Nucleares, La Marquesa, Ocoyoacac (Mexico). Dept. de Quimica; Varbanov, S. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Organic Chemistry with Center of Phytochemistry; Buenzli, J.C.G. [Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland). Inst. of Chemical Sciences and Engineering; Rivas-Silva, J.F.; Ocana-Bribiesca, M.A. [Instituto de Fisica de la BUAP, Puebla (Mexico); Cortes-Jacome, M.A.; Toledo-Antonio, J.A. [Instituto Mexicano del Petroleo/Programa de Ingenieria Molecular (Mexico)

    2012-07-01

    The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1:1 and 1:2 (M:L) complexes with a tetra-phosphinoylated p-tert-butylcalix[4]arene, B{sub 4}bL{sup 4}: UO{sub 2}(NO{sub 3}){sub 2}(B{sub 4}bL{sup 4}){sub n} . xH{sub 2}O (n = 1, x = 2, 1; n = 2, x = 6, 2). Spectroscopic data point to the inner coordination sphere of 1 containing one monodentate nitrate anion, one water molecule and the four phosphinoylated arms bound to UO{sub 2}{sup 2+} while in 2, uranyl is only coordinated to calixarene ligands. In both cases the U(VI) ion is 8-coordinate. Uranyl complexes display enhanced metal-centred luminescence due to energy transfer from the calixarene ligands; the luminescence decays are bi-exponential with associated lifetimes in the ranges 220 {mu}s < {tau}{sub s} < 250 {mu}s and 630 {mu}s < {tau}{sub L} < 640 {mu}s, pointing to the presence of two species with differently coordinated calixarene, as substantiated by a XPS study of U(4f{sub 5/2,7/2}), O(1s) and P(2p) levels on solid state samples. The extraction study of UO{sub 2}{sup 2+} cation and trivalent rare-earth (Y, La, Eu) ions from acidic nitrate media by B{sub 4}bL{sup 4} in chloroform shows the uranyl cation being much more extracted than rare earths. (orig.)

  7. Calix[4]arene daisychains.

    Science.gov (United States)

    Sameni, Soheila; Jeunesse, Catherine; Matt, Dominique; Harrowfield, Jack

    2009-07-01

    Generic calix[4]arenes became readily accessible in the late 70s. With their potential eight anchoring points, their utility for the production of sophisticated, highly functionalised macrocyclic molecules was rapidly recognised. While most studies in calixarene chemistry have focused on monocalixarene derivatives, there is now an increasing interest in developing multicalixarene compounds, especially those made of several linearly-arranged calix[4]arene units, the first examples of which were reported in 1989. This critical review will present the most important synthetic routes to such molecules together with an analysis of the properties that such cavity combinations may induce. In particular it will be shown that the nature of the links between the calixarene units plays a determinant role in the product properties and that singly-linked calixarenes can be exploited in varied applications, including those as efficient receptors of large molecules, as electrochemical and luminescent sensors in ion detection, or as new materials allowing capsule formation suitable for the storage of small guests (82 references).

  8. Towards supramolecular fixation of NOX gases: encapsulated reagents for nitrosation.

    Science.gov (United States)

    Kang, Yanlong; Zyryanov, Grigory V; Rudkevich, Dmitry M

    2005-03-04

    The use of simple calix[4]arenes for chemical conversion of NO2/N2O4 gases is demonstrated in solution and in the solid state. Upon reacting with these gases, calixarenes 1 encapsulate nitrosonium (NO+) cations within their cavities with the formation of stable calixarene-NO+ complexes 2. These complexes act as encapsulated nitrosating reagents; cavity effects control their reactivity and selectivity. Complexes 2 were effectively used for nitrosation of secondary amides 5, including chiral derivatives. Unique size-shape selectivity was observed, allowing for exclusive nitrosation of less crowded N-Me amides 5 a-e (up to 95 % yields). Bulkier N-Alk (Alk>Me) substrates 5 did not react due to the hindered approach to the encapsulated NO+ reagents. Robust, silica gel based calixarene material 3 was prepared, which reversibly traps NO2/N2O4 with the formation of NO+-storing silica gel 4. With material 4, similar size-shape selectivity was observed for nitrosation. The N-Me-N-nitroso derivatives 6 d,e were obtained with approximately 30 % yields, while bulkier amides were nitrosated with much lower yields (environment and biomedical areas.

  9. Plugging a Bipyridinium Axle into Multichromophoric Calix[6]arene Wheels Bearing Naphthyl Units at Different Rims.

    Science.gov (United States)

    Orlandini, Guido; Ragazzon, Giulio; Zanichelli, Valeria; Degli Esposti, Lorenzo; Baroncini, Massimo; Silvi, Serena; Venturi, Margherita; Credi, Alberto; Secchi, Andrea; Arduini, Arturo

    2017-02-01

    Tris-(N-phenylureido)-calix[6]arene derivatives are heteroditopic non-symmetric molecular hosts that can form pseudorotaxane complexes with 4,4'-bipyridinium-type guests. Owing to the unique structural features and recognition properties of the calix[6]arene wheel, these systems are of interest for the design and synthesis of novel molecular devices and machines. We envisaged that the incorporation of photoactive units in the calixarene skeleton could lead to the development of systems the working modes of which can be governed and monitored by means of light-activated processes. Here, we report on the synthesis, structural characterization, and spectroscopic, photophysical, and electrochemical investigation of two calix[6]arene wheels decorated with three naphthyl groups anchored to either the upper or lower rim of the phenylureido calixarene platform. We found that the naphthyl units interact mutually and with the calixarene skeleton in a different fashion in the two compounds, which thus exhibit a markedly distinct photophysical behavior. For both hosts, the inclusion of a 4,4'-bipyridinium guest activates energy- and/or electron-transfer processes that lead to non-trivial luminescence changes.

  10. Elaboration of hybrid organic-inorganic materials for ammonium ions retention: Electron microscopy bipolarized observations and {sup 129}Xe solid-state NMR

    Energy Technology Data Exchange (ETDEWEB)

    Barthelemy, A.; Duchamp, C.; Uttaro, J.-P. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne, F-69622 (France); CNRS, UMR 5246, ICBMS, equipe CSAp, Villeurbanne, F-69622 (France); Rousseau, C. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne F-69622, France, IBCP, UMR 5086, Lyon, F-69367 (France); Fenet, B. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne, F-69622 (France); Centre Commun de RMN, Villeurbanne, F-69622 (France); Ananchenko, G.; Lang, S. [Steacie Institute for Molecular Sciences, NRC, 100 Sussex drive, Ottawa, Ontario, K1A 0R6 (Canada); Coleman, A.W. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne F-69622 (France); IBCP, UMR 5086, Lyon, F-69367 (France); Ripmeester, J. [Steacie Institute for Molecular Sciences, NRC, 100 Sussex drive, Ottawa, Ontario, K1A 0R6 (Canada); Guillard, C. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne F-69622 (France); IRCELyon, UMR 5256, Villeurbanne, F-69622 (France); Elsellami, L. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne, F-69622 (France); CNRS, UMR 5246, ICBMS, equipe CSAp, Villeurbanne, F-69622 (France); Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne F-69622 (France); IRCELyon, UMR 5256, Villeurbanne, F-69622 (France); Lamartine, R.; Felix, C. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne, F-69622 (France); CNRS, UMR 5246, ICBMS, equipe CSAp, Villeurbanne, F-69622 (France); Vocanson, F. [Universite de Lyon, Lyon, F-69003 (France); Universite Lyon 1, Villeurbanne, F-69622 (France); CNRS, UMR 5246, ICBMS, equipe CSAp, Villeurbanne, F-69622 (France)], E-mail: francis.vocanson@univ-lyon1.fr

    2008-07-01

    Translucent organic-inorganic hybrid porous silica materials have been prepared via the acid-catalysed hydrolysis and condensation of TEOS and various p-sulphonatocalix[n]arene derivatives. Xerogels and aerogels have been prepared. The morphology of the gels was characterized by electron microscopy (SEM and ESEM) and by hyperpolarized {sup 129}Xe NMR. The aerogels showed a porous structure not influenced by the size of the calixarene derivative incorporated in the gel. The efficiency of these new materials towards the retention of ammonium ions was discussed.

  11. Hierarchical host-guest assemblies formed on dodecaborate-coated gold nanoparticles.

    Science.gov (United States)

    Assaf, Khaleel I; Hennig, Andreas; Peng, Shu; Guo, Dong-Sheng; Gabel, Detlef; Nau, Werner M

    2017-04-20

    Undecahydro-mercapto-closo-dodecaborate (BSH), a purely inorganic cluster anion, serves as an unconventional stabilizing ligand for the preparation of gold nanoparticles (AuNPs). The BSH-capped AuNPs serve as nano-scaffolds, allowing for the creation of supramolecular architectures by using polycationic macrocyclic host molecules, through strong host-guest complexation. An amphiphilic calixarene (CX) forms first mono- and subsequently bi-layer assemblies on the BSH-AuNP surfaces depending on the CX concentration. The inorganic-organic hybrid materials, combined with host-dye displacement assays, serve as a chemosensing ensemble for negatively charged molecules, including DNA.

  12. Synthesis and studies of a water-soluble and air-stable Cu(I)/Cu(II) open-shell funnel complex.

    Science.gov (United States)

    Thiabaud, Grégory; Brugnara, Andrea; Carboni, Michael; Le Poul, Nicolas; Colasson, Benoît; Le Mest, Yves; Reinaud, Olivia

    2012-05-18

    The derivatization of the large rim of a TMPA-capped calix[6]arene (TMPA = tris(2-pyridylmethyl)amine) with three trimethylammonium groups enables the water-solubilization of two air-stable Cu(I)/Cu(II) complexes. These two complexes present a vacant coordination site shielded from the aqueous environment by the calixarene core. The spectroscopic and electrochemical data recorded in pure water indicate that the host-guest properties of the funnel complex are retained in both oxidation states of the copper cation.

  13. Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

    Directory of Open Access Journals (Sweden)

    Bernd Garska

    2010-08-01

    Full Text Available We describe the calixarene-cyclodextrin-coupling via click reaction starting from 5,11,17,23-tetra-tert-butyl-25,27-dipropargylether-26,28-hydroxy-calix[4]arene (calix[4]arene-dipropargylether (2 onto 6I-azido-6I-deoxycyclomaltoheptaose (3 under microwave assisted conditions. The coupling was proven by MALDI-TOF mass spectrometry, 1H NMR and IR-spectroscopy. The pH dependent supramolecular complex formation with poly(NIPAAM bearing attached adamantyl units was investigated by dynamic light scattering (DLS and turbidity measurements.

  14. Fluorescent and colorimetric sensors for detection of lead, cadmium, and mercury ions.

    Science.gov (United States)

    Kim, Ha Na; Ren, Wen Xiu; Kim, Jong Seung; Yoon, Juyoung

    2012-04-21

    Exposure to even very low levels of lead, cadmium, and mercury ions is known to cause neurological, reproductive, cardiovascular, and developmental disorders, which are more serious problems for children particularly. Accordingly, great efforts have been devoted to the development of fluorescent and colorimetric sensors, which can selectively detect lead, cadmium, and mercury ions. In this critical review, the fluorescent and colorimetric sensors are classified according to their receptors into several categories, including small molecule based sensors, calixarene based chemosensors, BODIPY based chemosensors, polymer based chemosensors, DNA functionalized sensing systems, protein based sensing systems and nanoparticle based sensing systems (197 references). This journal is © The Royal Society of Chemistry 2012

  15. Synthesis and biological evaluation of lipophilic teicoplanin pseudoaglycon derivatives containing a substituted triazole function.

    Science.gov (United States)

    Szűcs, Zsolt; Csávás, Magdolna; Rőth, Erzsébet; Borbás, Anikó; Batta, Gyula; Perret, Florent; Ostorházi, Eszter; Szatmári, Réka; Vanderlinden, Evelien; Naesens, Lieve; Herczegh, Pál

    2017-02-01

    A series of lipophilic teicoplanin pseudoaglycon derivatives, including alkyl-, aryl-, calixarene- and protected sugar-containing conjugates, were prepared using azide-alkyne click chemistry. Out of the conditions applied, the CuSO4-ascorbate reagent system proved to be more efficient than the Cu(I)I-Et3N-mediated reaction. Some of the new compounds have high in vitro activity against glycopeptide-resistant Gram-positive bacteria, including vanA-positive Enterococcus faecalis. A few of them also display promising in vitro anti-influenza activity.

  16. Hydroxyquinoline-calix[4]arene-conjugates as ligands for lanthanide complexes. Preparation, characterization, and extraction properties

    Energy Technology Data Exchange (ETDEWEB)

    Mansel, Alexander [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Jaeschke, A.; Kischel, M.; Kersting, B. [Leipzig Univ. (Germany). Inst. fuer Anorganische Chemie

    2017-06-01

    The synthesis of a calixarene-based N{sub 4}O{sub 4} donor ligand H{sub 6}L, in which two 8-hydroxyquinoline-2-carbaldehyde units are appended via hydrazone-carbonylmethoxy linkages in a 1,3-arrangement to the lower rim of tert-butyl-calix[4]arene and its coordination properties towards Eu{sup 3+} are described. Moreover, the ligand H{sub 6}L was found to extract Eu{sup 3+} and Tb{sup 3+} at pH 7-8 from aqueous solution, as established by radiotracing using the radionuclides {sup 160}Tb and {sup 152} Eu.

  17. The synthesis and alkylation of p-tetrakischloro-calix[4]arene

    Directory of Open Access Journals (Sweden)

    E. A. Ivanova

    2014-11-01

    Full Text Available This work is devoted to the development of a chlorination of a calixarenes and a testing of the methods for their preparation to investigate the biological activity of the obtained compounds. New convinient undescribed in the literature methods of the chlorination using sulphuryl chloride or sodium hypochlorite were designed. By the using de-tert-butylcalix[4]arene, containing lower rin the ethoxy(hydroxycarbonyl metoxy groups, as the starting compounds in the same reactin l aed to mixture of the produts. The reaction of the calix[4]arene and the sulfuryl chloride led to the tetra-kis-chlorocalix[4]arene with good yield (95 %.

  18. Shear induced carboplatin binding within the cavity of a phospholipid mimic for increased anticancer efficacy

    Science.gov (United States)

    Mo, Jingxin; Eggers, Paul K.; Chen, Xianjue; Ahamed, Muhammad Rizwan Hussain; Becker, Thomas; Yong Lim, Lee; Raston, Colin L.

    2015-01-01

    Vesicles 107 ± 19 nm in diameter, based on the self-assembly of tetra-para-phosphonomethyl calix[4]- arene bearing n-hexyl moieties attached to the phenolic oxygen centres, are effective in binding carboplatin within the cavity of the macrocycle under shear induced within a dynamic thin film in a continuous flow vortex fluidic device. Post shearing the vesicles maintain similar diameters and retain carboplatin within the cavity of the calixarene in a hierarchical structure, with their size and morphology investigated using DLS, TEM, SEM and AFM. Location of the carboplatin was confirmed using NMR, FTIR, ESI-MS and EFTEM, with molecular modelling favouring the polar groups of carboplatin hydrogen bonded to phosphonic acid moieties and the four member cyclobutane ring directed into the cavity of the calixarene. The loading efficiency and release profile of carboplatin was investigated using LC-TOF/MS, with the high loading of the drug achieved under shear and preferential released at pH 5.5, offering scope for anti-cancer drug delivery. The hierarchical structured vesicles increase the efficacy of carboplatin by 4.5 fold on ovarian cancer cells, lowered the IC50 concentration by 10 fold, and markedly increased the percent of cells in the S-phase (DNA replication) of the cell cycle. PMID:26000441

  19. Structural and spectroscopic investigation of new luminescent hybrid materials based on calix[4]arene-tetracarboxylate and Ln3+ ions (Ln = Gd, Tb or Eu)

    Science.gov (United States)

    Viana, R. S.; Oliveira, C. A. F.; Chojnacki, J.; Barros, B. S.; Alves-Jr, S.; Kulesza, J.

    2017-07-01

    Lanthanide-calixarene hybrid materials are of particular interest due to the combination of the interesting properties of the ligand cavity-like structure and the luminescent features of lanthanides. The aim of this study was to synthesize and investigate the photophysical properties of Eu3+, Tb3+ and Gd3+ hybrids based on calix[4]arene-tetracarboxylate. The preparation of two structurally different Tb3+ compounds (calix-TA-SC-Tb and calix-TA-Tb) was dictated by the ligand to metal molar ratio and the synthesis time. Analysis of calix-TA-SC-Tb monocrystals revealed the formation of a mononuclear complex of C2 symmetry containing Tb3+ coordinated by four calixarene ionized groups and formate anion encapsulated within the upper cavity. Syntheses of other hybrids failed in producing high-quality crystals and the structures could not be solved. The solid-state luminescent properties of hybrids were evaluated, and the structure/property relationship was investigated. Based on the emission and excitation spectra, the energy diagrams for calix-TA-Eu, calix-TA-Tb and calix-TA-Gd were proposed.

  20. Texturing formulations for uranium skin decontamination.

    Science.gov (United States)

    Belhomme-Henry, Corinne; Phan, Guillaume; Huang, Nicolas; Bouvier, Céline; Rebière, François; Agarande, Michelle; Fattal, Elias

    2014-09-01

    Since no specific treatment exists in case of cutaneous contamination by radionuclides such as uranium, a nanoemulsion comprising calixarene molecules, known for their good chelation properties, was previously designed. However, this fluid topical form may be not suitable for optimal application on the skin or wounds. To develop a texturing pharmaceutical form for the treatment of wounded skins contaminated by uranium. The formulations consisted in oil-in-water (O/W) nanoemulsions, loaded with calixarene molecules. The external phase of the initial liquid nanoemulsion was modified with a combination of thermosensitive gelifying polymers: Poloxamer and HydroxyPropylMethylcellulose (HPMC) or methylcellulose (MC). These new formulations were characterized then tested by ex vivo experiments on Franz cells to prevent uranyl ions diffusion through excoriated pig ear skin explants. Despite strong changes in rheological properties, the physico-chemical characteristics of the new nanoemulsions, such as the size and the zeta potential as well as macroscopic aspect were preserved. In addition, on wounded skin, diffusion of uranyl ions, measured by ICP-MS, was limited to less than 5% for both HPMC and MC nanoemulsions. These results demonstrated that a hybrid formulation of nanoemulsion in hydrogel is efficient to treat uranium skin contamination.

  1. Amphiphilic perylene-calix[4]arene hybrids: synthesis and tunable self-assembly.

    Science.gov (United States)

    Rodler, Fabian; Schade, Boris; Jäger, Christof M; Backes, Susanne; Hampel, Frank; Böttcher, Christoph; Clark, Timothy; Hirsch, Andreas

    2015-03-11

    The first highly water-soluble perylene-calix[4]arene hybrid with the calixarene scaffold acting as a structure-determining central platform is presented. In this tetrahedrally shaped amphiphilic architecture the hydrophilic and hydrophobic subunits are oriented at the opposite side of the calixarene platform. The hydrophobic part contains the two perylene diimide moieties, which enable strong π-π interactions in self-assembly processes. Two hydrophilic Newkome-type dendrons provide sufficient water solubility at slightly basic conditions. The tetrahedrally shaped amphiphile displays an unprecedented aggregation behavior down to concentrations as low as 10(-7) mol L(-1). The intriguing self-assembly process of the compound in water as well as under changed polarity conditions, achieved by addition of THF, could be monitored by the complemented use of cryogenic transmission electron microscopy (cryo-TEM), UV-vis spectroscopy, and fluorescence spectroscopy. Molecular-dynamics and molecular modeling simulations helped in understanding the interplay of supramolecular and optical behavior.

  2. Inhibition of histone binding by supramolecular hosts

    Science.gov (United States)

    Allen, Hillary F.; Daze, Kevin D.; Shimbo, Takashi; Lai, Anne; Musselman, Catherine A.; Sims, Jennifer K.; Wade, Paul A.; Hof†, Fraser; Kutateladze, Tatiana G.

    2015-01-01

    The tandem PHD (plant homeodomain) fingers of the CHD4 (chromodomain helicase DNA-binding protein 4) ATPase are epigenetic readers that bind either unmodified histone H3 tails or H3K9me3 (histone H3 trimethylated at Lys9). This dual function is necessary for the transcriptional and chromatin remodelling activities of the NuRD (nucleosome remodelling and deacetylase) complex. In the present paper, we show that calixarene-based supramolecular hosts disrupt binding of the CHD4 PHD2 finger to H3K9me3, but do not affect the interaction of this protein with the H3K9me0 (unmodified histone H3) tail. A similar inhibitory effect, observed for the association of chromodomain of HP1γ (heterochromatin protein 1γ) with H3K9me3, points to a general mechanism of methyl-lysine caging by calixarenes and suggests a high potential for these compounds in biochemical applications. Immunofluorescence analysis reveals that the supramolecular agents induce changes in chromatin organization that are consistent with their binding to and disruption of H3K9me3 sites in living cells. The results of the present study suggest that the aromatic macrocyclic hosts can be used as a powerful new tool for characterizing methylation-driven epigenetic mechanisms. PMID:24576085

  3. Phosphorus-phosphorus coupling in a diphosphine with a ten bond P...P separation.

    Science.gov (United States)

    Kuhn, P; Jeunesse, C; Matt, D; Harrowfield, J; Ricard, L

    2006-07-28

    The large, unsymmetrical diphosphine 5,11,17,23-tetra-tert-butyl-25,26-bis(diphenylphosphinomethoxy)-27(or 28)-benzoyloxy-28(or 27)-hydroxycalix[4]arene, in which the phosphorus atoms are separated by ten bonds, was prepared by monobenzoylation of 5,11,17,23-tetra-tert-butyl-25,26-bis(diphenylphosphinoylmethoxy)-27,28-bis(hydroxy)calix[4]arene, followed by reduction with phenyl silane. Its molecular structure has been determined by X-ray crystallography. In the solid state, the phosphorus atoms are separated by 5.333(1) A. NMR investigations reveal an unexpected "through-space"J(PP') coupling constant of 8.0 Hz and also show that, in solution, the calixarene is conformationally mobile, the phenoxy ring flipping rapidly through the calixarene annulus. The spatial proximity of the two phosphorus atoms was further demonstrated by the ease of obtaining the cis-chelate complex [Pd(eta3-C3H4Me)(THF)2]BF4 (THF = tetrahydrofuran).

  4. Extraction of americium and europium by CMPO-substituted adamantylcalixarenes

    Energy Technology Data Exchange (ETDEWEB)

    Babain, V.A.; Alyapyshev, M.Yu.; Karavan, M.D. [V.G. Khlopin Radium Inst., St. Petersburg (Russian Federation); Boehmer, V.; Wang, L. [Johannes Guttenberg Univ., Mainz (Germany); Shokova, E.A.; Motornaya, A.E.; Vatsouro, I.M.; Kovalev, V.V. [M. V. Lomonosov Moscow State Univ., Moscow (Russian Federation)

    2005-07-01

    Eight p-adamantylcalix[4]arene derivatives, bearing four CMPO-like functions [-(CH{sub 2}){sub n}-NH-C(O)-CH{sub 2-}P(O)Ph{sub 2}] at the wide (4a,b, n = 0, 1) or narrow (5a-c and 6a-c, n = 2-4) rims were synthesized for the first time. Studies of the extraction of americium(III) and europium(III) from 3 M HNO{sub 3} solutions to organic phases (dichloromethane, m-nitro-trifluoromethylbenzene) showed: (i) The extraction ability for all the adamantylcalixarene ligands is much better than for their monomeric analogues -N-(1-adamantyl)-, N-(1-adamantylmethyl)- and N,N-(dibutyl)carbamoylmethyldiphenylphosphine oxides 7a, 7b, 8; (ii) The extraction percentage increases strongly with increasing length of the spacer for all types of ligands 4-6, and best extraction results were found for 4b (n = 1) and 5c (n = 4); (iii) The separation coefficient D{sub Am}/D{sub Eu} for the investigated compounds did not exceed 2, which is close to the narrow rim CMPO calixarenes, studied earlier; (iv) Variation of the spacer length between CMPO groups attached to the 1,3- and 2,4-positions of the calixarene platform in 6 did not lead to appreciably improved extractants, neither with respect to the extraction abilities (D) nor to the selectivities (D{sub Am}/D{sub Eu}). (orig.)

  5. Hybrid liposomal PEGylated calix[4]arene systems as drug delivery platforms for curcumin.

    Science.gov (United States)

    Drakalska, Elena; Momekova, Denitsa; Manolova, Yana; Budurova, Dessislava; Momekov, Georgi; Genova, Margarita; Antonov, Liudmil; Lambov, Nikolay; Rangelov, Stanislav

    2014-09-10

    The tremendous therapeutic potential of curcumin as a chemopreventive, antineoplastic and chemosensitizing agent has failed to progress towards clinical development and commercialization due to its unfavorable physicochemical properties, low aqueous solubility, chemical instability, and pharmacokinetics. The present contribution is focused on the feasibility of using PEGylated calixarene, in particular polyoxyethylene-derivatized tert-butylcalix[4]arene, to prepare various platforms for delivery of curcumin such as inclusion complex, supramolecular aggregates, and hybrid liposomal systems. The inclusion complex is characterized by UV-vis and FT-IR spectroscopy as well as thermal gravimetrical analysis and differential scanning calorimetry. At concentrations exceeding the critical micellization concentration of PEGylated calixarene, the tremendous solubility enhancement of curcumin is attributed to additional solubilization and hydrophobic non-covalent interactions of the drug with supramolecular aggregates. A hybrid liposomal system is created via encapsulation of the inclusion complex in dipalmitoylphosphatidylcholine:cholesterol liposomes. Bare and liposomal curcumin:BEC-X inclusion complexes, as well as free curcumin were additionally investigated for cytotoxicity and apoptogenic activity against human tumor cell lines. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Amino acids separation with the tetracarboxylic derived of the para-ter-butylcalix[4]arene by means of solid-liquid extraction assisted with lanthanides; Separacion de aminoacidos con el derivado tetracarboxilico del para-ter-butilcalix[4]areno mediante extraccion solido-liquido asistida con lantanidos

    Energy Technology Data Exchange (ETDEWEB)

    Bernal R, R. del C.

    2014-07-01

    The tetracarboxylic derived of the para-ter-butylcalix[4]arene (B{sub 4}ACEbL{sup 4}) does not exist commercially for what was synthesized and characterized at laboratory level. The separation of the L-tyrosine amino acid was studied by means of a solid-liquid extraction system with the B{sub 4}ACEbL{sup 4} as solid phase, in function of ph (2.5-7.5) and contact time (5 and 15 hours) to temperature of 15-17 grades C. Resulted that the ph and the contact time were decisive in the extraction percentage of water tyrosine. The lowest percentage was 49% to ph 4 and the highest percentage was 61% to ph 7.5 with 15 hours of contact. In a contact time of 5 hours the extraction was inferior to 32% (ph 4) and of 47% to ph 6.5. The europium effect (Eu (III)) was studied to ph acid in the tyrosine separation and was found that the tyrosine extraction is not increased neither decomposes in europium presence, this is simultaneously extracted by the calixarene but it does not enter in competition for the calixarene with the amino acid. The separate solid phases: calixarene-tyrosine was analyzed by Far infrared radiation (Fir), Mid-Infrared (Mir) spectroscopy and luminescence to check the tyrosine presence in the separate solids as well as the nature of the connection calixarene-tyrosine. In this way was possible to check the tyrosine presence and to propose the formed molecular species tyrosine-calixarene, those which interact mainly by means of hydrogen connections and Van der Waals forces. The liquid phases before and after the extraction were analyzed by UV-Vis spectrophotometry and luminescence. The Neutron activation analysis was used to determine the europium content in the solid and liquid phases of extractions in europium presence. The tyrosine degradation also shows dependence with the ph, obtaining 88% degradation to the 24 hours to ph 7.5, while to ph 3 is degraded the 54% of tyrosine present in the sample. The europium presence does not affect the tyrosine extraction

  7. Calix[4]arene-phosphine dimers: precursors of flexible metallo-capsules and self-compacting molecules.

    Science.gov (United States)

    Sameni, Soheila; Jeunesse, Catherine; Matt, Dominique; Toupet, Loïc

    2009-10-12

    The first diphosphines based on a double calixarene, namely 1,4 (or 1,3)-bis-(5-diphenylphosphino-25,26,27,28-tetrapropoxycalix[4]aren-17-yl)benzene (L(2), L(3)) were each prepared in four steps starting from 5,17-dibromo-25,26,27,28-tetrapropoxycalix[4]arene. Upon reaction of L(2) with [Au(tht)(thf)]BF(4), (tht = C(4)H(8)S) a rigid metallo-capsule was quantitatively formed, which adopts an oblique form owing to the distinct nature of the spacers linking the two calixarene half-spheres. In the solid state, the 1,4-substituted phenylene linker is turned towards the gold ion, suggesting the existence of weak bonding interactions between two aromatic CH protons of this ring and the metal centre (AuH =2.67 A). In contrast to this gold complex, the related silver complex shows dynamic behaviour in solution, the exchange between two enantiomeric oblique forms being facilitated by the greater stereochemical flexibility of Ag(I) vs. Au(I). A heteronuclear (109)Ag{(1)H} HMQC experiment established strong correlations between the CH protons of the phenylene linker and the (109)Ag ion. Dynamic behaviour similar to that observed for the silver complex was further observed in trans-[PtCl(2)L(2)], a chelate complex that could be obtained quantitatively from L(2) and [PtCl(2)(PhCN)(2)]. The intended formation of a chelate complex leading to a capsule with an endo-oriented metal centre was achieved by reacting L(3) with [Pd(allyl)(thf)(2)]BF(4). The complex thus formed constitutes the first organometallic transition metal complex embedded in a cavity with large portals. Binding of [RuCl(2)(p-cymene)] to L(2) and L(3) resulted in self-compacting bimetallic complexes in which each calixarene basket entraps a Ru(p-cymene) unit, thereby forming molecules occupying a minimal volume.

  8. Allosteric tuning of the intra-cavity binding properties of a calix[6]arene through external binding to a ZnII center coordinated to amino side chains.

    Science.gov (United States)

    Darbost, Ulrich; Sénèque, Olivier; Li, Yun; Bertho, Gildas; Marrot, Jérôme; Rager, Marie-Noëlle; Reinaud, Olivia; Jabin, Ivan

    2007-01-01

    Molecular recognition by calix[6]arene-based receptors bearing three primary alkylamino side chain arms (1) is described. Complexation of Zn(II) ion provides the dinuclear mu-hydroxo complex 2G(OH), XRD characterization of which, together with solution studies, provided evidence of its hosting of neutral polar organic guests G. Treatment of this complex with a carboxylic acid or a sulfonamide (XH) results in the formation of mononuclear species 3G(X), one of which (X = Cl) has been characterized by XRD. A dicationic complex 3G(RNH2) is obtained upon treatment of 2G(OH) with a mixture of an alkylamine and a strong acid. Each of these Zn(II) complexes features a tetrahedral metal ion bound to the three amino arms of ligand 1 and to an exogenous ligand (either HO-, X-, or RNH2) sitting outside of the cavity. As a result, the metal ion structures the calixarene core, constraining it in a cone conformation suitable for guest hosting. The receptor properties of these compounds have been explored in detail and are compared with those of the trisammonium receptor 1G(3H+), based on the same calixarene core, as well as those of the trisimidazole-based dicationic Zn funnel complexes. This study reveals very different host properties, in spite of the common hydrophobic, pi-basic, and hydrogen-bonding acceptor properties of the calixarene cores. A harder external ligand produces a less polarized receptor that is consequently particularly sensitive to the hydrogen-bonding ability of its guest. The less electron-rich the apical ligand, and a fortiori the trisammonium host, the more sensitive the receptor to the dipole moment of the guest. All this stands in contrast with the funnel Zn complexes, in which the coordination link plays a dominant role. It is also shown that the asymmetry of an exo-coordinated enantiopure amino ligand is sensed by the guest. This supramolecular system nicely illustrates how the receptor properties of a hydrophobic cavity can be allosterically tuned by

  9. Biphen[n]arenes† †Electronic supplementary information (ESI) available: Detailed synthetic procedures and characterization, crystal data for EtBP3 and EtBP4, ESI spectra, additional 1H NMR spectra, Job plots, and determination of the association constants. CCDC 1016929 and 1016930. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4sc02422b Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

    Chen, Huanqing; Fan, Jiazeng; Hu, Xiaoshi; Ma, Junwei; Wang, Shilu; Li, Jian; Yu, Yihua; Jia, Xueshun

    2015-01-01

    To design and exploit novel macrocyclic synthetic receptors is a permanent and challenging topic in supramolecular chemistry. Here we describe the one-pot synthesis, unique geometries and intriguing host–guest properties of a new class of supramolecular macrocycles – biphen[n]arenes (n = 3, 4), which are made up of 4,4′-biphenol or 4,4′-biphenol ether units linked by methylene bridges at the 3- and 3′- positions. The biphenarene macrocycles are conveniently accessible/modifiable and extremely guest-friendly. Particularly, biphen[4]arene is capable of forming inclusion complexes with not only organic cationic guests but also neutral π-electron deficient molecules. Compared with calixarenes, resorcinarenes, cyclotriveratrylenes and pillararenes with substituted mono-benzene units, the biphen[n]arenes reported here possess significantly different characteristics in both their topologic structures and their recognition properties, and thus can find broad applications in supramolecular chemistry and other areas. PMID:28553468

  10. FULERENIC MATERIALS WITH BIOMEDICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Radu Claudiu FIERASCU

    2010-05-01

    Full Text Available Soluble fullerenic derivates are essential for numerous biomedical techniques that exploit the unique structural chemical and physical properties of carbon nanospheres. Their toxicity, demonstrated in vitro and in vivo is important for the characterization and limitation of those applications. The phototoxicity of some fullerene molecules was identified as a future therapeutical instrument. Other studies focused on the decrease of the phototoxicity of hydrosoluble fullerenes follow the use of those compounds as drug delivery systems or their use in environment protection. Starting from the characteristics of those compounds, which can be by themeselves cytotoxic, or could become during irradiation (photosensitizers we have tried to obtain new materials based on fullerenes and diads/triads fullerene/porphyrines or fullerenes/calixarenes.The obtained complexes were characterized by UV Vis and IR spectroscopy.

  11. Biphen[n]arenes.

    Science.gov (United States)

    Chen, Huanqing; Fan, Jiazeng; Hu, Xiaoshi; Ma, Junwei; Wang, Shilu; Li, Jian; Yu, Yihua; Jia, Xueshun; Li, Chunju

    2015-01-01

    To design and exploit novel macrocyclic synthetic receptors is a permanent and challenging topic in supramolecular chemistry. Here we describe the one-pot synthesis, unique geometries and intriguing host-guest properties of a new class of supramolecular macrocycles - biphen[n]arenes (n = 3, 4), which are made up of 4,4'-biphenol or 4,4'-biphenol ether units linked by methylene bridges at the 3- and 3'- positions. The biphenarene macrocycles are conveniently accessible/modifiable and extremely guest-friendly. Particularly, biphen[4]arene is capable of forming inclusion complexes with not only organic cationic guests but also neutral π-electron deficient molecules. Compared with calixarenes, resorcinarenes, cyclotriveratrylenes and pillararenes with substituted mono-benzene units, the biphen[n]arenes reported here possess significantly different characteristics in both their topologic structures and their recognition properties, and thus can find broad applications in supramolecular chemistry and other areas.

  12. Characteristics of a novel calix[8]arene modified with carbon nanotubes thin films for metal cations detection

    Science.gov (United States)

    Supian, Faridah Lisa; Bakar, Suriani Abu; Azahari, Noor Azyyati; Richardson, Tim H.

    2013-05-01

    This study focuses on the properties of a novel calix[8]arene that have been modified with carbon nanotubes (CNT) as ion sensor application. Calix[8]arene modified with carbon nanotubes were done by mixing CNT (Calix8A-CNT) with a novel calix[8]arene in a long ultrasonication process. This study is interesting due to the process on the attaching of the functionalization of the calixarene on the carbon nanotubes outer wall. Morphological and spectroscopic studies of Calix8A-CNT were done using Π-A isotherm, Surface Potential Probe (S-Pot), Field mission scanning electron microscopy (FE-SEM) and Raman spectroscopy in order to understand the behavior in the molecular level. This water-soluble supramolecular hybrid materials have potential as metal cations detection and nanoelectronics applications, yet the CNT provide the thermal stability to the polymers.

  13. Recyclable calix[4]arene-lanthanoid luminescent hybrid materials with color-tuning and color-switching properties.

    Science.gov (United States)

    Ennis, Brendan W; Muzzioli, Sara; Reid, Brodie L; D'Alessio, Daniel M; Stagni, Stefano; Brown, David H; Ogden, Mark I; Massi, Massimiliano

    2013-05-21

    Inorganic-organic hybrid materials combine the properties of both components providing functionality with a wide range of potential applications. Phase segregation of the inorganic and organic components is a common challenge in these systems, which is overcome here by copolymerizing a metal-free calixarene ionophore and methyl methacrylate. A lanthanoid ion is then added using a swelling-deswelling procedure. The resulting luminescent hybrid materials can be made to emit any required color, including white light, by loading with an appropriate mixture of lanthanoids. The gradation of the emitted color can also be finely adjusted by changing the excitation wavelength. The polymer monolith can be recycled to emit a different color by swelling with a solution containing a different lanthanoid ion. This methodology is flexible and has the potential to be extended to many different ionophores and polymer matrices.

  14. Playing with podands based on cone-shaped cavities. How can a cavity influence the properties of an appended metal centre?

    Science.gov (United States)

    Jeunesse, Catherine; Armspach, Dominique; Matt, Dominique

    2005-12-07

    The potential of molecules that combine the properties of a conical cavity with those of a covalently-linked transition-metal centre is highlighted through the assessment of cyclodextrin- and calixarene-derived podands ("cavitand" ligands) in coordination chemistry and catalysis. Metallocavitands with coordination sites directed towards the interior of the generic cavity provide interesting systems for studying host-guest complexation processes, their enhanced strength of metal-ion binding allowing for regioselective catalysis in a confined environment, and stabilisation of coordination complexes of unusual forms. Where cavitands have exo-oriented podand arms, the intrinsic dynamics of the cavity can dramatically modify metal chelation behaviour and the catalytic properties of the complexes. Such functionalised cavities are also useful as metal-ion transporters.

  15. Computational study of small molecule binding for both tethered and free conditions.

    Science.gov (United States)

    Ytreberg, F Marty

    2010-04-29

    Using a calix[4]arene-benzene complex as a test system, we compare the potential of mean force for when the calix[4]arene is tethered versus free. When the complex is in vacuum, our results show that the difference between tethered and free is primarily due to the entropic contribution to the potential of mean force resulting in a significant binding free energy difference of 6.6 kJ/mol. By contrast, when the complex is in water, our results suggest that there is no appreciable difference between tethered and free. This study elucidates the roles of entropy and enthalpy for this small molecule system and emphasizes the point that tethering the receptor has the potential to dramatically impact the binding properties. These findings should be taken into consideration when using calixarene molecules in nanosensor design.

  16. Gamma Ray Radiolysis of the FPEX Solvent

    Energy Technology Data Exchange (ETDEWEB)

    B. J. Mincher; S. P. Mezyk; D. R. Peterman

    2006-09-01

    Slide presentation. FPEX contains a calixarene for Cs extraction, a crown ether for Sr extraction, Cs7SB modifier, and TOA to aid in stripping, in Isopar L diluent. The radiation stability FPEX must be evaluated prior to process use. Radiolytic degradation of species in solution are due to reaction with the direct radiolysis products of the diluent. In Isopar L, the reactive species produced include e-, •H and alkane radicals, resulting in a reducing environment. However, in nitric acid, oxidizing hydroxyl (•OH) and nitro (•NO2) radicals dominate system chemistry. Thus, the nature of diluent and the presence of radical scavengers affect the results of irradiation. We report the preliminary results of a new program to investigate the radiolysis of FPEX using the 60Co irradiation of FPEX neat solvent, acid pre-equilibrated solvent and mixed aerated phases. The Cs and Sr distribution ratios were used as metrics.

  17. 81929 - Fission-Product Separation Based on Room - Temperature Ionic Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Robin D. Rogers

    2004-12-09

    This project has demonstrated that Sr2+ and Cs+ can be selectively extracted from aqueous solutions into ionic liquids using crown ethers and that unprecedented large distribution coefficients can be achieved for these fission products. The volume of secondary wastes can be significantly minimized with this new separation technology. Through the current EMSP funding, the solvent extraction technology based on ionic liquids has been shown to be viable and can potentially provide the most efficient separation of problematic fission products from high level wastes. The key results from the current funding period are the development of highly selective extraction process for cesium ions based on crown ethers and calixarenes, optimization of selectivities of extractants via systematic change of ionic liquids, and investigation of task-specific ionic liquids incorporating both complexant and solvent characteristics.

  18. Structural, mechanical, and electronic properties of novel thiophene-based electroactive materials and devices from first-principles

    Science.gov (United States)

    Scherlis, Damian; Swager, Timothy; Hunter, Ian; Marzari, Nicola

    2004-03-01

    The properties of a novel class of thiophene-based electroactuating polymers are explored using a combination of first-principles molecular dynamics and high-level quantum chemistry approaches. Electronic-structure simulations highlight the role that passive mechanical components (such as calixarene crowns) and electroactive components (oligothiophenes) have in determining the response properties of the material. Accurate, correlated-electron descriptions of the ground state were needed in view of the wide discrepancies between DFT results at the LDA and GGA level. Our calculations provide quantitative insight in the actuation mechanism following oxidation, and in the role of different charged states and solvation environments in determining stability, stacking, and actuating strength. Such microscopic understanding is essential in the design and improvement of thiophene-based nanodevices, and can lead to the proposal of novel active molecular architectures.

  19. A bioinspired approach for controlling accessibility in calix[4]arene-bound metal cluster catalysts

    Science.gov (United States)

    de Silva, Namal; Ha, Jeong-Myeong; Solovyov, Andrew; Nigra, Michael M.; Ogino, Isao; Yeh, Sheila W.; Durkin, Kathleen A.; Katz, Alexander

    2010-12-01

    In enzymes, the electronic and steric environments of active centres, and therefore their activity in biological processes, are controlled by the surrounding amino acids. In a similar manner, organic ligands have been used for the `passivation' of metal clusters, that is, inhibition of their aggregation and control of their environment. However, the ability of enzymes to maintain large degrees of accessibility has remained difficult to mimic in synthetic systems in which little room, if any, is typically left to bind to other species. Here, using calix[4]arene macrocycles bearing phosphines as crude mimics of the rigid backbones of proteins, we demonstrate the synthesis of gold clusters and the control of their accessibility through an interplay between the sizes of the calixarene ligands and metal cores. For 0.9-nm cores, 25% of all the gold atoms within the cluster bind to the chemisorption probe 2-naphthalenethiol. This accessibility dramatically decreases with 1.1-nm and 4-nm gold cores.

  20. Temperature-regulated guest admission and release in microporous materials

    Science.gov (United States)

    Li, Gang (Kevin); Shang, Jin; Gu, Qinfen; Awati, Rohan V.; Jensen, Nathan; Grant, Andrew; Zhang, Xueying; Sholl, David S.; Liu, Jefferson Z.; Webley, Paul A.; May, Eric F.

    2017-06-01

    While it has long been known that some highly adsorbing microporous materials suddenly become inaccessible to guest molecules below certain temperatures, previous attempts to explain this phenomenon have failed. Here we show that this anomalous sorption behaviour is a temperature-regulated guest admission process, where the pore-keeping group's thermal fluctuations are influenced by interactions with guest molecules. A physical model is presented to explain the atomic-level chemistry and structure of these thermally regulated micropores, which is crucial to systematic engineering of new functional materials such as tunable molecular sieves, gated membranes and controlled-release nanocontainers. The model was validated experimentally with H2, N2, Ar and CH4 on three classes of microporous materials: trapdoor zeolites, supramolecular host calixarenes and metal-organic frameworks. We demonstrate how temperature can be exploited to achieve appreciable hydrogen and methane storage in such materials without sustained pressure. These findings also open new avenues for gas sensing and isotope separation.

  1. Magnetoresistance oscillations of two-dimensional electron systems in lateral superlattices with structured unit cells

    Science.gov (United States)

    Gerhardts, Rolf R.

    2015-11-01

    Model calculations for commensurability oscillations of the low-field magnetoresistance of two-dimensional electron systems (2DES) in lateral superlattices, consisting of unit cells with an internal structure, are compared with recent experiments. The relevant harmonics of the effective modulation potential depend not only on the geometrical structure of the modulated unit cell, but also strongly on the nature of the modulation. While higher harmonics of an electrostatically generated surface modulation are exponentially damped at the position of the 2DES about 90 nm below the surface, no such damping appears for strain-induced modulation generated, e.g., by the deposition of stripes of calixarene resist on the surface before cooling down the sample.

  2. Molecular engineering and fluorescence for the detection of toxic cations; Ingenierie moleculaire et fluorescence pour la reconnaissance de cations toxiques

    Energy Technology Data Exchange (ETDEWEB)

    Souchon, V

    2007-11-15

    This work is a part of the 'Toxicologie Nucleaire Environnementale' program which aims at studying the effects on the living of heavy metals or radionuclides involved in nuclear industry. Most particularly, it deals with the design of new fluorescent sensors for the selective detection of Pb{sup 2+}, Cd{sup 2+} and Cs{sup +} in biological media. Several fluorescent calixarenes possessing nitrogen atoms were synthesized and their properties as potential lead sensors were investigated. One of them could be used in experimental conditions close to biological media and new target compounds with amide functional groups were proposed. Many approaches were considered for the design of selective fluorescent sensors for cadmium. On the basis of literature results, many chelating compounds incorporating sulfur atoms were synthesized but showed no significant affinity towards cadmium. On the opposite, compounds functionalized with several pyridine-2'-yl-1,2,3-triazol fluorescent moieties linked to a {beta}-cyclodextrin or a calix[4]arene showed good affinity for cadmium in methanol, but the selectivity was found to be insufficient. In contrast, very satisfying results in terms of both selectivity and sensitivity could be obtained with the commercial calcium sensor Rhod-5N in an aqueous medium at neutral pH. Lastly, micromolar detection limits for the selective detection of caesium were reached in an aqueous medium at neutral pH thanks to a new sulfonated fluorescent calixarene with two appended crown-ethers. An original complexation mechanism was proposed and validated by molecular modelling (DFT). (author)

  3. In situ formation of silver nanoparticle layer by supramolecule-directed assembly

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ruitao, E-mail: g0701276@nus.edu.sg; Teo, Shileng, E-mail: attenzion@hotmail.com; Srinivasan, M.P., E-mail: srinivasan.mp@nus.edu.sg

    2014-01-01

    We report an in situ synthesis route for preparation of a layer of AgNPs (silver nanoparticles) on the silicon surface by employing an immobilized supramolecular layer as a directing agent. The AgNPs were immobilized and stabilized by a calix[7]hydroquinone monolayer which in turn was immobilized on the silicon surface by covalent layer-by-layer assembly. The calix[7]hydroquinone moiety served as a nano-reactor, container and template in the in situ synthesis process. AgNPs were formed by reduction of Ag ions by the hydroquinone form of the calix[7]arene. The AgNPs were obtained as plate-shaped particles with a diameter of about 10 nm and a height of less than 2 nm, and were stabilized and wrapped by calix[7]arene molecules. By repeated application of the redox properties of calix[7]arene, the size of the AgNPs can be adjusted continuously up to islands of 100 nm or larger. The process of in situ synthesis under controlled conditions, together with calibrated variation of particle size has the potential to serve as building blocks for electronic nano-devices. A significant advantage derived by this method of formation and assembly is its surfactant-free nature that enables access to the active surface of the nanoparticle. - Highlights: • 4-Methoxycalix[7]arene synthesized as a pure product • 4-Methoxycalix[7]arene immobilized by covalent bonding • In situ synthesis of Ag nanoparticles on the surface of the calixarene monolayer • Repeated redox process for forming Ag nanoparticles on the calixarene surface.

  4. Molecular Assemblies of Porphyrins and Macrocyclic Receptors: Recent Developments in Their Synthesis and Applications

    Directory of Open Access Journals (Sweden)

    Abdirahman A. Mohamod

    2012-10-01

    Full Text Available Metalloporphyrins which form the core of many bioenzymes and natural light harvesting or electron transport systems, exhibit a variety of selective functional properties depending on the state and surroundings with which they exist in biological systems. The specificity and ease with which they function in each of their bio-functions appear to be largely governed by the nature and disposition of the protein globule around the porphyrin reaction center. Synthetic porphyrin frameworks confined within or around a pre-organized molecular entity like the protein network in natural systems have attracted considerable attraction, especially in the field of biomimetic reactions. At the same time a large number of macrocyclic oligomers such as calixarenes, resorcinarenes, spherands, cyclodextrins and crown ethers have been investigated in detail as efficient molecular receptors. These molecular receptors are synthetic host molecules with enclosed interiors, which are designed three dimensionally to ensure strong and precise molecular encapsulation/recognition. Due to their complex structures, enclosed guest molecules reside in an environment isolated from the outside and as a consequence, physical properties and chemical reactions specific to that environment in these guest species can be identified. The facile incorporation of such molecular receptors into the highly photoactive and catalytically efficient porphyrin framework allows for convenient design of useful molecular systems with unique structural and functional properties. Such systems have provided over the years attractive model systems for the study of various biological and chemical processes, and the design of new materials and molecular devices. This review focuses on the recent developments in the synthesis of porphyrin assemblies associated with cyclodextrins, calixarenes and resorcinarenes and their potential applications in the fields of molecular encapsulation/recognition, and

  5. Biomimetic zinc funnel complexes based on calix[6]N3ArO ligands: an acid-base switch for guest binding.

    Science.gov (United States)

    Sénèque, Olivier; Rager, Marie-Noëlle; Giorgi, Michel; Prangé, Thierry; Tomas, Alain; Reinaud, Olivia

    2005-10-26

    The coordination chemistry of Zn in an N(3)ArOH environment has been explored. The ligands are based on calix[6]arenes that present two imidazole arms and an amino phenol moiety at the narrow rim. Three different types of complexes have been characterized. One is dicationic with Zn(2+) coordinated to the three nitrogen atoms and to the oxygen of the phenol group of the calix[6]ligand. This complex is very sensitive to exogenous coordinating molecules and exists as a 5-coordinate species due to the endo-complexation of a guest. The second species is a monocationic complex for which the phenol group has been deprotonated. The resulting N(3)ArOZn complex can also bind a guest ligand albeit with a lower affinity than the dicationic complex. The third species is neutral. It can be obtained upon reaction with a base to yield a hydroxo complex or with an anion such as a chloride that coordinates the metal center from the outside of the calixarene cavity. The simultaneous binding of two anionic donors decreases the Zn Lewis acidity, allowing an impressive conformational reorganization of the system. One imidazole arm is released by the metal center. The other one undergoes self-inclusion into the pi-basic calixarene cavity because the low affinity of the metal center for neutral ligand does not allow the endo-coordination of an exogenous guest. Hence, the calix[6]N(3)ArOH-based Zn complexes act as an acid-base switch for guest binding. Several aspects of this system appear reminiscent of Zn-peptidases of the astacin and serralisin families.

  6. Binding properties of oxacalix[4]arenes derivatives toward metal cations; Interactions entre cations metalliques et derives des oxacalix[4]arenes

    Energy Technology Data Exchange (ETDEWEB)

    Mellah, B

    2006-11-15

    The objective of this work was to establish the binding properties of oxacalix[4]arene derivatives with different numbers of the oxa bridges, functional groups (ketones, pyridine, ester, amide and methoxy) and conformations. Their interactions with alkali and alkaline-earth, heavy and transition metal cations have been evaluated according to different approaches: (i) extraction of corresponding picrates from an aqueous phase into dichloromethane; (ii) determination of the thermodynamic parameters of complexation in methanol and/or acetonitrile by UV-spectrophotometry and micro-calorimetry; (iii) determination of the stoichiometry of the complexes by ESI-MS; (iv) {sup 1}H-NMR titrations allowing to localize the metal ions in the ligand cavity. In a first part dealing on homo-oxacalix[4]arenes, selectivities for Na{sup +}, K{sup +}, Ca{sup 2+}, Pb{sup 2+} and Mn{sup 2+} of ketones derivatives was shown. The presence of oxa bridge in these derivatives increases their efficiency while decreasing their selectivity with respect to related calixarenes. The pyridine derivative prefers transition and heavy metal cations, in agreement with the presence of the soft nitrogen atoms. In the second part, di-oxacalix[4]arene ester and secondary amide derivatives were shown to be less effective than tertiary amide counterparts but to present high selectivities for Li{sup +}, Ba{sup 2+}, Zn{sup 2+} and Hg{sup 2+}. A third part devoted to the octa-homo-tetra-oxacalix[4]arene tetra-methoxy shows that the 1:1 metal complexes formed are generally more stable than those of calixarenes, suggesting the participation of the oxygen atoms of the bridge in the complexation. Selectivity for Cs{sup +}, Ba{sup 2+}, Cu{sup 2+} and Hg{sup 2+} were noted. (author)

  7. Capability of parasulfonato calix[6]arene, as an anion dopant, and organic solvents in enhancing the sensitivity and loading of glucose oxidase (GOx) on polypyrrole film in a biosensor: a comparative study.

    Science.gov (United States)

    Safarnavadeh, Vahideh; Zare, Karim; Fakhari, Ali Reza

    2013-11-15

    In this study, the effects of two solvents (acetonitrile and water) and an anion dopant (para sulfonato calix[6]arene ((C[6]S)(-6))), on the manufacturing and properties of a polypyrrole (Ppy)-based, glucose oxidase amperometric biosensor were studied. Pyrrole was polymerized using galvanostatic mode in two different solvents, and the effect of (C[6]S)(-6) was studied in aqueous solution. The morphology of the obtained polypyrrole films was studied by scanning electron microscopy (SEM). Glucose oxidase (GOx) was adsorbed on the Ppy films via cross-linking method. Then the amperometric responses of the Pt/Ppy/GOx electrodes were measured using the amperometric method at the potential of 0.7 V in steps of adding a glucose solution to a potassium phosphate buffer. We found that acetonitrile and (C[6]S)(-6) increase the sensitivity of the enzyme electrode up to 79.30 µA M(-1)cm(-2) in comparison with 31.60 μA M(-1)cm(-2) for the electrode synthesized in calixarene free aqueous solvent. Also (C[6]S)(-6) has the main role in preventing leaching the enzyme from the electrode. This fact increases loading of the enzyme and stability of the biosensor. So that the steady state current density of the aforementioned electrode increases linearly with increasing glucose concentration up to 190 mM. Whereas the linearity was observed up to 61 mM and 80 mM for the electrodes made using calixarene free acetonitrile and aqueous solutions, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Quantum dot-dye hybrid systems for energy transfer applications

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Ting

    2010-07-01

    -dye complexes can also be easily transferred into water. Our approach can apply to not only dye molecules but also other organic molecules. As an example, the QDs have been complexed with calixarene molecules and the QD-calixarene complexes also have potential for QD-based energy transfer study. (orig.)

  9. Theoretical modelling of tripodal CuN3 and CuN4 cuprous complexes interacting with O2, CO or CH3CN.

    Science.gov (United States)

    de la Lande, Aurélien; Gérard, Hélène; Moliner, Vicent; Izzet, Guillaume; Reinaud, Olivia; Parisel, Olivier

    2006-07-01

    Dioxygen binding at copper enzymatic sites is a fundamental aspect of the catalytic activity observed in many biological systems such as the monooxygenases, especially peptidylglycine alpha-hydroxylating monooxygenase (PHM), in which two mononuclear Cu(I) sites are involved. Biomimetic models have been developed: dipods, tripods, and, more recently, functionalized calixarenes. The modelling of calixarene systems, although not unreachable for theory yet, requires, however, a number of preliminary investigations to ensure proper calibrations if relevant description of the metal-ligand interaction at the hybrid quantum mechanical/molecular mechanics levels of theory is the aim. In this paper, we report quantum chemistry investigations on a coherent series of representative cuprous tripodal species characterized by (1) monodentate ligands [Cu(ImH)3]+ (where ImH is imidazole), [Cu(MeNH2)3]+ and [Cu(MeNH2)4]+ , (2) neutral tripodal ligands [CuCH(ImH)3]+, [Cu(tren)]+ [where tren is tris(2-aminoethyl)amine], and [Cu(trenMe3)]+ [where trenMe3 is tris(2-methylaminoethyl)amine] and (3) a hydrido-tris(pyrazolyl)borate [CuBH(Pyra)3]. The structures of these complexes, the coordination mode (eta(2) side-on or eta(1) end-on) of O2 to Cu(I) and the charge transfer from the metal to dioxygen have been computed. For some systems, the coordination by CH3CN and CO is also reported. Beyond results relative to structural properties, an interesting feature is that it is possible to build from computational results only a set of abacuses linking the nu(16O-16O) vibrational frequency of the coordinated O2 molecule to the O-O bond length or to the net charge of the O2 moiety. Such abacuses may help experimentalists in distinguishing between the four possible ways of binding O2 to CuN3 and CuN4 cuprous centres, namely (1) end-on triplet states, (2) side-on triplet states, (3) end-on singlet states and (4) side-on singlet states. These abacuses are extended to three tripods obtained by the

  10. Calix[4]arenes with one and two N-linked imidazolium units as precursors of N-heterocyclic carbene complexes. Coordination chemistry and use in Suzuki-Miyaura cross-coupling.

    Science.gov (United States)

    Brenner, Eric; Matt, Dominique; Henrion, Mickaël; Teci, Matthieu; Toupet, Loïc

    2011-10-14

    The calix[4]arene-imidazolium salts 5-(3-butyl-1-imidazolylium)-25,26,27,28-tetrabenzyloxy-calix[4]arene bromide (cone) (2), and 5,11-bis(3-alkyl-1-imidazolylium)-25,26,27,28-tetrabenzyloxycalix[4]arene diiodide (cone) (R = methyl, 3a; R = n-butyl, 3b) have been synthesised. Reaction of 2 in dioxane with PdCl(2) in the presence of CsCO(3) and KBr (80 °C, 24 h) gives the carbene complex trans-[PdBr(2)(calix-monocarbene)(2)] (14), containing two N-heterocyclic carbene ligands derived from 2 (yield: 63%). Repeating the reaction in pyridine instead of dioxane gives the mixed pyridine-carbene complex trans-[PdBr(2)(calix-carbene)(pyridine)] (15) in 75% yield. Treatment of the bis-imidazolium salt 3a with [Pd(OAc)(2)] affords a chelate complex, trans-[PdI(2){calix-bis(carbene)}] (16), in which a metallo-(bis-carbene) fragment caps the upper rim of the calixarene basket. Complex 16, as well as its analogue 17, obtained from 3b, display apparent C(s)-symmetry in solution. This is not the case in the solid state, a single X-ray diffraction study carried out for 16 revealing a pinced cone structure for the calixarene skeleton, which reduces the symmetry to C(1). The chelate complex 17 shows poor activity in Suzuki-Miyaura cross-coupling of phenyl boronic acid and p-tolyl halides, an observation that suggests the presence of a strained metallocyclic unit preventing easy stereochemical rearrangement to an active species. Unlike 17, complexes 14 and 15 show good activities in cross-coupling. A comparative study using the carbene precursor 1-butyl-3-(2,6-diisopropylphenyl)imidazolium bromide (18), which is devoid of the receptor fragment, strongly suggests that the carbene ligands of 14 and 15 operate typically as bulky NHC-ligands.

  11. New polymeric membrane cadmium(II)-selective electrodes using tripodal amine based ionophores

    Energy Technology Data Exchange (ETDEWEB)

    Khamjumphol, Utisawadee [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Watchasit, Sarayut [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Suksai, Chomchai [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Burapha University, Chonburi 20131 (Thailand); Janrungroatsakul, Wanwisa [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Boonchiangma, Suthasinee [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Tuntulani, Thawatchai [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Ngeontae, Wittaya, E-mail: wittayange@kku.ac.th [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Research Center for Environmental and Hazardous Substance Management, Khon Kaen University, Khon Kaen 40002 (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management, Khon Kaen University, Khon Kaen 40002 (Thailand)

    2011-10-17

    Highlights: {yields} New four ionophores having tripodal amine (TPA) unit on anthracene and calixarene. {yields} Synthesis and characterization data were reported. {yields} Incorporated to the plasticized PVC membranes to prepare Cd-ISEs. {yields} Two TPA units on calixarene showed the best selectivity toward Cd{sup 2+}. {yields} Applied for sensing Cd{sup 2+} from the oxidation of CdS QDs solution. - Abstract: Fabrication of PVC membrane electrodes incorporating selective neutral carriers for Cd{sup 2+} was reported. The ionophores were designed to have different topologies, donor atoms and lipophilicity by attaching tripodal amine (TPA) units to the lipophilic anthracene (ionophore I) and p-tert-butylcalix[4]arene (ionophores II, III and IV). The synthesized ionophores were incorporated to the plasticized PVC membranes to prepare Cd(II) ion selective electrodes (ISEs). The membrane electrodes were optimized by changing types and amounts of ionic sites and plasticizers. The selectivity of the membranes fabricated from the synthesized ionophores was evaluated, the relationship between structures of ionophores and membrane characteristics were explored. The ionophore IV which composed of two opposites TPA units on the calix[4]arene compartment showed the best selectivity toward Cd{sup 2+}. The best membrane electrode was fabricated from ionophore IV (10.2 mmol kg{sup -1}) with KTpClPB (50.1 mol% related to the ionophore) as an ion exchanger incorporated in the DOS plasticized PVC membrane (1:2; PVC:DOS). The Cd-ISE fabricated from ionophore IV exhibited good properties with a Nernstian response of 29.4 {+-} 0.6 mV decade{sup -1} of activity for Cd{sup 2+} ions and a working concentration range of 1.6 x 10{sup -6}-1.0 x 10{sup -2} M. The sensor has a fast response time of 10 s and can be used for at least 1 week without any divergence in potential. The electrode can be used in the pH range of 6.0-9.0. The proposed electrodes using ionophores III and IV were employed

  12. Synthesis and complexation properties towards uranyl cation of carboxylic acid derivatives of p-tert-butyl-calix[6]arene; Synthese et proprietes complexantes vis-a-vis de l'ion uranyle de derives carboxyliques du p-tert-butyl-calix[6]arene

    Energy Technology Data Exchange (ETDEWEB)

    Souane, R

    2005-03-15

    In the fuel reprocessing plants radioactive metals, and more particularly, uranium in UO{sub 2}{sup 2+} form in the various installations, have many varied physico-chemical forms and there is a risk of exposure and internal contamination in the nuclear industry. It is necessary to exert a medical control to ensure the protection of the health of the workers. This medical control is done by dosing uranyl cation in the urine of the exposed people. This work forms part of this context. Indeed, we prepared a ligand able to complex the ion uranyl and which is also to be grafted on a solid support. In the family of calixarenes, the calix[6]arenes functionalized by three or four carboxylic functions were selected like chelating molecules of the ion uranyl. The properties of complexation of these calixarenes were studied by potentiometry in methanol, under these conditions balances of protonation and complexation were determined and the constant partners were obtained using the Hyperquad program. We synthesized tri-carboxylic calix[6]arenes comprising of the groupings nitro (NO{sub 2}) in para position of phenol in order to see the influence of a substitution in para position on the complexation. We also synthesized calix[6]arenes tetra-carboxylic in order to show the role of an additional carboxylic acid grouping. The potentiometric study determined thermodynamic parameters of protonation and complexation of carboxylic calix[6]arenes. The results of the complexation highlighted which complex UO{sub 2}L corresponding to the ligand para-tert-butyl-calix[6]arene tetra-acid is more stable than that corresponding to the ligand mono-nitro calix[6]arene tri-acid ({delta}log{beta}110 = 4.3), and than the effect of the groupings nitro in para position has low influence on the complexation of UO{sub 2}{sup 2+}. This makes it possible to consider as possible the grafting of the calix[6]arenes which one knows the behaviour of trapping. To this end we synthesized the ligand 23

  13. Fluorescence Resonance Energy Transfer Systems in Supramolecular Macrocyclic Chemistry.

    Science.gov (United States)

    Lou, Xin-Yue; Song, Nan; Yang, Ying-Wei

    2017-09-29

    The fabrication of smart materials is gradually becoming a research focus in nanotechnology and materials science. An important criterion of smart materials is the capacity of stimuli-responsiveness, while another lies in selective recognition. Accordingly, supramolecular host-guest chemistry has proven a promising support for building intelligent, responsive systems; hence, synthetic macrocyclic hosts, such as calixarenes, cucurbiturils, cyclodextrins, and pillararenes, have been used as ideal building blocks. Meanwhile, manipulating and harnessing light artificially is always an intensive attempt for scientists in order to meet the urgent demands of technological developments. Fluorescence resonance energy transfer (FRET), known as a well-studied luminescent activity and also a powerful tool in spectroscopic area, has been investigated from various facets, of which the application range has been broadly expanded. In this review, the innovative collaboration between FRET and supramolecular macrocyclic chemistry will be presented and depicted with typical examples. Facilitated by the dynamic features of supramolecular macrocyclic motifs, a large variety of FRET systems have been designed and organized, resulting in promising optical materials with potential for applications in protein assembly, enzyme assays, diagnosis, drug delivery monitoring, sensing, photosynthesis mimicking and chemical encryption.

  14. Fluorescence Resonance Energy Transfer Systems in Supramolecular Macrocyclic Chemistry

    Directory of Open Access Journals (Sweden)

    Xin-Yue Lou

    2017-09-01

    Full Text Available The fabrication of smart materials is gradually becoming a research focus in nanotechnology and materials science. An important criterion of smart materials is the capacity of stimuli-responsiveness, while another lies in selective recognition. Accordingly, supramolecular host-guest chemistry has proven a promising support for building intelligent, responsive systems; hence, synthetic macrocyclic hosts, such as calixarenes, cucurbiturils, cyclodextrins, and pillararenes, have been used as ideal building blocks. Meanwhile, manipulating and harnessing light artificially is always an intensive attempt for scientists in order to meet the urgent demands of technological developments. Fluorescence resonance energy transfer (FRET, known as a well-studied luminescent activity and also a powerful tool in spectroscopic area, has been investigated from various facets, of which the application range has been broadly expanded. In this review, the innovative collaboration between FRET and supramolecular macrocyclic chemistry will be presented and depicted with typical examples. Facilitated by the dynamic features of supramolecular macrocyclic motifs, a large variety of FRET systems have been designed and organized, resulting in promising optical materials with potential for applications in protein assembly, enzyme assays, diagnosis, drug delivery monitoring, sensing, photosynthesis mimicking and chemical encryption.

  15. Advanced electric-field scanning probe lithography on molecular resist using active cantilever

    Science.gov (United States)

    Kaestner, Marcus; Aydogan, Cemal; Ivanov, Tzvetan; Ahmad, Ahmad; Angelov, Tihomir; Reum, Alexander; Ishchuk, Valentyn; Krivoshapkina, Yana; Hofer, Manuel; Lenk, Steve; Atanasov, Ivaylo; Holz, Mathias; Rangelow, Ivo W.

    2015-07-01

    The routine "on demand" fabrication of features smaller than 10 nm opens up new possibilities for the realization of many devices. Driven by the thermally actuated piezoresistive cantilever technology, we have developed a prototype of a scanning probe lithography (SPL) platform which is able to image, inspect, align, and pattern features down to the single digit nanoregime. Here, we present examples of practical applications of the previously published electric-field based current-controlled scanning probe lithography. In particular, individual patterning tests are carried out on calixarene by using our developed table-top SPL system. We have demonstrated the application of a step-and-repeat SPL method including optical as well as atomic force microscopy-based navigation and alignment. The closed-loop lithography scheme was applied to sequentially write positive and negative tone features. Due to the integrated unique combination of read-write cycling, each single feature is aligned separately with the highest precision and inspected after patterning. This routine was applied to create a pattern step by step. Finally, we have demonstrated the patterning over larger areas, over existing topography, and the practical applicability of the SPL processes for lithography down to 13-nm pitch patterns. To enhance the throughput capability variable beam diameter electric field, current-controlled SPL is briefly discussed.

  16. Novel cinchona carbamate selectors with complementary enantioseparation characteristics for N-acylated amino acids.

    Science.gov (United States)

    Krawinkler, Karl Heinz; Maier, Norbert M; Ungaro, Rocco; Sansone, Francesco; Casnati, Alessandro; Lindner, Wolfgang

    2003-01-01

    The synthesis and chromatographic evaluation of the enantiomer separation capabilities of covalently immobilized calix[4]arene-cinchona carbamate hybrid type receptors derived from quinine (QN) and its corresponding C9-epimer (eQN) in different solvents are reported. The receptors display complementary enantiomer separation profiles in terms of elution order, chiral substrate specificity, and mobile phase characteristics, indicating the existence of two distinct chiral recognition mechanisms. The QN-derived receptor binds the (S)-enantiomers of N-acylated amino acids more strongly, shows preferential recognition of open-chained amino acids, and superior enantioselectivity in polar media such as methanol/acetic acid. In contrast, the eQN congener preferentially recognizes the corresponding (R)-enantiomers, displays good enantioselectivity (alpha up to 1.74) for cyclic amino acids, and enhanced stereodiscriminating properties in apolar mobile phases, e.g., chloroform/acetic acid. A comparison of the enantiomer separation profiles with those of the corresponding QN and eQN tert-butyl carbamate congeners indicates no significant level of cooperativity between the calix[4]arene module and the cinchona units in terms of overall chiral recognition, most probably as a consequence of residual conformational flexibility of the calixarene module and the carbamate linkage. Copyright 2003 Wiley-Liss, Inc.

  17. Chromatographic behavior of a new hybrid type RP material containing silica bonded 1,3-alternate 25,27-bis-[cyanopropyloxy]-26,28-bis-[3-propyloxy]-calix[4]arene.

    Science.gov (United States)

    Sliwka-Kaszyńska, Magdalena; Łępicka, Kamila; Slebioda, Marek

    2010-10-01

    A novel 1,3-alternate 25,27-bis-[cyanopropyloxy]-26,28-bis-[3-propyloxy]-calix[4]arene-bonded silica gel stationary phase (CalixPrCN) was prepared and its structure was confirmed by ATR-FTIR spectroscopy and elemental analysis. The CalixPrCN phase was characterized in terms of its surface coverage, hydrophobic selectivity, aromatic selectivity, shape selectivity, hydrogen bonding capacity, residue metal content, and silanol activity based on Tanaka, Lindner, and SMR 870 test protocols. The effect of the acetonitrile content on the retention and selectivity of the selected neutral, basic, and acidic solutes was studied. The neutral and acidic analytes exhibited classical RP behavior, in which retention time decreases with increasing acetonitrile content. In contrast, basic analytes showed an increase in retention at low and high percentages of acetonitrile, forming "U-shaped" retention profiles. The new calixarene phase was compared with previously reported 1,3-alternate 25,27-bis-[propyloxy]-26,28-bis-[3-propyloxy]-calix[4]arene stationary phase and commercial cyanopropyl column. The results indicate that the CalixPrCN stationary phase behaves like RP packing; however, inclusion complex formation, dipole-dipole, and π-π interactions seem to be involved in the separation process. The selectivity of this phase was demonstrated in separation of polynuclear aromatic hydrocarbons, non-steroidal anti-inflammatory drugs, and sulfonamides as analytes.

  18. Calix[4]-bis-crowns and calix[4]-bis-aza-oxa-crowns: from receptors design to molecular machines

    Energy Technology Data Exchange (ETDEWEB)

    Asfari, Z.; Nierlich, M.; Thuery, P.; Lamare, V.; Dozol, J.F.; Leroy, M.; Vicens, J. [CEA, Cadarache, Saint Paul-lez-Durance, (France)

    1996-11-01

    This review article mainly collects our results on the complexation properties of a series of 1,3-calix[4]-bis-crowns in the 1,3-alternate conformation. Due to their high symmetry, these receptors were shown to form mono-and bi-nuclear complexes with alkali metal cations as evidenced by X-ray crystallography and NMR investigations. Among the family those receptors containing 6 oxygen atoms in the poly glycolic chains were proved to be highly selective towards cesium cation. The observed Na+/Cs+ selectivity was exploited in separation process using them as carriers in transport through supported liquid membranes (SLMs). The selectivity was also rationalized through the determination of thermodynamical parameters of the complexation. X-ray structures and molecular modelling showed that the ligands are preorganised to complex cesium cations and were accounted for explaining the high selectivity observed during the transport experiments. ``1 H- and ``133Cs-NMR grave a schematic representation of the formation of binuclear species and of tunneling of the metal through the calixarene unit. Calix[4]-bis-aza-oxa-crowns and related hybrid receptors combining poly oxa aza-and poly oxa crown ether elements which have been synthesized are good candidates for acting as hard-soft receptors. Due to the globular shapes of calix[4]-bis-crowns, molecular world globes as new molecular machines have been prepared. (Author)29 refs.

  19. A novel family of ordered, mesoporous inorganic/organic hybrid polymers containing covalently and multiply bound microporous organic hosts.

    Science.gov (United States)

    Liu, Chunqing; Lambert, Joseph B; Fu, Lei

    2003-05-28

    We have prepared a new family of periodic hybrid polymers containing microporous cavities provided by covalently bound organic hosts. Cyclodextrin (CD) or calixarene (CX) hosts are attached to four or more trialkoxysilyl groups, which are polymerized to form a polysilsesquioxane matrix. Structural integrity is provided by copolymerization with tetraethoxysilane, which produces a polysilicate co-matrix. Periodic order is created by carrying out the polymerization in the presence of a surfactant, cetyltrimethylammonium bromide. The resulting as-synthesized polymers from these three starting materials were characterized by solid-state nuclear magnetic resonance spectroscopy. The (13)C and (29)Si spectra provided evidence for intact polysilsesquioxane, polysilicate, organic host, and surfactant. Removal of the surfactant by washing produced a polymer containing cavities of mesoporous dimensions, in addition to the microporous host cavities. The purpose of introducing mesoporosity is to allow enhanced access of guests to the microporous hosts. Transmission electron microscopy demonstrated that both as-synthesized and solvent-extracted polymers have a periodic structure. All polymers are completely insoluble in water. The as-synthesized CD-containing polymers extracted up to >99% of 4-nitrophenol from aqueous solution, and the solvent-extracted CX-containing polymers extracted up to 67% of Fe(3+) and lesser amounts of other metal cations from aqueous solution, with interesting selectivity patterns. Simple filtration then removes the polymer containing the extracted organic molecule or metal cation. These extraction abilities are superior to previous materials.

  20. Preparation and characterization of a p-tert-butyl-calix[6]-1,4-benzocrown-4-bonded silica gel stationary phase for liquid chromatography.

    Science.gov (United States)

    Li, Lai-Sheng; Da, Shi-Lu; Feng, Yu-Qi; Liu, Min

    2004-06-18

    A p-tert-butyl-calix[6]-1,4-benzocrown-4-bonded silica gel stationary phase (CR6BS) was first prepared via 3-glycidoxypropyltrimethoxysilane as coupling reagent for high performance liquid chromatography. The structure of the new stationary phase was characterized by diffuse reflectance infrared fourier transform spectroscopy (DRIFT), elemental analysis and thermal analysis. The chromatographic performance of the bonded-stationary phase was evaluated by using neutral, acidic and basic solutes as probes. Meanwhile, comparative study of the new stationary phase with a p-tert-butyl-calix[6]arene-bonded silica gel stationary phase (C6BS, the parent) and ODS was done under the same chromatographic conditions. The results show that the new stationary phase has an excellent reversed-phase property, which is similar to C6BS and ODS. However, the selectivities for some aromatic compounds are different from the parent phase (C6BS) and ODS, especially the latter. In one hand, as hybrid of calixarene and crown ether, CR6BS with the oxygen atoms of ether-bridge can provide the complexation sites for the solutes, lacking of C6BS. On the other hand, the rigid conformation of CR6BS may be responsible to the different performance partially. CR6BS exhibits high selectivity in the separation of alkylated aromatics from their parents as compared with C6BS.

  1. Rare earth (Eu 3+ , Tb 3+ ) mesoporous hybrids with calix[4]arene derivative covalently linking MCM-41: Physical characterization and photoluminescence property

    Science.gov (United States)

    Li, Ya-Juan; Yan, Bing; Wang, Li

    2011-09-01

    MCM-41 mesoporous silica has been functionalized with two kinds of macrocylic calixarene derivatives Calix[4] and Calix[4]Br (Calix[4]=P- tert-butylcalix[4]arene, Calix[4]Br=5.11,17.23-tetra- tert-butyl-25.27-bihydroxy-26.28-bibromopropoxycalix[4]arene) through condensation approach of tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as a template. Novel organic-inorganic mesoporous luminescent hybrid containing RE3+ (Eu 3+, Tb 3+) complexes covalently attached to the functionalized ordered mesoporous MCM-41, which are designated as RE-Calix[4]-MCM-41 and RE-Calix[4]Br-MCM-41, respectively, are obtained by sol-gel process. It is found that they all have high surface area, uniform in the mesostructure and good crystallinity. Measurement of the photoluminescence properties show the mesoporous material covalently bonded Tb 3+ complexes (Tb-Calix[4]-MCM-41 and Tb-Calix[4]Br-MCM-41) exhibit the stronger characteristic emission of Tb 3+ and longer lifetime than the corresponding Eu-containing materials Eu-Calix[4]-MCM-41 and Eu-Calix[4]Br-MCM-41 due to the triplet state energy of modified organic ligands Calix[4]-Si and Calix[4]Br-Si match with the emissive energy level of Tb 3+ very well.

  2. "Two-Story" Calix[6]arene-Based Zinc and Copper Complexes: Structure, Properties, and O2 Binding.

    Science.gov (United States)

    De Leener, Gaël; Over, Diana; Smet, Coryse; Cornut, Damien; Porras-Gutierrez, Ana Gabriela; López, Isidoro; Douziech, Bénédicte; Le Poul, Nicolas; Topić, Filip; Rissanen, Kari; Le Mest, Yves; Jabin, Ivan; Reinaud, Olivia

    2017-09-18

    A new "two-story" calix[6]arene-based ligand was synthesized, and its coordination chemistry was explored. It presents a tren cap connected to the calixarene small rim through three amido spacers. X-ray diffraction studies of its metal complexes revealed a six-coordinate ZnII complex with all of the carbonyl groups of the amido arms bound and a five-coordinate CuII complex with only one amido arm bound. These dicationic complexes were poorly responsive toward exogenous neutral donors, but the amido arms were readily displaced by small anions or deprotonated with a base to give the corresponding monocationic complexes. Cyclic voltammetry in various solvents showed a reversible wave for the CuII/CuI couple at very negative potentials, denoting an electron-rich environment. The reversibility of the system was attributed to the amido arms, which can coordinate the metal center in both its +II and +I redox states. The reversibility was lost upon anion binding to Cu. Upon exposure of the CuI complex to O2 at low temperature, a green species was obtained with a UV-vis signature typical of an end-on superoxide CuII complex. Such a species was proposed to be responsible for oxygen insertion reactions onto the ligand according to the unusual and selective four-electron oxidative pathway previously described with a "one-story" calix[6]tren ligand.

  3. Binucleating behaviour of a proximally-diphosphinated calix[4]arene.

    Science.gov (United States)

    Awada, Mouhamad; Jeunesse, Catherine; Matt, Dominique; Toupet, Loic; Welter, Richard

    2011-10-21

    The long diphosphine 5,11-diphenylphosphanyl-25,26-dipropyloxy-27,28-bis(2-propenyloxy) calix[4]arene (cone) (5), in which the two phosphorus atoms are separated by a semi-rigid linking unit, was prepared in four steps starting from calix[4]arene. Reaction of 5 with AuCl(SEt(2)) or [RuCl(2)(p-cymene)](2) led to calixarenes bearing two metallated pendant arms, [5·(AuCl)(2)] and [5·{RuCl(2)(p-cymene)}(2)], respectively. In the presence of AgBF(4) or [Ni(C(5)H(5))(1,5-cyclooctadiene)]BF(4), diphosphine 5 displayed a marked tendency to form oligomeric material, but under high dilution conditions dimeric species were obtained selectively. The inability of 5 to form chelate complexes was further illustrated by its reaction with [PdCl(2)(1,5-cyclooctadiene)(2)], which led quantitatively to a rare complex in which a diphosphine spans across the dinuclear [PdCl(μ-Cl)(2)PdCl] unit. This journal is © The Royal Society of Chemistry 2011

  4. A mixed DFT-MD methodology for the in silico development of drug releasing macrocycles. Calix and thia-calix[N]arenes as carriers for Bosutinib and Sorafenib.

    Science.gov (United States)

    Galindo-Murillo, Rodrigo; Aguilar-Suárez, Luis Enrique; Barroso-Flores, Joaquín

    2016-04-15

    Interaction energies between a family of 36 calix[n]arenes, their corresponding thia- analogues, and two commercially available second generation tyrosine kinase III inhibitors-Bosutinib and Sorafenib-were calculated through DFT methods at the B97D/6-31G(d,p) level of theory, based on Natural Population Analysis, for the in silico development of suitable drug carriers based on the aforementioned macrocycles which can increase their bioavailability and in turn their pharmaceutical efficiency. Molecular Dynamics simulations (production runs: +500 ns) using the General Amber Force Field were also carried out in order to assess the releasing process of these drugs in an explicit aqueous environment. In total, 144 host-guest complexes are examined. According to our results, five-membered -SO3H and i-Pr functionalized-calixarenes are the best candidates for Sorafenib-carriers while six-membered ones -SO3H and C2H4NH2 functionalized- are the lead candidates for Bosutinib-carriers. © 2015 Wiley Periodicals, Inc.

  5. Surface photochemistry: Diffuse reflectance studies of thioketones included into p-tert-butylcalix[6 and 8]arenes

    Science.gov (United States)

    Vieira Ferreira, L. F.; Ferreira Machado, I.; Oliveira, A. S.; Da Silva, J. P.; Krawczyk, A.; Sikorski, M.

    2007-02-01

    This paper presents time resolved laser induced luminescence (LIL) and diffuse reflectance laser flash-photolysis (DRLFP) studies of solid powdered samples of xanthione (XT) and 4H-1-benzopyran-4-thione (BPT). These thioketones form inclusion complexes with p-tert-butylcalix[6]arene (CLX[6]) and p-tert-butylcalix[8]arene (CLX[8]). Room temperature air equilibrated LIL studies for XT/CLX[8] inclusion complex have shown the existence of both fluorescence and delayed fluorescence emission (S 2 → S 0 emissions in the nanosecond and microsecond time ranges, respectively) peaking at ca. 460 nm while phosphorescence peaks at about 670 nm with a half life of about 4 μs. For the BPT/CLX[8] inclusion complex, the emissions now peak at ca. 450 and 630 nm, respectively. When these two thioketones are included into the CLX[6] nanocavities similar luminescence spectra were detected. The phosphorescence spectra in all cases present a clear vibrational structure characteristic of non-polar environments, in accordance with the non-polar character of the calixarene's cavities. Diffuse reflectance transient absorption spectra revealed in all cases the presence of the triplet state of the thioketones and also of longer lived species. The use of chromatographic methods (GC-MS) allowed us to identify the formation of xanthone, chromone and hydroxy-thioketones following laser irradiation at 355 or 337 nm.

  6. Evaluation of Factors Affecting Cesium Extraction Performance by Calix[4]Arene Derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Rumppe, J.L.; Delmau, L.

    2004-01-01

    Novel aza-crown derivatives of dioctyloxy-calix[4]arene crown-6 were examined for their cesium extraction performance at different pH levels. These studies are of interest in addressing high-level waste tank remediation and the removal of 137Cs, a major contributor to heat and radiation generation. Preliminary studies were done to assess the performance of these calixarene compounds under varying conditions. Results showed an increase of cesium extraction with pH as well as expected trends in diluent effects and anion selectivity. Poor extraction performance of some aza-crown derivatives raised questions regarding the possibility of intramolecular hydrogen-bonding. A novel methylated derivative was used to address these questions. Additional experiments were conducted to determine the extraction effect on pH. Results indicate an increase in cesium extraction with pH, as shown in preliminary studies. Mono-aza derivatives were shown to exhibit better cesium extraction performance than their di-aza counterparts. The methylated derivative showed poorer extraction performance than the non-methylated derivative, indicating that completely removing the possibility of intramolecular hydrogen-bonding has negative effects on extraction performance. This suggests that the hydrogen-bonding facilitates anion co-extraction, which would lead to better overall extraction. Mono-aza derivatives were shown to cause unexpected changes in pH. This could possibly be attributed to protonation of the calix crown.

  7. Selective molecular recognition by nanoscale environments in a supported iridium cluster catalyst

    Science.gov (United States)

    Okrut, Alexander; Runnebaum, Ron C.; Ouyang, Xiaoying; Lu, Jing; Aydin, Ceren; Hwang, Son-Jong; Zhang, Shengjie; Olatunji-Ojo, Olayinka A.; Durkin, Kathleen A.; Dixon, David A.; Gates, Bruce C.; Katz, Alexander

    2014-06-01

    The active sites of enzymes are contained within nanoscale environments that exhibit exquisite levels of specificity to particular molecules. The development of such nanoscale environments on synthetic surfaces, which would be capable of discriminating between molecules that would nominally bind in a similar way to the surface, could be of use in nanosensing, selective catalysis and gas separation. However, mimicking such subtle behaviour, even crudely, with a synthetic system remains a significant challenge. Here, we show that the reactive sites on the surface of a tetrairidium cluster can be controlled by using three calixarene-phosphine ligands to create a selective nanoscale environment at the metal surface. Each ligand is 1.4 nm in length and envelopes the cluster core in a manner that discriminates between the reactivities of the basal-plane and apical iridium atoms. CO ligands are initially present on the clusters and can be selectively removed from the basal-plane sites by thermal dissociation and from the apical sites by reactive decarbonylation with the bulky reactant trimethylamine-N-oxide. Both steps lead to the creation of metal sites that can bind CO molecules, but only the reactive decarbonylation step creates vacancies that are also able to bond to ethylene, and catalyse its hydrogenation.

  8. Antibody-free reading of the histone code using a simple chemical sensor array.

    Science.gov (United States)

    Minaker, Samuel A; Daze, Kevin D; Ma, Manuel C F; Hof, Fraser

    2012-07-18

    The histone code refers to the complex network of histone post-translational modifications that control gene expression and are of high interest as drivers of a large number of human diseases. We report here on a mix-and-match toolkit of readily available dyes and calixarene host molecules that can be combined to form dye-displacement sensors that respond to a wide variety of cationic peptides. Using the data from only two or three such simple supramolecular sensors as a chemical sensor array produces fingerprints of data that discriminate robustly among many kinds of histone code elements. "Reads" that are accomplished include the discrimination of unmethylated, mono-, di-, and trimethylated lysines on a single histone tail sequence, identification of different modifications and combinations of modifications on a single histone tail sequence, identification of a single modification type in several different sequence contexts, and identification of isomeric dimethylarginine modifications. Reads that are sometimes troublesome for antibodies are achieved. We also report on the ability of the sensor array to report simultaneously on the concentrations and identities of histone modifications. This sensor array discriminates between post-translationally modified analytes without being limited to partners that contain a single, programmed binding interaction.

  9. DEMONSTRATION OF THE NEXT-GENERATION CAUSTIC-SIDE SOLVENT EXTRACTION SOLVENT WITH 2-CM CENTRIGUGAL CONTRACTORS USING TANK 49H WASTE AND WASTE SIMULANT

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, R.; Peters, T.; Crowder, M.; Pak, D.; Fink, S.; Blessing, R.; Washington, A.; Caldwell, T.

    2011-11-29

    Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet using MaxCalix for the decontamination of high level waste (HLW). The demonstration was completed using a 12-stage, 2-cm centrifugal contactor apparatus at the Savannah River National Laboratory (SRNL). This represents the first CSSX process demonstration of the MaxCalix solvent system with Savannah River Site (SRS) HLW. Two tests lasting 24 and 27 hours processed non-radioactive simulated Tank 49H waste and actual Tank 49H HLW, respectively. A solvent extraction system for removal of cesium from alkaline solutions was developed utilizing a novel solvent invented at the Oak Ridge National Laboratory (ORNL). This solvent consists of a calix[4]arene-crown-6 extractant dissolved in an inert hydrocarbon matrix. A modifier is added to the solvent to enhance the extraction power of the calixarene and to prevent the formation of a third phase. An additional additive is used to improve stripping performance and to mitigate the effects of any surfactants present in the feed stream. The process that deploys this solvent system is known as Caustic Side Solvent Extraction (CSSX). The solvent system has been deployed at the Savannah River Site (SRS) in the Modular CSSX Unit (MCU) since 2008.

  10. Ethylene Control Technologies in Extending Postharvest Shelf Life of Climacteric Fruit.

    Science.gov (United States)

    Zhang, Junhua; Cheng, Dong; Wang, Baobin; Khan, Iqbal; Ni, Yonghao

    2017-08-30

    Fresh fruit is important for a healthy diet. However, because of their seasonal production, regional specific cultivation, and perishable nature, it is essential to develop preservation technologies to extend the postharvest shelf life of fresh fruits. Climacteric fruit adopt spoilage because of ethylene, a key hormone associated with the ripening process. Therefore, controlling ethylene activity by following safe and effective approaches is a key to extend the postharvest shelf life of fruit. In this review, ethylene control technologies will be discussed aiming for the need of developing more innovative and effective approaches. The biosynthesis pathway will be given first. Then, the technologies determining the postharvest shelf life of climacteric fruit will be described with special attention to the latest and significant published works in this field. Special attention is given to 1-methylcyclopropene (1-MCP), which is effective in fruit preservation technologies. Finally, the encapsulation technology to improve the stability of 1-MCP will be proposed, using a potential encapsulation agent of 1-MCP, calixarene.

  11. Comparison of Trimming Techniques for Sub-Lithographic Silicon Structures

    Science.gov (United States)

    Dreeskornfeld, L.; Graham, A. P.; Hartwich, J.; Kretz, J.; Landgraf, E.; Lutz, T.; Rösner, W.; Specht, M.; Risch, L.

    2006-06-01

    The trimming of electron beam features is investigated to explore the limits of this scaling technique for the fabrication of nano-scale devices. The semiconductor industry, in particular, needs features below 50 nm, e.g., for extremely small gates for future technology nodes. In addition, sub-lithographic structures are required for other device concepts, such as the fin-type field effect transistor (FinFET). The trimming of very thin layers of calixarene, an organic resist material, as well as an oxide-like resist (hydrogen-silesquioxane) were investigated and extremely small feature sizes, well below 10 nm, were achieved. Resist structures down to 4 nm in width and silicon features of about 8 nm have been successfully fabricated. Different trimming procedures utilizing plasma resist trimming, etching of Tetraethylorthosilicate (TEOS) hard-masks in hydrofluoric acid (HF) and sacrificial oxidation were compared and, for the first time, a comprehensive study of these techniques applied to sub-10 nm-structuring is presented. In summary, results prove the potential of the trimming procedures investigated here, each of which has specific applications.

  12. Aqua(μ-cone-26,28-dibutoxy-25,27-bis{N-[5-(dimethylaminonaphthalene-1-sulfonyl]carbamoylmethoxy}-5,11,17,23-tetrakis(1,1-dimethylethylcalix[4]arene(2−disodium acetonitrile tetrasolvate

    Directory of Open Access Journals (Sweden)

    Pogisego Dinake

    2012-04-01

    Full Text Available The structure of the title complex, [Na2(C80H98N4O10S2(H2O]·4CH3CN, obtained after crystallization from acetonitrile, contains two formula units in the asymmetric unit (Z′ = 2 and an estimated four molecules of acetonitrile per calixarene moiety. It is unusual for two Na+ ions to occupy the lower rims of the cone calix[4]arene, as in this case, with one Na+ ion forming two O→ Na+ coordinate bonds with the two butoxy groups and four such bonds with the two N-dansyl carboxamide groups, forming six dative bonds between Na+ and O. On the other hand, the other Na+ ion forms only five O→Na+ coordinate bonds on the far end of the calix[4]arene lower rim, bringing the two dansyl groups in close proximity with each other. There also appears to be an O→Na+ coordination coming from a dangling water molecule. The structure contained both resolved and poorly resolved solvent molecules. The latter were treated using the SQUEEZE routine in PLATON [Spek (2009. Acta Cryst. D65, 148–155].

  13. Temperature-regulated guest admission and release in microporous materials

    Science.gov (United States)

    Li, Gang (Kevin); Shang, Jin; Gu, Qinfen; Awati, Rohan V.; Jensen, Nathan; Grant, Andrew; Zhang, Xueying; Sholl, David S.; Liu, Jefferson Z.; Webley, Paul A.; May, Eric F.

    2017-01-01

    While it has long been known that some highly adsorbing microporous materials suddenly become inaccessible to guest molecules below certain temperatures, previous attempts to explain this phenomenon have failed. Here we show that this anomalous sorption behaviour is a temperature-regulated guest admission process, where the pore-keeping group's thermal fluctuations are influenced by interactions with guest molecules. A physical model is presented to explain the atomic-level chemistry and structure of these thermally regulated micropores, which is crucial to systematic engineering of new functional materials such as tunable molecular sieves, gated membranes and controlled-release nanocontainers. The model was validated experimentally with H2, N2, Ar and CH4 on three classes of microporous materials: trapdoor zeolites, supramolecular host calixarenes and metal-organic frameworks. We demonstrate how temperature can be exploited to achieve appreciable hydrogen and methane storage in such materials without sustained pressure. These findings also open new avenues for gas sensing and isotope separation. PMID:28598429

  14. NOVEL FISSION PRODUCT SEPARATION BASED ON ROOM-TEMPERATURE IONIC LIQUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Hussey, Charles L.

    2004-06-01

    The DoE/NE underground storage tanks at Hanford, SRS, and INEEL contain liquid wastes with high concentrations of radioactive species, mainly 137Cs and 90Sr. Because the other components of the liquid waste are mainly sodium nitrate and sodium hydroxide, most of this tank waste can be treated inexpensively as low-level waste if 137Cs and 90Sr can be selectively removed. Many ionophores (crown ether and calixarene compounds) have been synthesized for the purpose of selectively extracting Cs+ and Sr2+ from an aqueous phase into an immiscible organic phase. Recent studies conducted at ORNL1,2 reveal that hydrophobic ionic liquids might be better solvents for extracting metal ions from aqueous solutions with these ionophores than conventional immiscible organic solvents, such as benzene, toluene, and dichloromethane, because both Cs+ and Sr2+ exhibit larger distribution coefficients in the ionic liquids. In addition, the vapor pressures of these ionic liquids are insignificant. Thus, there is little or no vaporization loss of these solvents. Most of the ionic liquids under investigation are relatively nontoxic compared to the hydrocarbon solvents that they replace, classifying them as ''green'' solvents.

  15. Recent Advances in Macrocyclic Fluorescent Probes for Ion Sensing

    Directory of Open Access Journals (Sweden)

    Joseph K.-H. Wong

    2017-01-01

    Full Text Available Small-molecule fluorescent probes play a myriad of important roles in chemical sensing. Many such systems incorporating a receptor component designed to recognise and bind a specific analyte, and a reporter or transducer component which signals the binding event with a change in fluorescence output have been developed. Fluorescent probes use a variety of mechanisms to transmit the binding event to the reporter unit, including photoinduced electron transfer (PET, charge transfer (CT, Förster resonance energy transfer (FRET, excimer formation, and aggregation induced emission (AIE or aggregation caused quenching (ACQ. These systems respond to a wide array of potential analytes including protons, metal cations, anions, carbohydrates, and other biomolecules. This review surveys important new fluorescence-based probes for these and other analytes that have been reported over the past five years, focusing on the most widely exploited macrocyclic recognition components, those based on cyclam, calixarenes, cyclodextrins and crown ethers; other macrocyclic and non-macrocyclic receptors are also discussed.

  16. Supramolecular polymers constructed from macrocycle-based host-guest molecular recognition motifs.

    Science.gov (United States)

    Dong, Shengyi; Zheng, Bo; Wang, Feng; Huang, Feihe

    2014-07-15

    CONSPECTUS: Supramolecular polymers, fabricated via the combination of supramolecular chemistry and polymer science, are polymeric arrays of repeating units held together by reversible, relatively weak noncovalent interactions. The introduction of noncovalent interactions, such as hydrogen bonding, aromatic stacking interactions, metal coordination, and host-guest interactions, endows supramolecular polymers with unique stimuli responsiveness and self-adjusting abilities. As a result, diverse monomer structures have been designed and synthesized to construct various types of supramolecular polymers. By changing the noncovalent interaction types, numbers, or chemical structures of functional groups in these monomers, supramolecular polymeric materials can be prepared with tailored chemical and physical properties. In recent years, the interest in supramolecular polymers has been extended from the preparation of intriguing topological structures to the discoveries of potential applications as functional materials. Compared with traditional polymers, supramolecular polymers show some advantages in the fabrication of reversible or responsive materials. The development of supramolecular polymers also offers a platform to construct complex and sophisticated materials with a bottom-up approach. Macrocylic hosts, including crown ethers, cyclodextrins, calixarenes, cucurbiturils, and pillararenes, are the most commonly used building blocks in the fabrication of host-guest interaction-based supramolecular polymers. With the introduction of complementary guest molecules, macrocylic hosts demonstrate selective and stimuli-responsive host-guest complexation behaviors. By elaborate molecular design, the resultant supramolecular polymers can exhibit diverse structures based on the self-selectivity of host-guest interactions. The introduction of reversible host-guest interactions can further endow these supramolecular polymers with interesting and fascinating chemical

  17. THE ADSORPTION OF Pb(II AND Cr(III BY POLYPROPYLCALIX[4]ARENE POLYMER

    Directory of Open Access Journals (Sweden)

    Suryadi Budi Utomo

    2010-06-01

    Full Text Available A research has been conducted to investigate the adsorption behavior of Pb(II and Cr(III onto polypropylcalix[4]arene polymer. The polypropylcalix[4]arene polymer was synthesized in the presence of H2SO4 catalyst and chloroform under N2 condition for 5 h using 25-allyloxy-26,27,28-trihydroxycalyx[4]arene as the precursor. The Polymer was obtained as yellow crystal with melting point of  288-290 °C and its relative molecular weight was 44.810 g.mol-1. The application of polypropylcalix[4]arene for trapping heavy metal cations and its adsorption model were examined by stirring the suspension of the calixarene in the sample solutions for various pH, time, and concentration of Pb(II and Cr(III solution. Effect of pH on batch experiments for the mentioned ions indicated that the optimum pH for metal binding were 5 for lead(II and chromium(III. The adsorption model of metal ions on polypropylcalix[4]arene followed both the pseudo second order adsorption of Ho's and Langmuir isotherm adsorption kinetics models with rate constant (k were 6.81 x 101 min-1 for Pb(II and 2.64 x 10-2 min-1 for Cr(III. The adsorption equilibrium constant, K, were 5.84 x 105 L.mol-1 for Pb(II and 4.66 x 105 L.mol-1 for Cr(III. The maximum adsorption capacity of polypropylcalix[4]arene to Pb(II and Cr(III were 16.31 and 18.14 mg.g-1 with adsorption energy of 32.90 and 32.34 kJ.mol-1, respectively.   Keywords: polypropylcalix[4]arene, adsorption, Pb(II, and Cr(III

  18. Molecular Dynamics Simulations on the solvation and interfacial behaviour of hydrophobic species. Applications to the TATB hypothesis and to the liquid/liquid extraction of cations to supercritical CO{sub 2}; Simulations par dynamique moleculaire de la solvatation et du comportement interfacial d'especes hydrophobes: application a l'hypothese TATB et a l'extraction liquide/liquide de cations par le CO{sub 2} supercritique

    Energy Technology Data Exchange (ETDEWEB)

    Schurhammer, R

    2001-12-15

    We report molecular dynamics studies on the solvation of charged hydrophobic molecules in pure liquids and at liquid / liquid interfaces. The first part of the thesis deals with the TATB hypothesis according to which the As{phi}{sub 4}{sup +} (TA{sup +}) and B{phi}{sub 4}{sup -} (TB{sup -}) ions have the same free energy of solvation in any solvent. The two ions are found to be solvated differently in pure liquids (water, chloroform, acetonitrile) as at a chloroform / water interface. These results are confirmed by free energy calculations and by simulations on iso-volume spherical S{sup +} and S{sup -} ions, which perfectly meet the TATB criteria. The many methodological tests performed show the importance of (i) the corrected treatment of 'long range interactions' (ii) the precise repartition of atomic charges (iii) the solvent models, especially for water, on the + / - charge discrimination by solvent. In the second part, in relation to the liquid / liquid extraction of cations from water to supercritical CO{sub 2}, we report the behaviour of ions (Cs{sup +}, UO{sub 2}{sup 2+}, Eu{sup 3+}), of un-complexed extractants molecules (tri-n-butylphosphate, calixarene), of their complexes with the cations and nitric acid at a preformed chloroform / water interface and during de-mixing simulations which started from a perfectly mixed CO{sub 2} / water solutions. These studies demonstrate the importance of interfacial phenomena, of simulation conditions and acid and extractant concentrations, in assisted ion extraction to supercritical CO{sub 2}. (author)

  19. Noncovalent endo-binding of fullerenes to diprotonated bisporphyrins.

    Science.gov (United States)

    Jung, Sunghan; van Paauwe, John D; Boyd, Peter D W; Shin, Seung Koo

    2011-12-07

    Noncovalent binding of fullerenes to bisporphyrins was studied in the gas phase by energy-dependent collision-induced dissociation (CID) with Xe under single-collision conditions. The electrospray ionization mass spectra of calix[4]arene-linked bisporphyrins show that bisporphyrins take up to 3-4 protons, depending on the type of meso-substituents. Of the protonated bisporphyrins, the diprotonated species form stable 1:1 complexes with fullerenes (C(60) and C(70)). CID cracking patterns of the diprotonated bisporphyrins indicate that each monomeric porphyrin moiety is singly protonated. CID yield-energy curves obtained from the 1:1 diprotonated bisporphyrin-fullerene complexes suggest that a fullerene occupies the endo-binding site intercalated between the two singly protonated porphyrin moieties. In the cases of 1:2 diprotonated bisporphyrin-fullerene complexes, CID results show that one fullerene binds inside (endo-binding) and the other outside (exo-binding). The exo-binding mode is energetically almost identical to the binding of fullerenes to singly protonated porphyrin monomers. The endo-binding energy is at least twice the exo-binding energy. To gain insights into the binding mode, we optimized structures of diprotonated bisporphyrins and their 1:1 endo-complexes with fullerenes, and calculated the endo-binding energy for C(60), C(70) (end-on), and C(70) (side-on). The endo-binding of fullerenes to diprotonated bisporphyrins nearly doubles the π-π interactions while reducing the electrostatic repulsion between the two singly protonated porphyrin moieties. The side-on binding of C(70) is favored over the end-on binding because the former exerts less steric strain to the lower rim of calixarene.

  20. Theory of circular dichroism of nanomaterials comprising chiral molecules and nanocrystals: plasmon enhancement, dipole interactions, and dielectric effects.

    Science.gov (United States)

    Govorov, Alexander O; Fan, Zhiyuan; Hernandez, Pedro; Slocik, Joseph M; Naik, Rajesh R

    2010-04-14

    Our calculations show that a nonchiral nanocrystal is able to dramatically change the circular dichroism (CD) of a chiral molecule when the nanocrystal and molecule form a complex and couple via dipole and multipole Coulomb interactions. Plasmon resonances of metal nanocrystals in the nanocrystal-molecule complex result in both the resonant enhancement of CD signals of molecules and the appearance of new spectral structures. Two mechanisms, in which a nanocrystal can influence the CD effect, have been identified. The first mechanism is the plasmon-induced change in the electromagnetic field inside the chiral molecule. The second is the optical absorption of the nanocrystal-molecule complex due to the chiral currents inside the metal nanocrystal induced by the dipole of the chiral molecule. The first mechanism creates a change in the angle between the effective electric and magnetic dipoles of the molecule. This mechanism can lead to symmetry breaking and to a plasmon-induced CD signal of the nonchiral molecule. Both mechanisms create interesting Fano-like shapes in the CD spectra. Importantly, the second mechanism gives the main contribution to the CD signal at the plasmon frequency when the absorption band of the chiral molecule is far from the plasmon resonance. This may happen in many cases since many biomolecules are optically active in the UV range, whereas plasmon resonances in commonly used nanometals are found at longer wavelengths. As concrete examples, the paper describes alpha-helix and calixarene ligand molecules coupled with metal nanocrystals. The above results are also applied to complexes incorporating semiconductor nanocrystals. The results obtained here can be used to design a variety of hybrid nanostructures with enhanced and tailored optical chirality in the visible wavelength range.

  1. Fission product solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, B.A.; Bonnesen, P.V.; Sachleben, R.A. [and others

    1998-02-01

    Two main objectives concerning removal of fission products from high-level tank wastes will be accomplished in this project. The first objective entails the development of an acid-side Cs solvent-extraction (SX) process applicable to remediation of the sodium-bearing waste (SBW) and dissolved calcine waste (DCW) at INEEL. The second objective is to develop alkaline-side SX processes for the combined removal of Tc, Cs, and possibly Sr and for individual separation of Tc (alone or together with Sr) and Cs. These alkaline-side processes apply to tank wastes stored at Hanford, Savannah River, and Oak Ridge. This work exploits the useful properties of crown ethers and calixarenes and has shown that such compounds may be economically adapted to practical processing conditions. Potential benefits for both acid- and alkaline-side processing include order-of-magnitude concentration factors, high rejection of bulk sodium and potassium salts, and stripping with dilute (typically 10 mM) nitric acid. These benefits minimize the subsequent burden on the very expensive vitrification and storage of the high-activity waste. In the case of the SRTALK process for Tc extraction as pertechnetate anion from alkaline waste, such benefits have now been proven at the scale of a 12-stage flowsheet tested in 2-cm centrifugal contactors with a Hanford supernatant waste simulant. SRTALK employs a crown ether in a TBP-modified aliphatic kerosene diluent, is economically competitive with other applicable separation processes being considered, and has been successfully tested in batch extraction of actual Hanford double-shell slurry feed (DSSF).

  2. Energy-resolved collision-induced dissociation of non-covalent ions: charge- and guest-dependence of decomplexation reaction efficiencies.

    Science.gov (United States)

    Carroy, Glenn; Lemaur, Vincent; De Winter, Julien; Isaacs, Lyle; De Pauw, Edwin; Cornil, Jérôme; Gerbaux, Pascal

    2016-05-14

    Supramolecular chemistry, and especially host-guest chemistry, has been the subject of great interest in the past few decades leading to the synthesis of host cage molecules such as calixarenes, cyclodextrins and more recently cucurbiturils. Mass spectrometry methods are increasingly used to decipher at the molecular level the non-covalent interactions between the different associated molecules. The present article illustrates that the association between mass spectrometry and computational chemistry techniques proves very complementary to depict the gas-phase dissociation processes of ionic non-covalent complexes when subjected to collisional activation. The selected system associates a nor-seco-cucurbit[10]uril bitopic receptor with different amino compounds (adamantylamine, para-xylylenediamine, and para-phenylenediamine). When subjected to CID experiments, the ternary complexes undergo fragmentation via dissociation of non-covalently bound partners. Interestingly, depending on their charge state, the collisionally excited complexes can selectively expel either a neutral guest molecule or a protonated guest molecule. Moreover, based on energy-resolved CID experiments, it is possible to evaluate the guest molecule dependence on the gas phase dissociation efficiency. We observed that the relative order of gas phase dissociation is charge state dependent, with the adamantylamine-containing complexes being the weakest when triply charged and the strongest when doubly charged. The energetics of the gas-phase dissociation reactions have been estimated by density functional theory (DFT) calculations. We succeeded in theoretically rationalizing the experimental collision-induced dissociation results with a special emphasis on: (i) the charge state of the expelled guest molecule and (ii) the nature of the guest molecule.

  3. Optical and Microcantilever-Based Sensors for Real-Time In Situ Characterization of High-Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Gilbert M.; Bryan, Samuel

    2002-06-01

    Fundamental research is being conducted to develop sensors for strontium that can be used in real-time to characterize high-level waste (HLW) process streams. Two fundamentally different approaches are being pursued, which have in common the dependence on highly selective molecular recognition agents. In one approach, an array of chemically selective sensors with sensitive fluorescent probes to signal the presence of the constituent of interest are coupled to fiber optics for remote analytical applications. The second approach employs sensitive microcantilever sensors that have been demonstrated to have unprecedented sensitivity in solution for Cs+ and CrO4 -. Selectivity in microcantilever-based sensors is achieved by modifying the surface of a gold-coated cantilever with a monolayer coating of an alkanethiol derivative of the molecular recognition agent. The approaches are complementary since fiber optic sensors can be deployed in the highly alkaline environment of HLW, bu t a method of immobilizing a fluorescent molecular recognition agents in a polymer film or bead on the surface of the optical fiber has yet to be demonstrated. The microcantilever-based sensors function by converting molecular complexation into surface stress, and they have been demonstrated to have the requisite sensitivity. However, we will investigate method of protecting Si or SiN microcantilever sensors in the highly alkaline environment of HLW while maintaining high selectivity. One objective of this project is to develop Sr(II) molecular recognition agents with rapidly established equilibria needed for real-time analysis, and initial research will focus on calixarene-crown ethers as a platform. Sensors for alkali metal ions, hydroxide, and temperature will be part of the array of sensor elements that will be demonstrated in this program for both the cantilever and fiber optic sensor approaches.

  4. Optical and Microcantilever-Based Sensors for Real-Time In Situ Characterization of High-Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Gilbert M.; Bryan, Samuel

    2003-06-01

    Fundamental research is being conducted to develop sensors for cesium and strontium that can be used in real-time to characterize high-level waste (HLW) process streams. Two fundamentally different approaches are being pursued, having in common the dependence on highly selective molecular recognition agents. In one approach, an array of chemically selective sensors with sensitive fluorescent probes to signal the presence of the constituent of interest will be coupled to fiber optics for remote analytical applications. The second approach employs sensitive microcantilever sensors that have been demonstrated to have unprecedented sensitivity in solution for Cs+ and CrO4 -. Selectivity in microcantilever-based sensors is achieved by modifying the surface of a gold-coated cantilever with a monolayer coating of an alkanethiol derivative of the molecular recognition agent. The approaches are complementary since fiber optic sensors can be deployed in the highly alkaline environment of HLW, but a method of immobilizing a fluorescent molecular recognition agent in a polymer film or bead on the surface of the optical fiber has yet to be demonstrated. The microcantilever-based sensors function by converting molecular complexation into surface stress, and they have been demonstrated to have the requisite sensitivity. However, a method of protecting Si or SiN microcantilever sensors in the highly alkaline environment of HLW while maintaining high selectivity remains to be demonstrated. The fundamental technology for fiber optic and cantilever sensors has been developed by our collaborators David Walt and Thomas Thundat, respectively, and the goal of this project is to adapt molecular recognition chemistry to the methods already being employed. To develop molecular recognition agents for Cs+ and Sr(II) with rapidly established equilibria needed for real-time analysis, we will focus on calixarene-crown ethers as a platform. Sensors for alkali metal ions, hydroxide, and

  5. Dioxygen activation at a mononuclear Cu(I) center embedded in the calix[6]arene-tren core.

    Science.gov (United States)

    Izzet, Guillaume; Zeitouny, Joceline; Akdas-Killig, Huriye; Frapart, Yves; Ménage, Stéphane; Douziech, Bénédicte; Jabin, Ivan; Le Mest, Yves; Reinaud, Olivia

    2008-07-23

    The reaction of a cuprous center coordinated to a calix[6]arene-based aza-cryptand with dioxygen has been studied. In this system, Cu(I) is bound to a tren unit that caps the calixarene core at the level of the small rim. As a result, although protected from the reaction medium by the macrocycle, the metal center presents a labile site accessible to small guest ligands. Indeed, in the presence of O2, it reacts in a very fast and irreversible redox process, leading, ultimately, to Cu(II) species. In the coordinating solvent MeCN, a one electron exchange occurs, yielding the corresponding [CalixtrenCu-MeCN](2+) complex with concomitant release of superoxide in the reaction medium. In a noncoordinating solvent such as CH2Cl2, the dioxygen reaction leads to oxygen insertions into the ligand itself. Both reactions are proposed to proceed through the formation of a superoxide-Cu(II) intermediate that is unstable in the Calixtren environment due to second sphere effects. The transiently formed superoxide ligand either undergoes fast substitution for a guest ligand (in MeCN) or intramolecular redox evolutions toward oxygenation of Calixtren. Interestingly, the latter process was shown to occur twice on the same ligand, thus demonstrating a possible catalytic activation of O2 at a single cuprous center. Altogether, this study illustrates the oxidizing power of a [CuO2](+) adduct and substantiates a mechanism by which copper mono-oxygenases such as DbetaH and PHM activate O2 at the Cu(M) center to produce such an intermediate capable of C-H breaking before the electron input provided by the noncoupled Cu(H) center.

  6. CMPO-calix[4]arenes with spacer containing intramolecular hydrogen bonding: effect of local rigidification on solvent extraction toward f-block elements.

    Science.gov (United States)

    Chu, Hongzhu; He, Lutao; Jiang, Qian; Fang, Yuyu; Jia, Yiming; Yuan, Xiangyang; Zou, Shuliang; Li, Xianghui; Feng, Wen; Yang, Yuanyou; Liu, Ning; Luo, Shunzhong; Yang, Yanqiu; Yang, Liang; Yuan, Lihua

    2014-01-15

    To understand intramolecular hydrogen bonding in effecting liquid-liquid extraction behavior of CMPO-calixarenes, three CMPO-modified calix[4]arenes (CMPO-CA) 5a-5c with hydrogen-bonded spacer were designed and synthesized. The impact of spacer rotation that is hindered by introduction of intramolecular hydrogen bonding upon extraction of La(3+), Eu(3+), Yb(3+), Th(4+), and UO2(2+) has been examined. The results show that 5b and 5c containing only one hydrogen bond with a less hindered rotation spacer extract La(3+) more efficiently than 5a containing two hydrogen bonds with a more hindered rotation spacer, demonstrating the importance of local rigidification of spacer in the design of extractants in influencing the coordination environment. The large difference in extractability between La(3+) and Yb(3+) (or Eu(3+)) by 5b (or 5c), and the small difference by 5a, suggests intramolecular hydrogen bonding do exert pronounced influence upon selective extraction of light and heavy lanthanides. Log-log plot analysis indicates a 1:1, 2:1 and 1:1 stoichiometry (ligand/metal) for the extracted complex formed between 5b and La(3+), Th(4+), UO2(2+), respectively. Additionally, their corresponding acyclic analogs 7a-7c exhibit negligible extraction toward these metal ions. These results reveal the possibility of selective extraction via tuning local chelating surroundings of CMPO-CA by aid of intramolecular hydrogen bonding. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, L.H.

    2002-10-08

    This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.

  8. A rapid stability indicating LC-method for determination of praziquantel in presence of its pharmacopoeial impurities

    Directory of Open Access Journals (Sweden)

    Hisham Hashem

    2017-02-01

    Full Text Available This study reports for the first time about a stability indicating RP-HPLC method for quantitative determination of Praziquantel (PZQ in bulk powder and dosage form and in presence of its pharmacopoeial impurities. The chromatographic separation was carried out on (Caltrex AI® calixarene column, a relatively new packing material. Chromatography was done using an isocratic binary mobile phase consisting of ACN and 25 mM ammonium acetate (NH4Ac in the ratio of 40:60 at flow rate of 1 mL min−1, 30 °C and 210 nm wavelength for detection. The elution time of PZQ was found to be 6.15 ± 0.03 min. The method was validated for system suitability, linearity, precision, limits of detection and quantitation, specificity, stability and robustness. The robustness study was done for small changes in temperature, flow rate, wavelength of detection and % of ACN in mobile phase. Stability tests were done through exposure of the analyte solution to five different stress conditions: Reflux with 1 N HCl, reflux with 1 N NaOH, reflux with 30% H2O2, thermal degradation of powder and exposure to UV radiation. Limits of detection and quantification were found to be 0.56 and 1.70 μg mL−1, respectively. The recovery value of this method was 100.30% ± 1.10 and the reproducibility was within 1.31.

  9. Expression and purification of native and functional influenza A virus matrix 2 proton selective ion channel.

    Science.gov (United States)

    Desuzinges Mandon, Elodie; Traversier, Aurélien; Champagne, Anne; Benier, Lorraine; Audebert, Stéphane; Balme, Sébastien; Dejean, Emmanuel; Rosa Calatrava, Manuel; Jawhari, Anass

    2017-03-01

    Influenza A virus displays one of the highest infection rates of all human viruses and therefore represents a severe human health threat associated with an important economical challenge. Influenza matrix protein 2 (M2) is a membrane protein of the viral envelope that forms a proton selective ion channel. Here we report the expression and native isolation of full length active M2 without mutations or fusions. The ability of the influenza virus to efficiently infect MDCK cells was used to express native M2 protein. Using a Calixarene detergents/surfactants based approach; we were able to solubilize most of M2 from the plasma membrane and purify it. The tetrameric form of native M2 was maintained during the protein preparation. Mass spectrometry shows that M2 was phosphorylated in its cytoplasmic tail (serine 64) and newly identifies an acetylation of the highly conserved Lysine 60. ELISA shows that solubilized and purified M2 was specifically recognized by M2 antibody MAB65 and was able to displace the antibody from M2 MDCK membranes. Using a bilayer voltage clamp measurement assay, we demonstrate a pH dependent proton selective ion channel activity. The addition of the M2 ion channel blocker amantadine allows a total inhibition of the channel activity, illustrating therefore the specificity of purified M2 activity. Taken together, this work shows the production and isolation of a tetrameric and functional native M2 ion channel that will pave the way to structural and functional characterization of native M2, conformational antibody development, small molecules compounds screening towards vaccine treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Mannosylcalix[n]arenes as multivalent ligands for DC-SIGN.

    Science.gov (United States)

    Morbioli, Ilaria; Porkolab, Vanessa; Magini, Andrea; Casnati, Alessandro; Fieschi, Franck; Sansone, Francesco

    2017-12-01

    DC-SIGN is a receptor protruded from the membrane of immature dendritic cells (DCs) that participates in the activation of the immune response through the recognition of pathogen-associated molecular patterns (PAMPs). On the other hand, HIV exploits the interaction between high-mannose structures of its envelope glycoprotein gp120 and DC-SIGN to be transported towards and infect T-cells. DC-SIGN is involved in the recognition process in the form of a tetramer and the multiple exposition of carbohydrate recognition sites (CRSs) is amplified by the formation on the DCs membrane of patches of tetramers. DC-SIGN is then considered an interesting target to fight the virus and multivalent systems exposing multiple copies of ligating units for its CRSs are becoming valuable tools to reach this goal. We herein prepared four mannosylated calix[n]arenes (1a-d) and tested them by Surface Plasmon Resonance (SPR) competition assays as inhibitors of the binding between DC-SIGN and a mannosylated BSA used as model of HIV gp120. IC50s in the μM range were found evidencing in particular for compound 1a that, although rather moderate, a multivalent effect is taking place in the inhibition activity of this cluster. A relative potency (rp/n) around 4, respect to the monovalent methyl α-mannoside and normalized for the number of monosaccharide on the scaffold, was observed. This result, compared with previously reported data relative to dendrimers with the same valency, indicates the calixarene as a promising scaffold to build efficient inhibitors for DC-SIGN and, in perspective, for HIV. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Resist requirements and limitations for nanoscale electron-beam patterning.

    Energy Technology Data Exchange (ETDEWEB)

    Liddle, J. A.; Gallatin, G. M.; Ocola, L. E.; Experimental Facilities Division (APS); LBNL; IBM T.J. Watson Research Center

    2003-01-01

    Electron beam lithography still represents the most effective way to pattern materials at the nanoscale, especially in the case of structures, which are not indefinitely repeating a simple motif. The success of e-beam lithography depends on the availability of suitable resists. There is a substantial variety of resist materials, from PMMA to calixarenes, to choose from to achieve high resolution in electron-beam lithography. However, these materials suffer from the limitation of poor sensitivity and poor contrast. In both direct-write and projection e-beam systems the maximum beam current for a given resolution is limited by space-charge effects. In order to make the most efficient use of the available current, the resist must be as sensitive as possible. This leads, naturally, to the use of chemically amplified (CA) systems. Unfortunately, in the quest for ever smaller feature sizes and higher throughputs, even chemically amplified materials are limited: ultimately, sensitivity and resolution are not independent. Current resists already operate in the regime of < 1 electron/nm2. In this situation detailed models are the only way to understand material performance and limits. Resist requirements, including sensitivity, etch selectivity, environmental stability, outgassing, and line-edge roughness as they pertain to, high-voltage (100 kV) direct write and projection electron-beam exposure systems are described. Experimental results obtained on CA resists in the SCALPEL exposure system are presented and the fundamental sensitivity limits of CA and conventional materials in terms of shot-noise and resolution limits in terms of electron-beam solid interactions are discussed.

  12. Pillararenes, a new class of macrocycles for supramolecular chemistry.

    Science.gov (United States)

    Xue, Min; Yang, Yong; Chi, Xiaodong; Zhang, Zibin; Huang, Feihe

    2012-08-21

    Because of the importance of novel macrocycles in supramolecular science, interest in the preparation of these substances has grown considerably. However, the discovery of a new class of macrocycles presents challenges because of the need for routes to further functionalization of these molecules and good host-guest complexation. Furthermore, useful macrocylic hosts must be easily synthesized in large quantities. With these issues in mind, the recently discovered pillararenes attracted our attention. These macrocycles contain hydroquinone units linked by methylene bridges at para positions. Although the composition of pillararenes is similar to that of calixarenes, they have different structural characteristics. One conformationally stable member of this family is pillar[5]arene, which consists of five hydroquinone units. The symmetrical pillar architecture and electron-donating cavities of these macrocycles are particularly intriguing and afford them with some special and interesting physical, chemical, and host-guest properties. Due to these features and their easy accessibility, pillararenes, especially pillar[5]arenes, have been actively studied and rapidly developed within the last 4 years. In this Account, we provide a comprehensive overview of pillararene chemistry, summarizing our results along with related studies from other researchers. We describe strategies for the synthesis, isomerization, and functionalization of pillararenes. We also discuss their macrocyclic cavity sizes, their host-guest properties, and their self-assembly into supramolecular polymers. The hydroxyl groups of the pillararenes can be modified at all positions or selectively on one or two positions. Through a variety of functionalizations, researchers have developed many pillararene derivatives that exhibit very interesting host-guest properties both in organic solvents and in aqueous media. Guest molecules include electron acceptors such as viologen derivatives and (bis

  13. Dispersed metal cluster catalysts by design. Synthesis, characterization, structure, and performance

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Ilke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dixon, David A. [Univ. of Alabama, Tuscaloosa, AL (United States); Gates, Bruce C. [Univ. of California, Davis, CA (United States); Katz, Alexander [Univ. of California, Berkeley, CA (United States)

    2015-09-30

    To understand the class of metal cluster catalysts better and to lay a foundation for the prediction of properties leading to improved catalysts, we have synthesized metal catalysts with well-defined structures and varied the cluster structures and compositions systematically—including the ligands bonded to the metals. These ligands include supports and bulky organics that are being tuned to control both the electron transfer to or from the metal and the accessibility of reactants to influence catalytic properties. We have developed novel syntheses to prepare these well-defined catalysts with atomic-scale control the environment by choice and placement of ligands and applied state-of-the art spectroscopic, microscopic, and computational methods to determine their structures, reactivities, and catalytic properties. The ligands range from nearly flat MgO surfaces to enveloping zeolites to bulky calixarenes to provide controlled coverages of the metal clusters, while also enforcing unprecedented degrees of coordinative unsaturation at the metal site—thereby facilitating bonding and catalysis events at exposed metal atoms. With this wide range of ligand properties and our arsenal of characterization tools, we worked to achieve a deep, fundamental understanding of how to synthesize robust supported and ligand-modified metal clusters with controlled catalytic properties, thereby bridging the gap between active site structure and function in unsupported and supported metal catalysts. We used methods of organometallic and inorganic chemistry combined with surface chemistry for the precise synthesis of metal clusters and nanoparticles, characterizing them at various stages of preparation and under various conditions (including catalytic reaction conditions) and determining their structures and reactivities and how their catalytic properties depend on their compositions and structures. Key characterization methods included IR, NMR, and EXAFS spectroscopies to identify

  14. Supported Intrinsically Porous Oligomers as Hybrid Materials for Separations, Storage, and Sensing

    Science.gov (United States)

    Thompson, Anthony Boone

    be promising for hydrogen storage via spillover. Finally, to demonstrate other potential uses of supported intrinsically porous oligomers, a TiO2-supported calixarene material was synthesized and used as a simple molecular sensor, opening up the possibility of using these materials for sensing. Overall, the methods used here result in robust hybrid materials with narrow adsorption site distributions and therefore are of potential use in many future applications.

  15. V5 AND V10 CONTACTOR TESTING WITH THE NEXT GENERATION (CSSX) SOLVENT FOR THE SAVANNAH RIVER SITE INTEGRATED SALT DISPOSITION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Restivo, M.; Peters, T.; Pierce, R.; Fondeur, F.; Steeper, T.; Williams, M.; Giddings, B.; Hickman, B.; Fink, S.

    2012-01-17

    A solvent extraction system for removal of cesium (Cs) from alkaline solutions was developed utilizing a novel solvent invented at the Oak Ridge National Laboratory (ORNL). This solvent consists of a calix[4]arene-crown-6 extractant dissolved in an inert hydrocarbon matrix. A Modifier is added to the solvent to enhance the extraction power of the calixarene and to prevent the formation of a third phase. An additional additive, called a suppressor, is used to improve stripping performance. The process that deploys this solvent system is known as Caustic Side Solvent Extraction (CSSX). The solvent system has been deployed at the Savannah River Site (SRS) in the Modular CSSX Unit (MCU) since 2008. Subsequent development efforts by ORNL identified an improved solvent system that can raise the expected decontamination factor (DF) in MCU from {approx}200 to more than 40,000. The improved DF is attributed to an improved distribution ratio for cesium [D(Cs)] in extraction from {approx}15 to {approx}60, an increased solubility of the calixarene in the solvent from 0.007 M to >0.050 M, and use of boric acid (H{sub 3}BO{sub 3}) stripping that also yields improved D(Cs) values. Additionally, the changes incorporated into the Next Generation CSSX Solvent (NGS) are intended to reduce solvent entrainment by virtue of more favorable physical properties. The MCU and Salt Waste Processing Facility (SWPF) facilities are actively pursuing the changeover from the current CSSX solvent to the NGS solvent. To support this integration of the NGS into the MCU and SWPF facilities, the Savannah River Remediation (SRR)/ARP/MCU Life Extension Project requested that the Savannah River National Laboratory (SRNL) perform testing of the new solvent for the removal of Cs from the liquid salt waste stream. Additionally, SRNL was tasked with characterizing both strip (20-in long, 10 micron pore size) and extraction (40-in long, 20 micron pore size) coalescers. SRNL designed a pilot-scale experimental

  16. Next Generation Extractants for Cesium Separation from High-Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A [ORNL; Bazelaire, Eve [ORNL; Bonnesen, Peter V [ORNL; Custelcean, Radu [ORNL; Delmau, Laetitia Helene [ORNL; Ditto, Mary E [ORNL; Engle, Nancy L [ORNL; Gorbunova, Maryna [ORNL; Haverlock, Tamara [ORNL; Levitskaia, Tatiana G. [Pacific Northwest National Laboratory (PNNL); Bartsch, Richard A. [Texas Tech University, Lubbock; Surowiec, Malgorzata A. [Texas Tech University, Lubbock; Marquez, Manuel [University of Texas; Zhou, Hui [Texas Tech University, Lubbock

    2006-01-01

    This project seeks a fundamental understanding and major improvement in cesium separation from high-level waste by cesium-selective calixcrown extractants. Systems of particular interest involve novel solvent-extraction systems containing specific members of the calix[4]arene-crown-6 family, alcohol solvating agents, and alkylamines. Questions being addressed bear upon cesium binding strength, extraction selectivity, cesium stripping, and extractant solubility. Enhanced properties in this regard will specifically benefit applied projects funded by the USDOE Office of Environmental Management to clean up sites such as the Savannah River Site (SRS), Hanford, and the Idaho National Environmental and Engineering Laboratory. The most direct beneficiary will be the SRS Salt Processing Project, which has recently identified the Caustic-Side Solvent Extraction (CSSX) process employing a calixcrown as its preferred technology for cesium removal from SRS high-level tank waste. Disposal of high-level waste is horrendously expensive, in large part because the actual radioactive matter in underground waste tanks at various USDOE sites has been diluted over 1000-fold by ordinary inorganic chemicals. To vitrify the entire mass of the high-level waste would be prohibitively expensive. Accordingly, an urgent need has arisen for technologies to remove radionuclides such as {sup 137}Cs from the high-level waste so that the bulk of it may be diverted to cheaper low-level waste forms and cheaper storage. To address this need in part, chemical research at Oak Ridge National Laboratory (ORNL) has focused on calixcrown extractants, molecules that combine a crown ether with a calixarene. This hybrid possesses a cavity that is highly complementary for the Cs{sup +} ion vs. the Na+ ion, making it possible to cleanly separate cesium from wastes that contain 10,000- to 1,000,000-fold higher concentrations of sodium. Previous EMSP results in Project 55087 elucidated the underlying extraction

  17. One-step orthogonal-bonding approach to the self-assembly of neutral rhenium-based metallacycles: synthesis, structures, photophysics, and sensing applications.

    Science.gov (United States)

    Thanasekaran, Pounraj; Lee, Chung-Chou; Lu, Kuang-Lieh

    2012-09-18

    Self-assembled metallacycles offer structural diversity and interesting properties based on their unique frameworks and host-guest chemistry. As a result, the design and synthesis of these materials has attracted significant research interest. This Account describes our comprehensive investigations of an effective orthogonal-bonding approach for the self-assembly of neutral Re-based metallacycles. We discuss the various types of assemblies that can be created based on the nuclearity of the luminophore, including bimetallic materials, rectangles, cages, and calixarenes. This approach permits the preparation of a rectangular molecule, rather than two molecular squares, in excellent yields. We extended this strategy to the high yield synthesis of a series of Re-based metallacycles with different shapes. With the rich spectroscopic and luminescence properties, Re(I) metallacycles provide an excellent platform for studies of host-guest interactions. When possible, we also present potential applications of the luminescent Re-based metallosupramolecular assemblies. The orthogonal-bonding approach involves the simultaneous introduction of two ligands: a bis-chelating ligand to coordinate to two equatorial sites of two fac-(CO)(3)Re cores and a monotopic or ditopic nitrogen-donor ligand to the remaining orthogonal axial site. Furthermore, by the appropriate choice of the predesigned organic ligands with various backbones and connectivity information and fac-Re(CO)(3) metal centers, we could also design other novel functional metallacycles including rotors, gondolas, cages, triangles, and metallacalixarenes in high yields. The incorporation of flexible ligands into the Re(I) metallacycles allows us to introduce various conformation states and novel structures. As a result, these structures acquire new functions, such as adaptive recognition properties. For example, we assembled Re(I)-based metallacyclic rotors via a one-step process. These rotors, which contain a para

  18. Synthetic ion transporters that work with anion-π interactions, halogen bonds, and anion-macrodipole interactions.

    Science.gov (United States)

    Vargas Jentzsch, Andreas; Hennig, Andreas; Mareda, Jiri; Matile, Stefan

    2013-12-17

    these elusive interactions in action, we synthesized naphthalenediimide transporters of increasing π-acidity up to an unprecedented quadrupole moment of +39 Buckinghams and characterized these systems in comparison with tandem mass spectrometry and computational simulations. With π-acidic calixarenes and calixpyrroles, we have validated our results on anion-π interactions and initiated our studies of halogen bonds. Halogen bonds originate from the σ-hole that appears on top of electron-deficient iodines, bromines, and chlorines. Halogen-bond donors are ideal for anion transport because they are as strong and at least as directional as hydrogen-bond donors, but also hydrophobic. The discovery of the smallest possible organic anion transporter, trifluoroiodomethane, illustrates the power of halogen-bond donors. This molecule contains a single carbon atom and is a gas with a boiling point of -22 °C. Anion-macrodipole interactions, finally, differ significantly from anion-π interactions and halogen bonds because they are important in nature and cannot be studied with small molecules. We have used anion-transporting peptide/urea nanotubes to examine these interactions in synthetic transport systems. To facilitate the understanding of the described results, we also include an in-depth discussion of the meaning of Hill coefficients. The use of synthetic transport systems to catch less common noncovalent interactions at work is important because it helps to expand the collection of interactions available to create functional systems. Progress in this direction furthers fundamental knowledge and invites many different applications. For illustration, we briefly discuss how this knowledge could apply to the development of new catalysts.