To see the other types of publications on this topic, follow the link: Calixareni.
Dissertations / Theses on the topic 'Calixareni'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Calixareni.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Talotta, Carmen. "Congegni Supramolecolari basati sul Threading di Calixareni." Doctoral thesis, Universita degli studi di Salerno, 2013. http://hdl.handle.net/10556/1475.
Full textAbstract:
2011 - 2012Recently, Neri et al have introduced an efficient method to obtain endo-cavity complexation and through-the-annulus threading of large calixarenes exploiting the inducing effect of a weakly coordinating anion, tetrakis [3,5-bis (trifluoromethyl) phenyl]borate (TFPB-). In this PhD thesis this approach has been used for the synthesis of [2]rotaxanes, which showed an unprecedented inversion of the wheel orientation. Subsequently, it was extended to the synthesis of pseudo[3]rotaxane systems in which two calix[6]arene macrocycles are threaded by a bis(benzylalkylammonium) axle. Because of the three-dimensional nonsymmetrical nature of the calix[6]arene wheels, in these instances three sequence stereoisomers could be obtained, which were termed as headto- head (H,H), head-to-tail (H,T) and tail-to-tail (T,T). Taking advantage of these systems, it was possible to obtain the stereoprogrammed synthesis of the first examples of calixarene-based [3]rotaxane architectures. The base/acid treatment demonstrated that these systems act as molecular shuttles, which move on a nanometer scale level. The directionality of the threading and the observed high stereoselection have enabled the synthesis of directional calix[6]arene-based catenane. All these aspects represent interesting peculiar features of calixarene threading, which could be exploited for designing molecular machines with new properties or functions
XI n.s.
2
Ciao, Roberta. "New chemical topologies based on calixarene threading." Doctoral thesis, Universita degli studi di Salerno, 2014. http://hdl.handle.net/10556/1428.
Full textAbstract:
2012 - 2013Recently, Neri et al. have introduced an efficient method to obtain endo-cavity complexation and through-the-annulus threading of large calixarenes by exploiting the inducing effect of the weakly coordinating tetrakis[3,5-bis-trifluoromethyl)phenyl]borate (TFPB-) anion. The corresponding calix[6]-arene/dialkylammonium pair can be considered a versatile recognition motif, which can be used for the construction of a large variety of calixarene-threaded architectures. This Ph. D. thesis deals with the exploration of the stereochemical features of the threading of hosts containing multiple cavities. Therefore, the synthesis of double- and triple-calixarenes is reported, which is followed by the subsequent study of their threading abilities with dialkylammonium axles.The results confirmed the now well-known endo-alkyl rule of calix[6]arenes that give the inclusion of alkyl chains inside the calix-cavity. On this basis, we were then able to build new attractive chemical topologies. In particular, doubly-threaded pseudo[3]rotaxane structures have been obtained by the threading of double-calixarene hosts with mono-ammonium axles. The subsequent extention to triple-calixarene hosts, in which three macrocycles are covalently linked to one another by means of an appropriate spacer, gave triply-threaded pseudo[4]rotaxane structures. Because of the three-dimensional nonsymmetrical nature of the calix[6]arene wheels, by threading double-calixarene hosts with bis-ammonium axles three examples of beautiful stereoisomeric calixarene-based handcuff rotaxanes were obtained, which could be termed as head-to-head (H,H), head-to-tail (H,T), and tail-to-tail (T,T). On the basis of these results, it is conceivable that the extension of this approach could lead to novel mechanically interlocked architectures with high-order topologies. [edited by author]
XII n.s.
3
Tommasone, Stefano. "Synthesis of calixarene derivatives active towards proteic targets involved in tumor pathologies." Doctoral thesis, Universita degli studi di Salerno, 2016. http://hdl.handle.net/10556/2213.
Full textAbstract:
2014 - 2015Over the last 30 years a growing interest has been direct toward the biomolecular recognition of calixarene derivatives and more in particular to the interaction with druggable target(s).1,2 The aim of this PhD thesis was the synthesis and the study of calixarenes that were able to interact with biomolecules involved in tumor pathologies. One of the main topic of this work was the synthesis of calix[4]arene conjugates bearing pyrenylisoxazolidine moieties at the exo rim which could act as potential DNA intercalators. The in vitro cytotoxic activity against different human tumor cell lines was also tested. Moreover, the biomolecular recognition abilities of designed calixarenes was studied through a chemical proteomics approach. As calix[n]arene scaffolds are particularly suitable for the synthesis of multivalent ligands,3 the attention was also focused on the synthesis of multivalent iminosugar-calix[8]arene conjugates for the inhibition of glycosidases. The synthesis, characterization and all the biomolecular recognition studies were herein described. [edited by author]
XIV n.s.
4
Ferreira, Paula Anastácia. "Modulação de vias de sinalização para indução de morte de células leucêmicas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314038.
Full textAbstract:
Orientador: Carmen Veríssima FerreiraTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-16T13:47:52Z (GMT). No. of bitstreams: 1 Ferreira_PaulaAnastacia_D.pdf: 2451128 bytes, checksum: a13caa2510a3ac1dca624878d50fafab (MD5) Previous issue date: 2010
Resumo: A eficiência do tratamento da leucemia sob vários aspectos, mesmo com os avanços farmacotecnológicos, ainda permanece como desafio para a medicina. Diante desse fator, maiores informações sobre a base molecular da leucemia e o desenvolvimento de agentes que atuem de forma alvo-específico, apresentem poucos efeitos colaterais e possam impedir o escape das células tumorais à indução de morte são extremamente desejáveis. No presente trabalho, foram abordados 2 aspectos: indução de morte das células leucêmicas por calix[6]areno, flavonóides e diterpeno lactona e contribuição da proteína tirosina fosfatase de baixo massa molecular (LMWPTP) para a resistência de células leucêmicas. As linhagens K562, Lucena-1 (resistente) e HL60 foram utilizadas como modelos no estudo. Calix[6]areno apresentou o mesmo nível de toxicidade para as duas linhagens celulares, mostrando valores de IC50 na faixa de 1-5 µM para K562 e 5-10 µM para Lucena-1. Calix[6]areno induziu vias apoptóticas como demonstrado pelo aumento da razão Bax/Bcl-2 e clivagem de PARP. A proteína tirosina fosfatase PTEN foi ativada pelo Calix[6]areno, fato relacionado com a diminuição da sobrevivência e proliferação. O Calix[6]areno aumentou a expressão de algumas enzimas antioxidantes e não afetou a atividade da proteína associada com o fenótipo de resistência, P-Glicoproteína. As células Lucena-1, que apresentam alta expressão da P-Glicoproteína, também apresentam altos níveis da LMWPTP. Observamos que quando esta enzima foi silenciada, a resposta frente a quimioterápicos das células leucêmicas se tornou mais eficiente. Por outro lado, o aumento da expressão da LMWPTP em células não resistentes provocou insensibilidade das mesmas à vincristina. Nossos dados sugerem que a LMWPTP contribui com o fenótipo resistente através da ativação das quinases Src e BCR-ABL. Outro aspecto investigado neste trabalho foi a indução da diferenciação e apoptose por compostos naturais. Quercetina e a apigenina apresentaram os dois efeitos desejados a um agente quimioterápico, ou seja, expressiva indução da diferenciação das células e também apoptose. Estes efeitos foram dependentes do tempo e modulação do estado redox celular.
Abstract: Leukemia therapy efficiency, under several aspects, even with the progress of pharmacotechnology, remains as a challenge in medicine. According to this, new information about the molecular basis of leukemia and development of agents that act on specific target, present low side-effects and prevent cancer cells escaping from death induction, are extremely desirable. In this work 2 aspects were evaluated: death induction of leukemia cells by calix[6]arene, flavonoids and diterpene lactone and the contribution of the low molecular weight protein tyrosine phosphatase (LMWPTP) for leukemia cells resistance. K562, Lucena-1 and HL60 cells were used as models in this study. Calix[6]arene presented the same level of toxicity on K562 and Lucena-1 cells, displaying an IC50 value ranging 1-5 µM to K562 cells and 5-10 µM to Lucena-1 cells. Calix[6]arene induce apoptosis signaling on both K562 and Lucena cells as molecularly demonstrated by the increased Bax/Bcl-2 ratio and PARP cleavage. Protein tyrosine phosphatase PTEN from leukemia cells became more active in the presence of calix[6]arene, which is related to a decrease of survival and proliferation. Calix[6]arene enhanced the expression of antioxidant enzymes and did not affect P-Glycoprotein activity. Lucena cells, which present high expression of P-Glycoprotein also contain high level of LMWPTP. Interestingly, when this phosphatase was silenced the leukemia cells response appeared to be more efficient towards chemotherapics. On the other hand, overexpression of this enzyme in K562 (non resistant cells) provoked insensitivity to vincristine. Our findings suggest that LMWPTP contributes with the resistance phenotype by supporting the activation status of Src and BCR-ABL kinases. Another aspect examined in this study was the induction of differentiation and apoptosis by natural compounds. Quercetin and apigenin displayed both desired effects of chemotherapics: induction of differentiation and apoptosis. These effects were time- and cellular redox status dependent.
Doutorado
Bioquimica
Doutor em Biologia Funcional e Molecular
5
Lavendomme, Roy. "Development of strategies for the highly selective functionalization of calixarenes and study of host–guest properties of calixarene-based molecular boxes." Doctoral thesis, Universite Libre de Bruxelles, 2016. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/241320.
Full textAbstract:
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 leur conférer des propriétés utiles aux applications visées (e.g. affinité envers certaines espèces chimiques, hydrosolubilité, activité photoluminescente). La modification sélective de tels macrocycles oligomériques est cependant loin d’être triviale car, en plus de requérir un contrôle des chimio- régio- et stéréosélectivités classiques, la réaction d’un nombre défini de fonctions identiques est une problématique clé qui doit être résolue. En effet, la fonctionnalisation des oligomères cycliques tels que les calixarènes passe par la formation de produits mono-, di-, tri-fonctionnalisés, et ainsi de suite de manière itérative. Par analogie avec des processus itératifs, nous avons proposé le terme « itérosélectivité » pour décrire la sélectivité qui gouverne le nombre de transformations chimiques répétées. Dans ce contexte, nous avons proposé des stratégies rationnelles et hautement sélectives pour la fonctionnalisation de calixarènes. Ces stratégies exploitent principalement des réactions de carbamatation pour introduire sélectivement des groupements tert-butylaminocarbonyle (Bac) sur les positions phénoliques des calixarènes. Citons notamment la carbamatation « all-but-one » qui permet d’introduire itérosélectivement des groupements Bac sur tous les phénols sauf un pour une grande variété de calixarènes. De plus, l’utilisation de ces groupements Bac comme groupe protecteur nous a permis de synthétiser de nombreux dérivés calixaréniques jusqu’alors inaccessibles suivant les voies de fonctionnalisation connues. Certains de ces composés présentent notamment une chiralité inhérente. En dehors de nos travaux, aucune voie de fonctionnalisation sélective de calixarènes décrite à ce jour n’est aussi générale et efficace. Nous avons également présenté une nouvelle voie d’oxydation de calixarènes en calixquinones. Cette voie présente moins de risques pour la santé et l’environnement que la méthode la plus couramment utilisée à ce jour employant un sel de thallium, métal extrêmement toxique. Les différents aspects synthétiques développés ont permis de synthétiser des boites moléculaires originales dérivées de calixarènes qui ont été étudiées pour leurs propriétés intéressantes dans le cadre de la reconnaissance sélective de petites molécules dont l’eau et le DMSO, ainsi que le piégeage de gaz à l’état solide dont l’hexafluorure de soufre qui est le gaz à effet de serre le plus puissant répertorié à ce jour. Pour finir, la caractérisation poussée d’une bibliothèque de dérivés calixaréniques par spectroscopie de résonance magnétique nucléaire a permis de décrire une méthode générale pour la caractérisation structurale et conformationnelle des calixarènes.This work concerns the study of polyphenolic platforms, and more particularly, of calixarenes. Oligomeric macrocycles such as calixarenes, cyclodextrins, cyclotriveratrylenes, pillararenes, etc. are widely used as molecular platforms in supramolecular chemistry and in particular for the design of sensors, catalysts, multivalent systems, biomimetic receptors, etc. In general, the synthesis of such supramolecular systems requires the controlled introduction of functional groups on the precursor platform. However, the development of efficient methods for selective modification of macrocyclic oligomers remains extremely challenging. Indeed, in addition to the control of the classical chemo-, regio-, and stereoselectivities, the reaction of a defined number of identical functional groups is a key issue that must be solved. Indeed, the functionalization of oligomeric macrocycles such as calixarenes goes through the formation of mono-, di, tri-functionalized products and so on, iteratively. By analogy with iterative processes, we proposed to name “iteroselectivity” the kind of selectivity that governs the number of repeating chemical transformations. In this context, we proposed rational and highly selective strategies for the functionalization of calixarenes. These strategies are mainly based on the carbamatation of calixarene phenolic functions to introduce tert-butylaminocarbonyl groups (i.e. Bac groups). Our leading example is the “all-but-one” carbamatation which can be used to introduce Bac groups on all but one phenol of a large variety of calixarenes. Moreover, using Bac groups as protecting groups led to the synthesis of numerous calixarene derivatives which were, until now, not accessible through conventional means. It is noteworthy that some of these compounds are inherently chiral. No other selective functionalization method described for calixarenes is as general and efficient than this “all-but-one” carbamatation. Besides, we also described a new oxidation method to synthesize calixquinone starting from calixarenes. This method is less risky and more environment-friendly than the most commonly used method which rely on thallium salts, an extremely toxic metal. Through the various synthetic methods developed herein, we also developed calixarene-based molecular boxes. The host–guest properties of these molecular boxes were studied revealing their ability to include small molecules such as water or DMSO. We also developed a method to sequester gases in the solid state relying on an original concept involving calix[6]arene-based molecular boxes. This was exemplified with the sequestration of SF6, known as the most potent greenhouse gas. At last, the extensive characterization of a library of calixarene derivatives by nuclear magnetic resonance spectroscopy led to the development of a general method for the structural and conformational characterization of calixarenes.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
6
Dougherty, Gary. "Electrochemically switchable calixarene ionophores." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240418.
Full textAbstract:
The synthesis of a series of p-tert-butylcalixI4Iarcne based, electrochemically switchable, ionophores (1), (2), (3), (4) and (5) is described. Their electrochemical properties were investigated in the presence of added Croup I metal perchloratcs. Both compounds (1) and (2) displayed no enhancement of binding for metal ions, due to electrostatic interactions, upon electrochemical reduction. This behaviour is explained on steric grounds, as deduced by molecular modelling. Compounds (3), (4) and (5) all display significant enhancements of metal ion binding upon electrochemical reduction. Compounds (4) and (5) appear to display a high selectivity for sodium ions over other Croup I metal ions. Compound (3) displayed the highest binding enhancements yet recorded for both sodium (3.138 x loS) and potassium (1.398 x 103) ions. Compound (6) (from which (3), (4) and (5) were malic) could be converted to m,my other compounds in which the side arms bear difierent functional groups in an eiiort to control selectivity. For example thio esters or thin arnides for silver, ethyl groups tor potassium.
7
De, Simone Nicola Alessandro. "Calixarene based catalytic systems." Doctoral thesis, Universita degli studi di Salerno, 2018. http://hdl.handle.net/10556/3187.
Full textAbstract:
2016 - 2017Catalysis is the essence of chemistry as it provides useful tools to make and brake chemical bonds. As nature has been a guide to many scientists, it’s no surprise that in the field of catalysis enzymes were a source of inspiration. Harnessing non covalent interactions, as enzymes do, is a fascinating perspective, and, since supramolecular chemistry became more and more involved in catalysis, a new discipline was born, named supramolecular catalysis. Since supramolecular hosts such as calix[n]arenes have been fruitfully employed in the synthesis of catalysts, in these work we report the design, characterization and applications of new calixarene based catalytic systems. In details chiral calix[4]arene amides 1-7 were employed as phase-transfer catalysts thanks to their cation complexing properties, while the calix[4]arene functionalized with a chiral primary amine-thiourea moiety 8 acted as bifunctional catalyst in several asymmetric conjugate addiction reactions. Finally dinuclear Zirconium-calix[8]arene complex 9 proved to be active in the ring opening polymerization of cyclic esters... [edited by author]
XVI n.s.
8
Taylor, Stephanie Merac. "Calixarene supported transition metal clusters." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7770.
Full textAbstract:
This thesis describes a series of calix[n]arene polynuclear transition metal and lanthanide complexes. Calix[4]arenes possess lower-rim polyphenolic pockets that are ideal for the complexation of various transition metal and lanthanide centres. Surprisingly however, with only a few exceptions, the coordination chemistry of p-tBucalix[ 4]arene (TBC[4]), p-tBu-calix[8]arene (TBC[8]) and p-tBuhomotrioxacalix[ 3]arene (TBOC[3]) with paramagnetic transition metal ions for the purpose of making and studying magnetically interesting molecules is unknown. Chapter two describes the reaction of TBC[4] with manganese salts in the presence of an appropriate base (and in some cases co-ligand) resulting in the formation of a family of calixarene-supported [MnIII 2MnII 2] clusters (1-7) that behave as Single-Molecule Magnets (SMMs). These are: [MnIII 2MnII 2(OH)2(TBC[4])2(DMF)6]·2MeOH (1), [MnIII 2MnII 2(OH)2(TBC[4])2(DMF)4(H2O)2]·4MeOH·2DMF (2), [MnIII 2MnII 2(OH)2(TBC[4])2(DMF)6]·2.8MeOH (3), [MnIII 2MnII 2(OH)2(TBC[4])2(DMF)4(EtOH)(H2O)] (4), [MnIII 2MnII 2(OH)2(TBC[4])2(DMSO)6]·2MeOH·2DMSO (5) , [MnIII 2MnII 2(OH)2(TBC[4])2(DMSO)6] (6) and [MnIII 2MnII 2(OH)2(C[4])2(MeOH)6]·4MeOH (7). Variation in the alkyl groups present at the upper-rim of the cone allows for the expression of a degree of control over the self-assembly of these SMM building blocks, whilst retaining the general magnetic properties. The presence of various different ligands around the periphery of the magnetic core has some effect over the extended self-assembly of these SMMs. Chapter three describes how the combination of complementary cluster ligands; sodium phenylphosphinate and the N,O-chelate 2-(hydroxy-methyl)pyridine (hmpH) with TBC[4] results in the formation of two new calixarene-supported clusters. This being an unusual [MnIIIMnII]2 dimer of dimers [MnIIIMnII(O2P(H)Ph)(DMF)2(MeOH)2]2 (8) and a ferromagnetic [Mn5] cage that displays the characteristic bonding modes of each support [MnIII 3MnII 2(OH)2(TBC[4])2(hmp)2(DMF)6](TBC[4]-H)·xDMF ·xH2O (9). Chapter four details how using oxacalix[3]arenes can tune the nature of the metal binding site, by introduction of ≥ 1 ethereal bridge. This results in Mn(II) rather than Mn(III) bonding in the phenolic pocket, and that these components self-assemble with additional Mn(II) and Mn(III) ions to form a [Mn10] supertetrahedron with an unusual oxidation state distribution, [MnII 6MnIII 4O4(TBOC[3])4(Cl)4(DMF)3]∙3.3H2O ∙ 1.5DMF (10). Chapter five introduces a family of lanthanide complexes formed using TBC[8]. Variation in the experimental conditions employed in the reaction of TBC[8] with lanthanide salts (LnX3) provides access to Ln1, Ln2, Ln4, Ln5, Ln6, Ln7 and Ln8 complexes, [Gd(TBC[8]-2H)Cl(DMSO)4]·MeCN·H2O·(DMSO)2·hex (11), [CeIV 4(TBC[8]-6H)2(μ3- O)2(DMF)4]·(DMF)5·hex·MeCN (12), [TbIII 5(TBC[8]-5H)(μ4-O)(μ3- OH)4Cl(DMSO)8(H2O)3]Cl3·(DMSO)2(hex)2 (13), [CeIV 6(TBC[8]-6H)2(μ4-O)2(μ2-OMe)4(μ2- O)2(DMF)4]·(DMF)6·hex (14), [Dy7(TBC[8]-7H)(TBC[8]-6H)(μ4-O)2(μ3-OH)2(μ2- OH)2(DMF)9]·(DMF)3 (15) and [Gd8(TBC[8]-7H)2(μ4-CO3)2(μ5-CO3)2(μ2-HCO2)2(DMF)8] (16), with all polymetallic clusters containing the common bi-nuclear lanthanide fragment. Closer inspection of the structures of the polymetallic clusters reveals that all but one (Ln8) are in fact based on metal octahedra or the building blocks of octahedra.
9
Khan, Latif Ullah. "Nanomateriais ópticos e magnéticos contendo matrizes de Fe3O4 e SiO2 funcionalizadas com calixareno e complexos de terras raras." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-20072015-151110/.
Full textAbstract:
Neste trabalho são investigados o designer e a fabricação nanomateriais magnéticos e luminescentes sofisticados bifuncionais baseados em Fe3O4 e complexos de RE3+. Portanto, novos nanomateriais Fe3O4@calix-Eu(TTA) e Fe3O4@calix-Tb(ACAC) emissores vermelho e verde superparamagnéticos foram preparados pelo método one-pot. Neste caso, o ligante calixareno quimicamente modicado como surfactantes para estabilizar as nanopartículas de Fe3O4. O ligante calixareno proporciona uma superfície quimicamente modificada e estabilidade coloidal das nanopartículas magnetitas. Consequentemente, as nanopartículas funcionalizadas (Fe3O4@calix) foram coordenadas aos íons TR3+ por meio da síntese one-pot, usando ligantes TTA e ACAC como sensibilizadores (efeito antena) para produzir nanofósforos altamente luminescentes. Além do mais, nanocompósitos bifuncionais óptico e magnético Fe3O4@SiO2-TTA-Eu(L), L: TTA, TC, AB e AMB bem como Fe3O4@SiO2-TTA-Tb(AB ou AMB) foram também preparados por meio de um protocolo de múltiplas etapas, utilizando as nanopartículas Fe3O4 como precursoras. Elas foram modificas com camadas de sílica, usando o método Stöber modificado e ligados com complexos de TR3+ para produzir nanocompósitos luminescentes e magnéticos. As técnicas de difração de raios X pelo método do pó (XPD), Espalhamento de Raios-X a baixo ângulo (SAXS), microscopia eletrônica de transmissão (TEM) e microscopia de eletrônica de varredura (MEV) foram utilizas para determinar as estruturas, morfologias, distribuições de tamanhos e monodispersividade dos materiais sintetizados. Estes novos nanomateriais bifuncionais Fe3O4@calix-Eu(TTA), Fe3O4@calix-Tb(ACAC), Fe3O4@SiO2-TTA-Eu(L) e Fe3O4@SiO2-TTA-Tb(AB ou AMB) apresentam propriedades fotônicas e superparamagnéticas muito interessantes. As propriedades magnéticas (ZFC/FC e M-H) obtidas nas temperaturas de 2, 5 e 300 K foram investigadas a fim de obter informações sobre o efeito da cristalinidade na magnetização de saturação e das temperaturas de bloqueios. Também foram estudadas a influência dos íons TR3+ sobre a magnetização dos nanomateriais. Apesar da magnetita atuar como um forte supressor de luminescência, as camadas do ligante calixareno modificado e da sílica sobre as nanopartículas de Fe3O4 compensam esta desvantagem. Do mesmo modo foi considerada a discussão sobre a transferência de energia intramolecular do estado tripleto T1 dos ligantes TTA e ACAC para os níveis excitados dos íons Eu3+ e Tb3+ nos nanomateriais Fe3O4@calix-Eu(TTA) e Fe3O4@calix-Tb(ACAC). As eficiências quânticas de emissão (η) dos compostos Fe3O4@calix-Eu(TTA) e Fe3O4@SiO2-TTA-Eu(L) foram calculadas e discutidas, bem como suas características estruturais baseadas nos níveis de energia e parâmetros de intensidades experimentais dos sistemas contendo o íon Eu3+. Estes novos nanomateriais podem atuar como camadas emissores vermelha e verde para dispositivos moleculares conversores de luz e magnéticos (MLCMDs).The design and fabrication of sophisticated bifunctional luminescent and magnetic nanomaterials based on Fe3O4 and RE3+ complexes are sought for. Accordingly, novel red-green emitting superparamagnetic Fe3O4@calix-Eu(TTA) and Fe3O4@calix-Tb(ACAC) nanomaterials were prepared through on-pot method. In this regard, the chemically modified calixarene ligand was used as a surfactant to stabilize the Fe3O4 nanoparticles. The calixarene ligand provides colloidal stability and chemically modifiable surface to the magnetite nanoparticles. Thus, this ligand functionalized Fe3O4@calix nanoparticles were further coordinated to the RE3+ ions via one-pot synthesis, using TTA and ACAC ligands as sensitizers (antenna effect) to produce highly luminescent nanophosphors. In addition, bifunctional optical and magnetic Fe3O4@SiO2-TTA-Eu(L), L: TTA, TC, AB and AMB as well as Fe3O4@SiO2-TTA-Tb(AB or AMB) nanocomposites were also synthesized through multistep synthetic protocol, utilizing Fe3O4 nanoparticles as precursors. They were modified with silica shell, using modified Stöber method and further grafted with RE3+ complexes to produce the luminescent and magnetic nanocomposites. The X-ray powder diffraction (XPD), small angle x-ray scattering (SAXS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques were used to determine the structures, morphologies, size distribution and monodispersity of the synthesized materials. These novel Fe3O4@calix-Eu(TTA) and Fe3O4@calix-Tb(ACAC) as well as Fe3O4@SiO2-TTA-Eu(L) and Fe3O4@SiO2-TTA-Tb(AB or AMB) magnetic luminescent nanomaterials show interesting superparamagnetic and photonic properties. The magnetic properties (M-H and ZFC/FC measurements) at temperatures of 2, 5 and 300 K were explored in order to investigate the extent of coating and crystalinity effect on the saturation magnetization and blocking temperatures. The influence of the RE3+ ions on the magnetization of the optical and magnetic nanomaterials was also studied. Even though magnetite is a strong luminescence quencher, the coating of the Fe3O4 nanoparticles with synthetically modified calixarene ligand (calix) and silica shell have overcome this difficulty. Moreover, the intramolecular energy transfer from the T1 excited triplet states of TTA and ACAC ligands to the emitting levels of Eu3+ and Tb3+ in the Fe3O4@calix-Eu(TTA) and Fe3O4@calix-Tb(ACAC) nanomaterials are discussed. The emission quantum efficiencies (η) for the Fe3O4@calix-Eu(TTA) and Fe3O4@SiO2-TTA-Eu(L) nanomaterials are also calculated and discussed, as well as the structural features based on the energy levels and experimental intensity parameters, in the case of the Eu3+ ion. These novel nanomaterials may act as the emitting layer for the red and green light for magnetic and light converting molecular devices (MLCMDs).
10
Jensen, Svend Borup. "Schiff base calixarenes." Thesis, University of the West of Scotland, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246345.
Full textAbstract:
Four different synthetic routes to the sub-target, the p-tert-butylcalix[4lethylamine (6a) from thep-tert-butylcalix[4]arene (1a) have been examined. The best one was a 5-step synthesis, which gave an overall yield of65%. p-tert-Butylcalix[6]ethylamine (6b) and p-tert-butylcalix[8]ethylamine (6c) were synthesised from their respective p-tertbutylcalixarenes by the same route as the p-tert-butylcalix[4]ethylamine (6a). The three different amines (compound (6a), (6b) and (6c)) were used in 14 different Schiff -base type reactions which resulted in six Schiff-base compounds which were fully characterised by NMR, IR, FAB-ms and UV-vis. Insertion studies of the Schiff-base compounds along with template synthesis of the Schiff-base compounds were also attempted. The uptake of solid metal salt by the Schiff-base compounds in solution was examined by UV-vis spectroscopy. One of the Schiff -base compounds synthesised was the ferrocenecarboxaldehyde Schiff-base calix[4]arene (22a). An electrochemical analysis of this compound was undertaken to assess whether if it could be used as a sensor for metal ions. Molecular modelling of the Schiff-base compound and a crystal structure ofp-tert-butylcalix[4]ethylnitrile (8) are also presented in the thesis
11
Goulden, Alistair John. "Anion recognition by novel calixarene receptors." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240479.
Full text
12
Byrne, Declan J. "Novel calixarene receptors for ion complexation." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287294.
Full text
13
Roka, Eszter. "Biocompatibility evaluation and synthesis of macrocyclic compounds." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1027/document.
Full textAbstract:
La faible solubilité de certains médicaments cause des problèmes majeurs dans les formulations pharmaceutiques, puisque la solubilité dans l'eau est un critère indispensable pour la biodisponibilité. Les composés macrocycliques tels que les CDs et les calixarènes ont une cavité relativement hydrophobe, leur permettant ainsi d'encapsuler de nombreuses molécules. Les CDs ont déjà été utilisées comme excipients pharmaceutiques pour l'amélioration de la solubilité. La structure de ces macrocycles permet d'effectuer de nombreuses modifications, qui causent des changements tant au niveau de leurs caractéristiques physico-chimiques que sur leurs effets sur les organismes vivants. Ainsi, l'évaluation de la biocompatibilité de ces dérivés est primordiale en vue de leur utilisation en pharmacie. Puisque l'étude de la biocompatibilité de plusieurs dérivés de β-CD a déjà été étudiée, l'objectif de cette recherche était d'étendre ces expériences à des dérivés de l'α-CD qui sont disponibles dans le commerce. Nous nous sommes intéressés aux relations entre structure et toxicité. Ainsi les dérivés alkyl éther d'α-CD, avec des chaînes alkyle de longueur croissante et substitués sur différentes positions, ont été synthétisés et leur toxicité étudiée. Les para-sulphonato-calix[n]-arènes quant à eux, ont souvent été étudiés et ont montré une forte capacité à complexer de nombreux médicaments. Ils ont aussi démontré une activité biologique polyvalente. Néanmoins, leurs effets sur le mécanisme de transport paracellulaire n'a jamais été évaluée. Les tests de viabilité cellulaire et d'hémolyse nous ont permis d'une part de classer les α-CDs et de choisir les dérivés les plus sûrs, et d'autre part de comparer leur effets toxiques dans des systèmes différents. La comparaison des α- et ß-CDs portant les mêmes modifications chimiques nous a montré l'importance du nombre d'unités de construction. Le rapport entre l'effet cytotoxique et le nombre de groupes hydroxyles libres est également très important. Les dérivés portant de longues chaînes alkyles possèdent une faible solubilité, ce qui nous a conduits vers d'autres modifications chimiques : la sulfonation de ces derniers dérivés semble avoir un impact bénéfique sur la biocompatibilité de CDs. Elle a aussi amélioré la solubilité des calixarènes. Les calix[4] et [8]arène sulphonates ont prouvé leur effet positif sur l'absorption paracellulaire, tandis que le calix[6]arène sulphonate n'a pas eu d'effet similaire. Notre recherche conclut que les changements structurels sur les anneaux macrocycliques peuvent avoir un impact majeur sur la biocompatibilité. Comme les possibilités de modification sont pratiquement illimitées, l'évaluation de la structure et de l'activité est indispensable pour faciliter les choix les plus sûrs dans les applications pharmaceutiques à venirThe low solubility of drug candidates cause a major problem in pharmaceutical formulations, as the aqueous solubility is an indispensable criterion for appropriate bioavailability. Macrocyclic compounds possess a relatively hydrophobic cavity, which is suitable for guest molecule inclusion. Cyclodextrins and calixarenes are widely studied organic host-compounds, and CDs have already been used as pharmaceutical excipients for solubility enhancement. The macrocycles’ chemical structure allows their versatile modification, which eventuates changes not only in physicochemical characteristics, but in their effects on living organisms, as well. Thus, the biocompatibility evaluation of the derivatives is fundamental. Owing to the already performed assessment of numerous β-CD derivatives’ biocompatibility, the aim of this research was to extend these experiments to commercially available α-CDs. They have been used less frequently, however several derivatives, which have not been tested yet in vitro, have the possibility of future pharmaceutical use. Their importance is also certified by their benefits in nanoparticle formation. We have been interested in concrete structure-toxicity correlations, thus alkyl ether α-CD derivatives were synthetized bearing increasing length alkyl chains, in different positions. Para-sulphonato-calix[n]-arenes have already been widely examined due to their efficient drug complexation and versatile biological activity, however, their effects on paracellular transport mechanism have not been evaluated until now.The cell viability and hemolysis tests have allowed us to rank the α-CDs and to choose the safest derivatives, also to compare their toxic effects in different systems. The comparison of α- and β-CDs bearing the same chemical modifications highlighted the importance of the number of building units. Important information has been evaluated regarding the connection between the cytotoxic effect and the number of free hydroxyl groups. Derivatives with long alkyl chains possess low solubility, which led us towards further chemical modifications. Sulfonation seemed to have beneficial impact on the biocompatibility. Sulfonation also improved the solubility of calixarenes. C4S and C8S proved their positive effect on paracellular absorption in a non-toxic concentration range, however C6S had no similar effect, thus their behaviour in in vitro absorption model system arose forward-looking questions.Our research concludes, that the structural changes on the macrocyclic rings may have major impact on the biocompatibility. As the modification possibilities are practically unlimited, the evaluation of structure and activity cannot be avoided, facilitating the safest choice for further pharmaceutical use
A gyógyszerhatóanyagok rossz vízoldékonysága nagy kihívást jelent formulálásuk során, ugyanis a vízoldékonyság elengedhetetlen feltétele a megfelelő biohasznosulásnak. A makrociklusos vegyületek belső ürege viszonylag hidrofób, ez alkalmassá teszi őket vendégmolekulákkal való komplexképzésre. A ciklodextrinek és kalixarének széles körben tanulmányozott vegyületek, egyes CD-ek bejegyzett oldékonyságnövelő segédanyagok. A makrociklusok felépítése számos kémiai módosításra ad lehetőséget, amelyek nem csupán a fiziko-kémiai tulajdonságok változását eredményezik, hanem az élő organizmusokra kifejtett hatásokat is módosítják. Ezen származékok biokompatibilitás vizsgálata tehát elengedhetetlen. Számos β-CD származék biokompatibilitása ismert már, így kutatásunk célul tűzte ki ezen vizsgálatok α-CD-ekre történő kiterjesztését. Az α-CD-ek alkalmazása ritkább, azonban vannak származékok, amelyek in vitro vizsgálata még nem történt meg, de jelentőségük a nanopartikulum-képzésben már igazolt. A szerkezet-toxicitás összefüggések feltárása érdekében olyan alkil-éter CD származékokat szintetizáltunk, amelyek növekvő szénatomszámú alkil-csoportokkal rendelkeznek, eltérő pozíciókban. A para-szulfonáto-kalix[n]aréneket hatóanyag-komplexáló tulajdonságuk, valamint sokoldalú biológiai aktivitásuk miatt széles körben tanulmányozták már, azonban a paracelluláris anyagtranszportra gyakorolt hatásuk ezidáig még nem volt ismert. A sejtéletképességi és hemolízis vizsgálatok hozzásegítettek az egyes α-CD-ek rangsorolásához, továbbá a vegyületek különböző rendszerekben mért toxikussága is összevethetővé vált. A megegyező kémiai módosításokon átesett α- és β-CD-ek biokompatibilitása rávilágított a CD-gyűrű mértének jelentőségére. Egyértelmű összefüggést fedeztünk fel a toxicitás és a szabad hidroxil-csoportok száma között. A hosszú alkil-csoporttal rendelkező CD-ek rossz oldékonysága további kémiai módosításokat tett szükségszerűvé; a szulfát csoportok jelenléte jótékony hatással volt az oldhatóságra, és a citotoxicitásra is. A szulfatálás a kalixarének oldékonyságát is növelte. A C4S és C8S vegyületek növelték a paracelluláris felszívódás mértékét szubtoxikus koncentrációban, azonban a C6S nem mutatott hasonló hatást. Ezen eredmények további kérdéseket vetnek fel a pontos hatásmechanizmusról. Eredményeink rávilágítanak a makrociklusok szerkezetének és biokompatibilitásának összefüggéseire, valamint ezen ismeretek fontosságára annak érdekében, hogy minden formulációban a legbiztonságosabb segédanyagok legyenek alkalmazhatóak
14
Grives, Sophie. "Etude de la toxicité in vitro et de l'efficacité ex vivo et in vivo de formes galéniques de calixarène développées pour le traitement des contaminations cutanées dues à des composés d'uranium." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA114815/document.
Full textAbstract:
En cas de contamination cutanée radiologique par des composés d’uranium, les seuls traitements actuellement employés consistent en un rinçage de la zone contaminée par de l’eau et des détergents, ou par une solution de sel calcique de l’acide diéthylène-triamine-pentaacétique (Ca-DTPA). Ces derniers ne sont cependant pas efficaces vis-à-vis de l'uranium. De plus, en l'absence de traitement d'urgence, le passage transcutané de ce radionucléide est rapide, et induit une exposition interne après sa distribution dans l’organisme par le biais de la circulation sanguine. Une partie de l'uranium ainsi biodisponible est alors stockée dans les organes cibles que sont principalement les reins et le squelette, où ses effets toxiques se manifestent. C'est pourquoi une formulation topique consistant en une nanoémulsion huile dans eau, incorporant des molécules de calixarène tricarboxylique en tant qu'agent chélatant spécifique de l'uranium, a été initialement développée. Les travaux menés dans le cadre de cette thèse visent à évaluer l'efficacité de décontamination ex vivo et in vivo de ce nouveau traitement d'urgence à la fois sur peaux intactes et sur peaux lésées superficiellement. Pour cela, le modèle d'excoriation a été utilisé. Des modèles de lésions reproductibles ont également été mis en place afin de mimer des incisions par micro-piqûres et microcoupures. Ces études démontrent que la nanoémulsion de calixarène pourrait constituer un traitement de décontamination efficace, moins agressif que l’emploi de l’eau savonneuse actuellement employée. Sa potentielle toxicité cutanée a également été évaluée in vitro par l'utilisation d'épiderme humain reconstitué, combinée à trois différents tests de toxicité (MTT, LDH et IL-1-α). Dans le cadre de ces études, il a ainsi été démontré que la nanoémulsion de calixarène n’induit pas de toxicité cutanée, même après un temps de contact prolongé jusqu'à 24 hIn case of radiological skin contamination by uranium compounds, the only treatments currently available consist in rinsing the contaminated skin area with water and detergent, or with a calcium salt of diethylene triamine pentaacetic acid (Ca-DTPA) solution. However, these procedures are not specific and no efficient treatment for cutaneous contamination due to uranium exists. In the absence of such treatments, uranium diffusion through the skin is fast, inducing an internal exposure after its distribution inside the body through the bloodstream. One part of the bioavalaible uranium is uptaken in target organs which are the kidneys and the skeleton, where its toxic effects occur. Therefore a topical formulation consisting of an oil-in-water nanoemulsion incorporating a tricarboxylic calixarene molecule, as a specific chelating agent for uranium, was previously developed. The work achieved in this thesis aimed at evaluating the ex vivo and in vivo decontamination efficiency of this new emergency treatment on intact and superficially wounded skin. For this purpose, skin excoriation model was used. Reproducible models of superficial wounds consisting of micro-cuts and micro-punctures were also developed in order to evaluate the efficiency of the nanoemulsion on physical wounds such as incisions. These studies showed that the calixarene nanoemulsion could be an efficient decontaminant treatment, less aggressive than using the current treatment: soaped water. Its potential cutaneous toxicity was evaluated on in vitro reconstructed human epidermis using three different toxicity tests (MTT, LDH and IL-1-α). These studies demonstrated that the calixarene nanoemulsion did not induce skin toxicity even after 24 h of exposure time
15
Qureshi, Naseem. "Calixarene and coordination complex hosts for anions." Thesis, Durham University, 2009. http://etheses.dur.ac.uk/18/.
Full textAbstract:
My Ph.D research is mainly based on ‘calixarene and coordination complex hosts for anion’. The research is to make synthetic chloride ion channels for possible treatment of cystic fibrosis. Our approach is based on derivatives of larger calix[n]arenes. Calixarenes are chalice-shaped molecules that form readily under base catalyzed-condensation of tert-butyl phenol with formaldehyde. We have synthesized calixarenes which were tuned at the lower rim with bromo alkyl nitrile and reduced followed by reaction with a series of different isocyanates bearing fluorescent functional groups capable of binding and sensing chloride and nitrate. We are also interested how the host ligand binds with metal anions in solution and solid state chemistry. We synthesised simple pyridyl urea ligands and isomorphs. Their anion binding studies are discussed in terms of solid state and solution chemistry. Solid state structures based on silver and copper metal forming contact ion pairs with series of anions like nitrate, chloride, bromide, trifluoroacetate and boron tetrafluoride. Their solution based anion binding studies were performed and control titration results show that these hosts bind anions in a one to one fashion which was confirmed with solid state structures. An interesting aspect is that 2-ureidopyridine ligand exists in four different anhydrous crystal forms (I – IV0), which can be crystallized by several techniques. It was found that forms I and II only crystallize without another polymorph from methanol solution or in presence of inorganic salts. Thermoanalysis shows that all the modifications melt without previous transition and applying the heat of fusion rule proves this system to be completely monotropic. The crystal structures show that the molecule forms one intramolecular and two intermolecular hydrogen bonds to give S(6) and dimeric R (8) graph synthons in all four structures. However packing arrangements differ strikingly and since the hydrogen-bonding arrangement is the same for all the four forms, the differences in energy measured by thermoanalytical methods can only be caused by the different packing arrangements involving combinations of the weaker interactions, with the CH.¼S contacts being among the obvious differences. Thus, this system is a clear example in which the presence of robust, reproducible hydrogen bonded synthons does not lead to any control or predictability of polymorphic form.
16
Marenco, Claudia. "Calixarene monolayers as surface-enhanced raman sensors." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287632.
Full text
17
Funck, M. "Research towards novel immunotherapeutic vectors : calixarene scaffolds." Thesis, Nottingham Trent University, 2011. http://irep.ntu.ac.uk/id/eprint/56/.
Full textAbstract:
The aim of this project was to generate a new type of therapeutic delivery system and immunogenic vector, based on calixarenes, that is able to not only deliver immunogenic peptide but also act as a potential cancer vaccine. The introduction presents calixarenes derivatives in the context of supramolecular chemistry. Their properties on the nanoscale allow them to be potential adjuvants for cancer immunotherapeutics. The synthetic study of these materials presented in Chapter II compares traditional synthetic protocols and a new greener approach utilising microwave irradiation. Initial studies in this area concentrate on alkyl-footed derivatives of both the resorcin[4]arene and pyrogallol[4]arene macrocycles but have also been expanded to the previously problematic aromatic derivatives. This microwave method has been optimised to produce the rccc diastereoisomer for both the alkyl and aromatic derivatives, showing that the nature of the substituent on the pendant chains does not have a great effect on the conformation using this green protocol. The solution and solid state studies of these new aromatic pyrogallol[4]arene macrocycles, in the rccc cone conformation, have been investigated and demonstrate their future potential application in hydrogen storage. The synthesis of polar analogues, described in Chapter III, was achieved by functionalising the pendant chains with polar groups, including amines, alcohols and carboxylic acids. The importance of the solvent in the crystallisation process is highlighted by single crystal X-ray diffraction study, showing that it can act as templating agent or guest. Access to polar footed calixarenes has enabled the project to investigate their potential to link bioactive therapeutics including amino acids and peptides, towards nano-vectors exposed in Chapter IV. The traditional synthesis in solution was challenging due to purification issues, and only succeeded in the attachment of three trialanines. The method was therefore tuned towards solid phase synthesis, which opened up to the new development of Merrifield resin functionalised with calixarenes. As the macrocycle will be considered for immunisation in the future, the lead macrocycle from this study have been screened for potential downstream biological applications. Preliminary studies, including haemolytic properties and cytotoxicity studies did not show any toxicity at the workable concentrations.
18
Lemée, Frédéric. "Composés polyioniques contraints bioactifs libres et supportés : accès à de nouveaux matériaux antibactériens." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0047/document.
Full textAbstract:
La mise au point de nouveaux matériaux possédant des propriétés antibactériennes est un sujet intéressant le monde médical et environnemental. Pour cela, les polymères commerciaux de Merrifield et de Wang-benzaldéhyde ont été modifiés par greffage de motifs calixarèniques polycationiques antibactériens inspirés des travaux du laboratoire et désignés pour interagir avec la surface bactérienne chargée négativement. Ces calixarènes ont été modifiés sur la partie basse, de façon contrôlée, par incorporation d'un groupe espaceur fonctionnel permettant d'accéder à un greffage ciblé du polymère. Nous avons en premier lieu évalué plusieurs types de fonctionnalités introduites sur le calixarène, permettant la fixation de ces motifs sur le support polymérique. Ainsi une amination réductrice a été choisie pour l’ancrage sur la résine de Wang-benzaldéhyde, tandis qu’un point d’ancrage de type pyridinium, pour la résine de Merrifield, a retenu notre attention et s'est avéré être un excellent candidat pour le greffage des calixarènes. La validité de ce point d’ancrage pyridinium a pu être vérifiée par l’incorporation d’une sonde fluorescente (pyrène) et caractérisée par fluorescence à l’état solide, par spectroscopie infrarouge et analyse élémentaire, ces deux dernières étant appliquées à l'ensemble des polymères préparés par la suite. Au travers d'une étude de capture–relargage en milieu aqueux de deux antibiotiques carboxyliques (type quinolone et ß-lactame) le polymère pyridinium modèle, sans calixarène, a montré tout son intérêt, face à la cholestyramine (Questran®) ou à l'Amberlite IRA-400, en tant que résine échangeuse d'anions et pouvant mener à une utilisation en tant que dépolluant/décontaminant. En amont des études antibactériennes de ces nouveaux matériaux nous avons cherché à quantifier la capacité du matériau à retenir/séquestrer des bactéries. L’électrophorèse capillaire, méthode analytique rapide et sensible, s’est présentée comme une solution adéquate. Sur le modèle E. coli., les résines polycationiques synthétisées ont été évaluées en tant que séquestrants en milieu aqueux. Les résultats obtenus prouvent l’efficacité de certaines d’entre elles; la capture a finalement été confirmée par microscopie de fluorescence confocale. Le nombre de bactéries fixées à la surface du matériau a pu être visuellement évaluéDevelopment of new materials with antibacterial properties is a major concern in medical and environmental world. It’s for that reason that, Merrifield and Wang commercial polymers were modified by grafting polycationic calixarenic sub-units inspired by laboratory work and designed to interact with negatively charged bacterial surface. Those calixarenes were modified on the lower part, in a controlled manner, by the incorporation of a functional spacer group leading to a targeted grafting of the polymer. We have, at first, evaluated several kinds of functionalities introduced on the calixarene, giving us the opportunity to graft them on the polymeric support. Like this, a reductive amination was chosen to anchor the Wang-benzaldehyde resin, whereas a pyridinium anchoring point was pointed out as a very good candidate for the grafting of calixarenes. The validation of this pyridinium anchoring point was checked by incorporation of a fluorescent probe (pyrene) and characterized by solid state fluorescence, by infrared spectroscopy, those two lasts analysis were applied for all the other grafted polymers grafted after that. Through a capture-release study in aqueous media of two carboxylic antibiotics (quinolone and ß–lactame kind), the pyridinium polymer model, without calixarène, showed his interest faced to Cholestyramine (Questran®) or Amberlite IRA-400, as an anion exchange resin and leading to depoluting/decontamination applications. Before antibacterial studies of thoses new materials, we wanted to find a way to quantify the material capacity to catch/hold bacteria. Capillary electrophoresis, rapid and sensitive analytical method, appeared as a perfect solution. Using E. coli model, synthesized polycationic resins were evaluated as sequestering agent in aqueous media. Results obtained prove the efficiency of some of them; capture was finally confirmed by confocal fluorescent microscopy. The number of bacteria fixed by material surface could be visually evaluated
19
Klaes, Michael. "Chirale Calixarene als Bausteine in der Supramolekularen Chemie." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=978213807.
Full text
20
Concilio, Gerardo. "Cavity Filling and Chirality Effects in Calixarene Threading." Doctoral thesis, Universita degli studi di Salerno, 2016. http://hdl.handle.net/10556/2221.
Full textAbstract:
2014 - 2015In 2010, the Prof. Neri’s group showed that the calix[6]arene hosts were able to recognize dialkylammonium axles when they were coupled with the weakly coordinating Tetrakis[3,5 bis(triFluoromethyl)Phenyl]Borate (TFPB−) “superweak anion” that gives very loose ion-pairs with dialkylammonium cations in solution.1 These interpenetrated structures have been defined in supramolecular chemistry as pseudorotaxane and can be considered as synthetic precursors of catenane and rotaxane architectures2 which have showed appealing properties as molecular machines3. Interestingly, the threading of directional alkylbenzylammonium guests with calix[6]arene wheels, led to the stereopreference for the endo-alkyl complexation over the endo-benzyl one and this observed stereo-selectivity brought to the definition of the so called “endo-alkyl rule”4. On these basis we have studied the recognition abilities of calix[6]arene derivatives toward alkylbenzylammonium guests bearing aliphatic chains with different shape and length. In particular, we studied the validity of the endo-alkyl rule with alkylbenzylammonium axles bearing alkyl chains with different lengths and using guests bearing branched alkyl chains. Then the thesis work has been extended to the threading of chiral systems. Special attention was paid to the possibility of obtaining, after threading, the chiral recognition of chiral alkylbenzylammonium ions using chiral calix[6]arene derivatives. The investigation techniques chosen for this purpose have been NMR spectroscopy and Mass Spectrometry by means of the "Enantiomer Labelled Method". Finally the search for new and attractive potential chiral hosts resulted in the application of the "p-bromodienone route" for the first time on calix[6]arene derivatives5 and the study of the optical and electronic properties of inherently chiral resorcin[4]arene derivatives. [edited by author]
XIV n.s.
21
Makha, Mohamed 1965. "Novel sulfonated extended arm calixarenes." Monash University, School of Chemistry, 2001. http://arrow.monash.edu.au/hdl/1959.1/8295.
Full text
22
Moran, Mary B. "Novel calixarenes for cation complexation." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238993.
Full text
23
Iqbal, Khayzuran Sadrudine Jamal. "Transmembrane ion transport by calixarenes." Thesis, University of Brighton, 2011. https://research.brighton.ac.uk/en/studentTheses/8444b32d-9ab4-4e13-9cd9-29d9281ab15c.
Full textAbstract:
Regulation of transmembrane ion transport is a vital aspect in the maintenance of a healthy organism. To understand how this highly selective process occurs, how it can become impaired and how impairment may be treated, model compounds are useful tools. Several systems are presently being explored but one of the most widely applicable combines a rigid macrocycle, capable of size-based ion recognition, with membrane spanning substituents that allow the target ions to transverse a phospholipid bilayer. The calixarene class of macrocycles is ideally suited to this task. Previous work had shown that oxacalix[3]arenes could act as models for the filters in natural transmembrane ion channels. Nitrogen-containing analogues of these calixarenes, azacalix[3]arenes, were investigated with a view to constructing a chloride transporting system. Synthetic difficulties encountered when introducing lower rim substitutents precluded the use of azacalix[3]arenes and attention turned to 4-t-butylcalix[n]arenes. 4-t-Butylcalix[4]- and [6]arenes were derivatised with a commercial, membrane disrupting surfactant, Triton X-IOO®, forming compounds designed to form lipid bilayer-spanning, channel-like structures. The ion transporting ability of these, and other bilayer-spanning O-substituted calixarene derivatives, was determined by planar bilayer electrophysiological methods. Results showed that this modular approach to artificial ion channel construction was successful; calixarene derivatives formed transmembrane channels that allowed sodium ions to pass through but not the larger potassium ions.
24
Nachtigall, Francine Furtado. "Interações entre calixarenos e aminas." Florianópolis, SC, 1997. http://repositorio.ufsc.br/xmlui/handle/123456789/77023.
Full textAbstract:
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas.Made available in DSpace on 2012-10-17T00:05:38Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T22:03:43Z : No. of bitstreams: 1 172556.pdf: 4599960 bytes, checksum: 0574b8de1f3b81cd40d81fbaa105a8e0 (MD5)
A interação de aminas com calixarenos em acetonitrila foi estudada através de titulações condutivimétricas e espectrofotométricas e espectroscopia de ressonância magnética nuclear de próton e carbono-13. Foi observada a ocorrência de transferência de próton entre calix[4]areno e aminas alifáticas e os dados condutivimétricos mostraram que o sal formado existe num equilíbrio entre íons separados e pares iônicos. As constantes de associação dos íons foram determinadas condutivimetricamente, obtendo-se valores na ordem de 102 M-1. Os valores das constantes de equilíbrio da etapa de transferência de próton obtidos são compatíveis com as basicidades das aminas em acetonitrila. Os valores de deslocamento químico dos prótons dos íons amônio obtidos na presença de calix[4]areno são semelhantes aos obtidos na presença de ácido trifluoracético, indicando que os complexos formados são do tipo exo-cálix. Através de espectrofotometria de UV observa-se que para calix[4]areno e para p-terc-butilcalix[6]areno com piperidina e terc-butilamina ocorre apenas a transferência de um próton para uma amina. Para p-terc-butilcalix[6]areno com n-hexilamina e para calix[6]areno, mediante a adição de excesso de amina, a desprotonação da segunda hidroxila fenólica depende principalmente do volume do substituinte ligado ao nitrogênio da amina, o que é atribuído à formação de complexo do diânion com pelo menos um íon amônio, mesmo a baixa concentração. Dados de 1H- RMN mostram que o complexo formado é endo-calix, com o amônio imerso até o carbono b na cavidade do calixareno e que este se encontra na conformação 1,2,3-alternado.
25
Lazzarotto, Márcio. "Reações de calixarenos com biomoléculas." Florianópolis, SC, 1997. http://repositorio.ufsc.br/xmlui/handle/123456789/77034.
Full textAbstract:
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas.Made available in DSpace on 2012-10-17T00:12:05Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T21:29:14Z : No. of bitstreams: 1 172561.pdf: 8515203 bytes, checksum: 4df94a6fb3cc5f463b73a5e080dd28f6 (MD5)
Calixarenos são uma classe de moléculas que apresentam uma cavidade hidrofóbica e podem reconhecer e transportar moléculas neutras e metais. Derivados de calixarenos com biomoléculas foram sintetizados e suas conformações determinadas. As biomoléculas foram ligadas formando éteres, ésteres e amidas de biomoléculas, agregando em alguns casos quiralidade à estrutura do calixareno. Na reação do para-terc-butilcalix[4]areno com o O-tosil-S-(+)-lactato de etila, em K2CO3/acetona, obteve-se apenas o produto bis-substituído na conformação cone com inversão do centro assimétrico. Tentativas posteriores para reagir o produto da reação anterior com BrCH2CO2Me falharam. Os espectros de RMN de 1H e 13C mostram que o centro assimétrico desdobra os sinais dos hidrogênios metilênicos e aromáticos e os carbonos aromáticos. A determinação estrutural através de difratometria de raio-X em monocristais do calix-lactato mostrou a existência de duas moléculas por cela de acordo com a conformação cone presumida por RMN; onde uma etila de uma molécula encontra-se imersa na cavidade da outra. O éster foi hidrolisado, obtendo o derivado lático sem racemização, observando variação no sinal de a. Sintetizaram-se derivados de para-terc-butilcalix[4] areno com N-Ftaloil-aminoácidos (GLI, ALA, b-ALA, PHE, LEU e N-Ft-ORN) a partir dos cloretos em Et3N/CH2Cl2, obtendo em todos os casos os produtos de bis-substituição com conformação alternado 1,3. No caso da glicina, testou-se AlCl3 como catalisador da reação, obtendo o mesmo resultado. Com a variação dos substituintes ocorrem pequenas variações na estrutura, detectadas através de IV e RMN. Nos derivados com carbonos assimétricos, os hidrogênios aromáticos e metilênicos ligados são diastereotópicos. O produto com N-Ft-ala racemiza completamente, gerando dois diastereoisômeros em igual proporção e os produtos com outros aminoácidos quirais sofreram racemização parcial. Amidas de calixarenos com ésteres metílicos de aminoácidos (gli, L-ala, L-asp-Me) foram sintetizadas a partir de cloro-carboxi-metano-para-terc-butilcalix[4]arenos em conformação cone. Determinaram-se as porcentagens e as constantes de extração de metais alcalinos, alcalino-terrosos e amônio pelo produto com glicinato de metila e aspartato de metila via espectrofotometria de ultravioleta, e os valores encontrados foram baixos, com valores entre 2 a 3 % de extração , com exceção do sódio com o tetrakis-L-aspartato de metila-para-terc-butilcalix[4]areno, com 12,7 % de extração. A inserção do metal foi qualitativamente avaliada através do deslocamento da banda do picrato.
26
McCartney, Clair Marie. "Electrical and structural properties of calixarene Langmuir-Blodgett films." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301606.
Full text
27
Lowe, Christian T. "Retention Characteristics of Water-Soluble Calixarene Modified Mobile Phases." Youngstown State University / OhioLINK, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=ysu997550028.
Full text
28
Russell, Julie Alexandrea. "Functionalised calixarenes as chiral chromatographic selectors." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361305.
Full text
29
Frank, Nicolas. "d10-Metallkomplexe des p-tert-Butyltetramercaptotetrathiacalix[4]arens." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21975.
Full textAbstract:
Ziel dieser Arbeit war es, das Potenzial von p-tert-Butyltetramercaptotetrathiacalix[4]aren (H4(MTC[4])) zum Aufbau von mehrkernigen Komplexen mit weichen Metallionen mit d10-Elektronenkonfiguration zu untersuchen. H4(MTC[4]) bietet im Vergleich zum bekannteren p-tert-Butylcalix[4]aren erweiterte Bindungsmöglichkeiten für Metallionen an den Thioetherbrücken. Die Funktion der Metallionen Cu(I) und Zn(II) in biologischen Systemen lieferte die anfängliche Inspiration, jedoch erschien auch die Untersuchung anderer Metalle wie Nickel, Silber und Gold in Verbindung mit (MTC[4])4- Liganden lohnenswert, da diese Metalle durch ihre jeweils bevorzugten Koordinationsgeometrien neue Strukturen und Koordinationsmöglichkeiten an H4(MTC[4]) aufzeigen könnten.
In Experimenten mit Kupfer(I)-Ionen konnten der Kupferkomplex [(Ph3PCu)4(MTC[4])] sowie das Hexamer [Cu4(MTC[4])]6 hergestellt und charakterisiert werden. [Cu4(MTC[4])]6 weist eine einzigartige, supramolekulare, hohle Cu24S48-Käfigstruktur auf. Die [Cu4(MTC[4])]-Einheiten werden durch Cu2S2-Motive verknüpft, die extrem kurze Cu···Cu-Abstände aufweisen. Durch NMR-Experimente wurde gezeigt, dass die Hohlräume von [Cu4(MTC[4])]6 in Lösung Acetonitril und Methan aufnehmen können.
In Experimenten mit Silber(I)-Ionen wurden die Molekülstrukturen der Silberkomplexe [(Ph3PAg)2AgH(MTC[4])], [(Ph3PAg)4AgCl(MTC[4])] und [(Ph3PAg)4(MTC[4])] bestimmt. Diese zeigen, dass H4(MTC[4]) gegenüber Silber- und Kupferionen ein ähnliches Koordinationsverhalten aufweist.
In Experimenten mit Gold(I)-vorläufern war es möglich, zu steuern, wie viele Metallionen ein einzelnes Molekül H4(MTC[4]) koordiniert. Die Komplexe [(Ph3PAu)2H2(MTC[4])], [(Me3PAu)3H(MTC[4])] und [(Me3PAu)4TlCl(MTC[4])] wurden synthetisiert. Diese bieten teilweise durch vorhandene freie Thiolfunktionen Potenzial für die Synthese heterometallischer Komplexe.It was the aim of this work, to assess the potential of p-tert-Butyltetramercaptotetrathiacalix[4]arene (H4(MTC[4])) to create multinuclear complexes with soft metal ions of d10 electron configuration. In contrast to the more known p-tert-Butylcalix[4]aren, H4(MTC[4]) offers extended possibilities for the coordination of metal ions at the thioether groups. While this work was initially inspired by the function of Cu(I) and Zn(II) ions in biological systems, the metal ions, which were incorporated into the Calixarene, were soon expanded by Ni(II), Ag(I) and Au(I) ions. Through their different preferred coordination geometries, these metal ions could yield new information about coordination modes of H4(MTC[4]). In experiments with copper(I) ions the complex [(Ph3PCu)4(MTC[4])] and the hexamer [Cu4(MTC[4])]6 were synthesized and characterized. [Cu4(MTC[4])]6 consists of a unique, supramolecular hollow Cu24S48 cage structure. The [Cu4(MTC[4])] units are connected by Cu2S2 motivs, which display extraordinary short Cu···Cu distances. An investigation by NMR spectroscopy indicated that the cavities of [Cu4(MTC[4])] in solution can hold acetonitrile or methane molecules. In experiments with silver(I) ions, the molecular structures of the compounds [(Ph3PAg)2AgH(MTC[4])], [(Ph3PAg)4AgCl(MTC[4])] and [(Ph3PAg)4(MTC[4])] were determined. In these compounds H4(MTC[4]) exhibits a similar coordination behaviour towards Ag(I) ions as it does towards Cu(I) ions. In experiments with gold(I) precursors it was possible to control how many gold(I) ions were coordinated by H4(MTC[4]). The complexes [(Ph3PAu)2H2(MTC[4])], [(Me3PAu)3H(MTC[4])] and [(Me3PAu)4TlCl(MTC[4])] were synthesized and studied. Due to their free thiol functions, they are potential precursors for the synthesis of heterometallic complexes.
30
Crowe, Lindsey Alexandra. "NMR of solid phosphorus-containing compounds." Thesis, Durham University, 1999. http://etheses.dur.ac.uk/4502/.
Full textAbstract:
Solid-state NMR techniques have been applied to the structure and dynamic characterisation of a range of phosphorus-containing compounds. Comparisons have been made within several series of compounds as well as studies of individual molecules with interesting NMR properties, whether dynamic, structural or magnetic. Spectral features such as shielding anisotropy, the high sensitivity of phosphorus and its large chemical shift range are extensively utilised in this work. Triple-channel, fluorine-observe and variable-temperature spectrometer facilities at different magnetic field strengths have been explored to give as much complementary information as possible. For both chlorinated and fluorinated diazadiphosphetidines, motional properties have been examined and the indirect spin-spin and dipolar interactions, together with shielding have been studied. Spectra from the NMR-active nuclei in these cyclic dimers have been used to compare effects of differing substituents on NMR properties. The bowl-shaped' molecules, calix[4] resorcinols with phosphorus functionality modifying the upper rim, constitute the other major group of compounds studied. These are of interest in inclusion chemistry. As well as simple one-dimensional NMR characterisation of solid-state calix[4]resorcinol compounds, interesting two-dimensional correlation results have helped with the assignment and conformational conclusions. A qualitative and quantitative study of a co-crystal of triphenylphosphine oxide and phenol was made to establish the nature of the disorder observed, but undefined, in an X-ray structural investigation of the hydrogen-bonded network. Complementary NMR techniques were used to extend the temperature range over which the rate of any motion can be characterised. Bandshape analysis, Tip measurement and selective polarisation inversion experiments have proved to be accurate in different regions of a variable temperature study. Other compounds explored were those which showed interesting solid-state NMR results, for example, the complexities of cross-polarisation dynamics between two abundant spins in inorganic phosphates, and compounds with potential solid-state applications. These include (i) phosphorus-containing compounds with chlorine and fluorinated aromatic substituents and (ii) complexes with transition metals. Comparison with single-crystal and powder X-ray diffraction has also been exploited. In some cases, data have been produced, and in others the applicability of a theoretical approach has led to other conclusions.
31
Browne, Julie K. "Synthesis and complexation properties of novel calixarenes." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287293.
Full text
32
Kowalska, Dorota. "Thermodynamic aspects of lower rim calix(4)arene ketone derivatives and their metal-ion complexes in solution and in the solid state." Thesis, University of Surrey, 2003. http://epubs.surrey.ac.uk/844564/.
Full textAbstract:
Following an introduction on calixarene chemistry and their metal-ion complexes including some of their applications, the aims of the work are described. Thus, this thesis concerns an investigation on the solution properties of p-tert-butylcalix(4)arene tetraketone derivatives and their metal-ion complexes. Macrocycles such as 5,11,17,23-tetra-terf-butyl-25,26,27,28-tetra(benzoyl)methoxycalix(4)arene and 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetra(acetoyl)methoxy calix(4) arene are structurally (1H NMR and X-ray crystallography) and thermodynamically (solubility, calorimetry) characterised. The complexing abilities of these ligands for metal cations are investigated by a variety of techniques. To obtain information about the active sites of the ligand in its interaction with metal cations, 1H NMR studies were performed. Conductance and UV spectrophotometric measurements were used to establish the composition of the metal-ion complexes in dipolar aprotic media. Potentiometric and calorimetric measurements were carried out to derive the thermodynamic parameters of complexation of p-tert-butylcalix(4)arene tetramethyl ketone and metal-ions in acetonitrile at 298.15 K. This ligand shows the highest affinity for calcium amongst all the investigated metal cations. The medium effect on the complexation process involving metal cations and calixarene derivatives is quantitatively assessed using as an illustrative example the interaction of p-terf-butylcalix(4)arene tetraphenyl ketone and the sodium cation. Thus, detailed thermodynamics of this system is reported taking into account the solution properties of the reactants and the product in various solvents and in acetonitrile / N,N- dimethylformamide solvent mixtures. In these mixtures a linear relationship is observed between the stability constant and the solvent composition. The strength of complexation decreases from MeCN through the mixtures to pure DMF. However in terms of the enthalpy of complexation, only small variations are found between the values in different mixtures. The complexation and solution data for the reactants and the product are used to calculate the standard co-ordination enthalpies as a means of checking the reliability of the data. Based on stability constant data, two metal-ion complexes were isolated. X-ray diffraction data shows that p-tert-butylcalix(4)arene tetraphenyl ketone hosts the sodium cation in its hydrophilic cavity where it is coordinated by four ethereal oxygen atoms and four carbonyl oxygen atoms. One molecule of acetonitrile is found in the hydrophobic cavity of the ligand with the CH3 end pointing inward. The crystal structure of the cadmium and acetonitrile p-tert-butylcalix(4)arene tetramethyl ketone complex shows that the metal ion is coordinated by four ethereal oxygen atoms of the ligand and only by three carbonyl oxygens. The eight coordination site is provided by the nitrogen atom of the molecule of acetonitrile which is present in the hydrophobic cavity of calixarene derivative with the CN end pointing inward. Conclusions and suggestions for further research in this area are given.
33
Clark, Thomas Edward. "Calixarene chemistry en route to nano-fabrication of phosphonated analogues." University of Western Australia. School of Biomedical, Biomolecular and Chemical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0052.
Full textAbstract:
[Truncated abstract] An efficient synthesis of the p-phosphonic acid calix[n]arenes, (n = 4, 5, 6 and 8) in five steps and excellent yield has been developed. This includes the key use of an acetyl protecting group, which is straightforward to introduce and remove using acetic anhydride and potassium hydroxide respectively. The synthesized p-phosphonic acid calixarenes are water-soluble and the hydrogen bonding prowess of the acidic groups dominates its selfassembly processes. For p-phosphonic acid calix[4]arene these include the formation of nano-rafts in the gas phase (≤ 20 molecules) and nano-particles (3.0(3) and 20.0(2) nm) of the calixarene in water using spinning disc processing stabilized by acetonitrile. The larger p-phosphonic acid calix[5,6,8]arenes also show nano-raft formation in both solution and the gas phase. An extensive study of the supramolecular chemistry of calix[5]arene has also been undertaken to better understand its rich structural diversity. This includes the formation of chloromethane inclusion complexes of p-tert-butyl-calix[5]arene and p-H-calix[5]arene with dichloromethane, p-phenyl-calix[5]arene with chloroform and their potential application as gas storage materials. Along with these three investigated inclusion complexes are two sublimates of p-H-calix[5]arene (α and β) with only the β-polymorph active for sorption of carbon dioxide at room temperature and 1 atm. The α-polymorph adopts an inverted cone conformation and forms helical stacks in the extended structure whereas the β-polymorph adopts the usual cone conformation and packs in both 'self included' and 'back-to-back' helical arrangements. ... Complementary to this study involved the p-H-calix[5]arene inclusion complexes with fluoro-, chloro-, bromo- and iodobenzene. All but the iodobenzene complexes are isostructural forming columnar arrays in the extended packing comprised of 'tri-calix[5]arene' segments. Iodobenzene is too large to form the respective 'tri-calix[5]arene' segments and instead forms sheets in the extended packing. To better understand the type and nature of the intermolecular interactions present within the supermolecules and extended structures a detailed Hirshfeld surface analysis was performed. A detailed Hirshfeld surface analysis was also performed on O-octadecyl-calix[6]arene, which crystallizes in the inverted double cone conformation. Three alkyl chains on either side interplay to form one side of hexagon in an hexagonal close packed array of interdigitated alkyl chains. This was the first Hirshfeld surface analysis performed at variable temperatures and enhanced the description of such a large supramolecular system. The related compound O-octadecyl-calix[4]arene was found to crystallize from toluene or benzene as supramolecular bilayers, 32.2(4) and 32.7(2) Å thick respectively. The calixarenes adopt the cone conformation and the alkyl chains interplay to form a continuous hexagonal motif similar to that seen for O-octadecyl-calix[6]arene. The formation of stable bilayers using octadecyl chains leads to the possibility of inserting long chain calixarenes with suitable functionalization into biological membranes. Such functionalization could include upper rim phosphorylation as seen for the p-phosphonic acid calixarenes to produce phospholipid mimics.
34
Supian, Faridah Lisa. "Sensing interactions within nanoscale calixarene and polysiloxane Langmuir-Blodgett films." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538002.
Full text
35
Barrett, Geraldine Patricia. "Synthesis and physico-chemical properties of chemically modified calixarene receptors." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333798.
Full text
36
Walker, Andrew W. "Synthesis and X-ray structure analysis of novel calixarene receptors." Thesis, Queen's University Belfast, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318740.
Full text
37
Pailleret, Alain. "Electrochemistry of calixarene derivatives : applications in electroanalysis and surface functionalisation." Thesis, University of Salford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272699.
Full text
38
Holloway, Alan Franciszek. "Advanced quartz crystal microbalance techniques applied to calixarene sensing membranes." Thesis, Sheffield Hallam University, 2005. http://shura.shu.ac.uk/19817/.
Full textAbstract:
Several Quartz Crystal Microbalance (QCM) measurement techniques in conjunction with a series of calix[4]resorcinarene sensing membranes have been successfully exploited for the detection of volatile organic solvents at vapour concentrations below their lower explosive level. The impedance analysis technique involves the measurement of the electrical properties of the QCM around the resonant frequencies of crystal. Subsequent fitting of the measured spectra to an equivalent circuit allows parameters directly related to mass loading and the mechanical properties (viscosity) of the film to be obtained. An experimental setup which allows the real time in situ extraction of these parameters has been developed. It has been shown that unique changes in mass loading and the films viscoelastic properties caused by the adsorption of target vapours into a calix[4]resorcinarene C15H31 sensing membrane can be detected. In some cases this facilitates both the detection and discrimination of target vapours using a single QCM sensing element. The changes in the films mechanical properties are believed to be caused by capillary condensation of vapours at values below saturated vapour pressure inside the nano-porous calix[4]resorcinarene film matrix. The work is extended by the use of the sensor array technique. In the first instance frequency only measurements are used. Four QCM have been coated with calix[4]resorcinarene compounds with different hydrocarbon chain lengths and exposed to range of organic vapours. The variation in chain length produces selectivity between the sensing membranes, and leads to the classification of all the tested organic vapours using a feed forward multilayer Artificial Neural Network. The trained network successfully classified over 98% of the test data. The additional measurement of film dissipation using impedance analysis/QCMD shows interesting phenomena. An unexpected increase in mechanical stiffness of the film is observed for small chain length C[4]RA compounds (CH3) on vapour sorption. A speculative model has been proposed relating the chain length and effective cavity size to the observed phenomena. An alternative low cost multi parameter measurement set up has also been developed using the QCMD principle. The crystal is driven from an external oscillatory source and subsequently disconnected. The resonant frequency and dissipation factor can be extracted from the decaying sinusoid signal. This approach eliminates the need for expensive network analysers. An additional multiplexing circuit has been combined with the QCMD technique and allows both the frequency and dissipation factor of several crystals to be measured in pseudo real time. This makes the system ideally suited for multi parameter array measurements. The basis for a discriminative explosive vapour sensor based on calix[4]resorcinarene membranes has been investigated and promising results for future development have been obtained. The exact adsorption mechanisms are however complex and althoughspeculative models have been proposed, further research is suggested to fully characterize the complete adsorption process and the mechanical changes taking place within the film.
39
Clark, Thomas Edward. "Calixarene chemistry en route to nano-fabrication of phosphonated analogues /." Connect to this title, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0052.
Full text
40
Wehbie, Moheddine. "Systèmes chélatants organisés pour l'extraction sélective de métaux stratégiques." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT247.
Full textAbstract:
L’extraction liquide-liquide fait partie des procédés hydrométallurgiques les plus étudiés et développés, particulièrement dans les domaines d'applications de l’extraction et de la purification de métaux comme les lanthanides et les actinides, de grand intérêt dans les secteurs de l'énergie et des technologies de pointe. De nombreux extractants ont ainsi été développés au cours des dernières décennies dont la nature et l’arrangement des sites de chélation, la rigidité voire la stéréochimie déterminent l’affinité et la sélectivité vis-à-vis d’une cible métallique. L’étude de systèmes chélatant organisés sur des macrocycles a notamment fait l’objet de nombreux travaux recherches. Dans cette étude, l'organisation de sous-unités diglycolamide (DGA) et diamide (DA) sur des plateformes macrocycliques tel que le calix[4]arène et le résorcinarène a été abordée vis-à-vis de l’extraction des terres rares et de l’uranium. Une étude détaillée de l'effet de l'organisation du DGA sur les performances d'extraction montre que les macrocycles synthétisés sont plus affins et sélectifs des terres rares lourdes (HREEs) que des légères (LREEs). Une étude comparative dédiée à l'extraction des lanthanides par ces macrocycles en milieu liquide ionique montre également que le calix[4]arène est un meilleur candidat comme plateforme pré-organisatrice que le cavitand résorcinarène. D'autre part, une étude détaillée sur le pouvoir chélatant d’un calixarène fonctionnalisé par des diamides a été entreprise pour l'extraction sélective de l'uranium en milieu sulfurique, démontrant ici que le motif diamide est plus efficace et plus sélectif que l’analogue calixaréniqueThe liquid-liquid extraction is one of the most studied and developed hydrometallurgical processes, particularly in the areas of applications for the extraction and purification of metals of great interest in the sectors of energy and advanced technologies, such as lanthanides and actinides. Many extractants have been developed for the extraction of these metals in the recent decades where the nature, the arrangement, the rigidity and the stereochemistry of chelating sites determine the affinity and selectivity toward the target metals. The study of chelating systems organized on macrocycles has constituted, in particular, the subject of numerous research studies.In this study, the organization of diglycolamide (DGA) and diamide (DA) subunits on Calix-[4]-arene and resorcinarene cavitand was studied for the extraction of rare earth elements (REEs) and uranium (U). A detailed study on the effect of the organization of DGA subunit on the extraction performance of lanthanides, in toluene, showed that the synthesized macrocycles are more efficient and more selective toward heavy rare earths (HREEs) than the light ones (LREEs). A comparative study for the extraction of lanthanides by these macrocycles in ionic liquid medium revealed that the calix-[4]-arene is a better candidate as preorganised platform than the resorcinarene cavitand. Moreover, a detailed study on the chelating capacity of a calixarene functionalized with diamides (DA) was done for the selective extraction of uranium in sulfuric medium, demonstrating that the diamide pattern is more efficient and more selective than its calixarene analogue
41
Madigan, Evelyn. "Synthesis of novel calixarenes for molecular recognition." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238988.
Full text
42
SOULEY, BAHARI. "Synthese et proprietes complexantes de calixarenes fonctionnalises." Université Louis Pasteur (Strasbourg) (1971-2008), 1997. http://www.theses.fr/1997STR13218.
Full textAbstract:
La premiere partie de ce travail concerne la synthese et l'etude conformationnelle des p-benzyl- et p-tert-octyl-calix5arenes (1 et 4) et de leurs derives penta-or (r = me, et, pr, bu, ch#2co#2r' (r' = me et et)) ainsi que l'etude des proprietes complexantes et extractantes des trois derives 1-ch#2co#2me, 1-ch#2co#2et et 4-ch#2co#2me. Les resultats de #1h rmn ont montre que ces derives sont bloques conformationnellement d'une facon sterique a partir de r = butyle. Les penta-esters montrent une preference pour les cations alcalins volumineux (k#+, rb#+ et cs#+) par rapport a li#+ et na#+, preference modulee par le substituant en para du calixarene, le residu alkoxy de l'ester et le solvant. La seconde partie decrit les interactions entre quatre calix4arenes-bis-ethers-couronnes (bc5, bc6, bc6b et bc6n) bloques en conformation 1,3 alternee, et les cations alcalins. Les pourcentages d'extraction des picrates alcalins de l'eau au dichloromethane et les parametres thermodynamiques de complexation (g#c, h#c et ts#c) dans le methanol et l'acetonitrile ont ete determines. L'aptitude de ces ligands a separer les paires d'ions intimes formees par les picrates alcalins dans le tetrahydrofurane a egalement ete etudiee. Les resultats montrent que les complexes formes sont de stoechiometrie 1 : 1 et que les cations sont bien encages dans la cavite du calixarene. Ils mettent en evidence la remarquable selectivite cs#+/na#+ des derives couronnes-6 dont l'origine est expliquee. Contrairement aux resultats thermodynamiques, les etudes de #1h rmn ont mis en evidence dans certaines conditions la formation de complexes dinucleaires avec le bc5 et les cations li#+, na#+, k#+ et rb#+. La formation exclusive d'un complexe mononucleaire avec cs#+ a ete confirmee et des phenomenes d'echange inter- et intramoleculaires ont ete mis en evidence dans ce cas.
43
Ray, Priyanka. "Calixarenes and Nanoparticles : Synthesis, Properties and Applications." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112131.
Full textAbstract:
Le travail présenté dans ce manuscrit inclut la synthèse organique des différents types de calixarènes, l'étude de leurs propriétés optiques, des simulations théoriques pour déterminer leurs conformations favorables et leurs utilisations pour stabiliser des nanoparticules. Des nanoparticules d’argent, d’or, de platine et des nanoparticules bimétalliques (Ag-Au) ont été synthétisées en utilisant par réduction radiolytique ainsi que la synthèse la photochimique. Ces nanoparticules sont stabilisées en utilisant des calixarènes et divers polymères. Les nanomatériaux ont été caractérisés par spectroscopie d’absorption UV-Visible et spectroscopie de fluorescence et par des observations en microscopie électronique en transmission. Comme les nanoparticules métalliques sont connues pour leurs applications dans divers domaines, des propriétés antibactériennes de nanoparticules d'argent et des propriétés électrocatalytiques des nanoparticules d'or ont été testéesThe work presented in this manuscript includes the organic synthesis of different types of calixarenes, the study of their optical properties, computational studies for determination of their favourable conformations and their use in the stabilisation of nanoparticles. Silver, gold, platinum and bimetallic (Ag-Au) nanoparticles were synthesised using radiolytic reduction as well as photochemical method. These nanoparticles were stabilised by calixarenes and also other ligands which included several polymers. The nanomaterials were characterised using UV-Visible absorption and fluorescence spectroscopy and transmission electron microscopy (TEM) measurements. As metal nanoparticles are known for their applications in various fields, the antibacterial properties of silver nanoparticles and the electrocatalytic properties of gold nanoparticles were tested
44
Jones, Liza T. "Nitrogen dioxide sensing using porphyrin and porphyrin-calixarene hybrid LB films." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397502.
Full text
45
Lowe, Christian T. "Retention characteristics of water-soluable calixarene modified mobile phases in HPLC /." Connect to the full text of the document, 1998. http://www.ohiolink.edu/etd/view.cgi?ysu997550028.
Full text
46
Phe, Rene Zhi Hui. "Solution phase and solid state studies of lanthanoid-calixarene bottlebrush clusters." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/68324.
Full textAbstract:
The conditions required for formation of unusual bottlebrush-shaped lanthanoid coordination clusters were investigated. The known clusters are supported by tetrazole-functionalised p-t-butylcalixarenes, and carboxylate co-ligands. It was confirmed that the lighter lanthanoids form mononuclear complexes, and heavier lanthanoids form bottlebrush clusters. Changing the carboxylate co-ligand had little impact on the complexes formed. Altering the structure of the calixarene had a significant impact. When the t-butyl group was replaced with hydrogen or allyl groups, mononuclear complexes formed.
47
Hefley, Ronnie. "Chiral Calixarenes as Potential Enantiospecific Stationary Phases in Capillary Gas Chromatography." Youngstown State University / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1002049443.
Full text
48
Gebauer, Sabine. "Calixaren-Kieselgele unterschiedlich grosse Makrocyclen als chromatographische Selektoren in der HPLC /." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=960868992.
Full text
49
Chester, Ryan Travis. "Calixarenes as potential lonophores for Thallium lonselective electrodes." Curtin University of Technology, Department of Applied Chemistry, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17316.
Full textAbstract:
The first part of this thesis reports the synthesis of five calixarene molecules and their incorporation into ISEs as thallium(I) selective ionophores for use in clinical and environmental analysis. Four calix[4]arene molecules were successfully synthesized. Two were isolated in the cone conformation with iso-propyl groups attached to the lower rim. The other two were in the 1,3-alternate conformation with allyl groups attached to the phenolic oxygen. The final calixarene synthesized was a calix[6]arene that was partially substituted with iso-propyl groups on the lower rim. The parallel orientation of the aromatic rings was confirmed using single crystal X-ray structure determination. Nuclear Magnetic Resonance (NMR) complexation studies were conducted on the four calix[4]arene derivatives and showed that thallium binds within the aromatic cavity, and that the complexation/decomplexation kinetics and molecule flexibility are affected by the incorporated ion and the attached groups on the calixarene. Once the binding characteristics of the synthesized calixarenes had been examined they were then incorporated into plasticized PVC together with an ion-exchanger to make ISEs capable of determining thallium activities in solutions. Three calixarenes were successfully incorporated into the membranes and produced Nernstian responses over the concentration range 10-2-10-6 M TlNO3. The lower detection limit of the above electrodes lies in the micro-molar range, which is a common characteristic of the experimental setup used. Since the electrodes behaved ideally with respect to thallium(I), it was then decided to test the complex formation constants and selectivities of the three ionophores.The complex formation constant (Log βILn) of two of the calixarene derivatives with thallium(I) were determined to be 6.44 and 5.85 respectively, through the use of the sandwich membrane technique. The selectivities were measured with a new protocol, whereby the electrode had not previously come into contact with the primary ion. This helps to remove ion fluxes of the primary ion and subsequent biased selectivity coefficient of highly discriminated ions. The three ionophores showed excellent selectivity against Zn2+, Ca2+, Ba2+, Cu2+, Cd2+ and Al3+, and moderate selectivity against Pb2+, Li+, Na+, H+, K+, NH4+ and Cs+. Silver was the only common high interferent in all three ionophores tested. As the detection limits of current thallium(I) ISEs in the literature would be insufficient in practical samples, attempts were made to lower the detection limits of the above ISEs with the application of relatively new experimental techniques. The lower detection limit of the three ISEs was successfully lowered by an order of magnitude from the original values through the use of an EDTA-buffered inner filling solution. The lowest achieved detection limit was obtained with the iso-propyl functionalized calix[4]arene, which reached a value of 8.32 nM (IUPAC definition).
The second part of the thesis investigated the incorporation of one of the calixarenes into a solid-contact ISE (SC-ISEs), which are seen as the future in this field due to their potential for miniaturisation and use in lab-on-a-chip applications. Four different solid-contact designs were tested to evaluate which was the best to pursue for future testing. The chosen calixarene was successfully incorporated into all four designs with Nernstian responses recorded in each case. The best response was recorded for an electrode which had a solid gold substrate, poly(3-octylthiophene) (POT) intermediate layer and a methyl methacrylate/decyl methacrylate (MMA-DMA) co-polymer membrane. This electrode exhibited a slope of 58.4 mV decade-1 and a lower detection limit of 30.2 nM. The other three solid-contact electrodes, which consisted of a graphite contact, a plasticised PVC membrane on a gold substrate, and a plasticized PVC membrane on a gold substrate with a polypyrrole intermediate layer, exhibited detection limits that were inferior to the MMA-DMA/POT SC-ISE. Further tests were used to assess one of the main problems associated with SC-ISEs, being the presence of water layers of droplets between the membrane and the solid substrate. Potential tests, electrochemical impedance spectroscopy, small angle neutron scattering and the electrode’s reactivity to changes in the concentration of dissolved oxygen were used to study water uptake and the concomitant formation of water layers in solid-contact ISEs. Water was confirmed at the surface of the membrane that consisted only of the membrane and gold substrate, but was not confirmed for the other three electrode designs.
50
Loiseau, Francois Alexandre. "Synthesis of pegylated calixarenes towards new tuberculosis therapies." Thesis, King's College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407603.
Full text