To see the other types of publications on this topic, follow the link: Macrocycles.
Dissertations / Theses on the topic 'Macrocycles'
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 'Macrocycles.'
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
Azarias, Cloé. "Modeling azacalixphyrin macrocycles." Thesis, Nantes, 2018. http://www.theses.fr/2018NANT4021/document.
Full textAbstract:
Cette thèse porte sur la modélisation des propriétés structurales, aromatiques et spectroscopiques d'une nouvelle classe de macrocycles alternatifs aux porphyrines, les azacalixphyrines (ACPs). Ces macrocycles conjugués, synthétisés et caractérisés pour la première fois en 2010 par le groupe d’Olivier Siri à Marseille, ont montré des propriétés exceptionnelles (structure, absorption, tautomérie, et complexation). Cette thèse vise à proposer de nouveaux dérivés aux propriétés améliorées, notamment en ce qui concerne leur absorption, en utilisant les outils offerts par la chimie théorique. Parmi toutes les approches ab initio permettant de modéliser les ACPs, la théorie fonctionnelle de la densité (DFT) et sa forme dépendante du temps (TDDFT) ont été principalement appliquées, bien que des calculs utilisant des méthodes alternatives aient également été effectués, notamment à l'aide du formalisme Bethe-Salpeter (BSE/evGW) dans le cadre d'une collaboration avec l'équipe du Dr. Xavier Blase à Grenoble. Trois stratégies chimiques ont été évaluées: (i) l’extension de la délocalisation des électrons en fusionnant plusieurs unités ACP; (ii) la substitution de l’ACP via l'addition de groupes électroactifs; et (iii) le couplage du macrocycle avec un fluorophore présentant une absorption complémentaire afin d'absorber la lumière sur une plus grande gamme du spectre et déclencher des processus de transfert d'énergie entre les sous-unités. Les deux premiers axes ont été réalisés en collaboration avec l'équipe d’Olivier Siri alors que le dernier est le fruit d'une collaboration avec le groupe de Benedetta Mennucci à PiseThis thesis focuses on the modeling of the structural, aromatic, and spectroscopic properties of a new class of macrocycles alternative to porphyrins, i.e., azacalixphyrins (ACPs). These conjugated macrocycles have first been synthesized and characterized in 2010 by Siri’s group in Marseille and revealed exceptional features (structure, NIR absorption, tautomerism, and complexation). This thesis aimed at using ab initio methods to propose new ACP derivatives with improved properties with a focus on their absorption. The Density Functional Theory (DFT) and Time- Dependent DFT (TD-DFT) methods have been predominantly applied, although alternative wavefunction-based theories [the second-order Coupled-Cluster, CC2, and the Algebraic Diagrammatic Construction, ADC(2)] as well as the Bethe-Salpeter formalism, BSE/evGW, have also been used. Three major directions to develop new ACP derivatives have been investigated: (i) the extension of the ACP -conjugation path by fusing several ACP moieties leading to multimers; (ii) chemical modifications of the ACP unit by addition of electroactive groups; and (iii) coupling of the ACP moiety with a fluorophore presenting a complementary absorption spectrum in order to improve the light harvesting and to trigger excitation energy transfer processes. The two former axes have been investigated in collaboration with Siri’s team whereas the latter has arisen from a collaboration with the Mennucci’s group
2
Danso-Danquah, Richmond Edward. "Syntheses of polypyrrolic macrocycles." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26240.
Full textAbstract:
Pentaphyrins are pentapyrrolic macrocycles containing five bridging methine groups between the five pyrrolic subunits. The syntheses of decamethylpentaphyrin 71, 2-ethoxycarbonyl-3,7,8,12,13,17,18,22,23-nonamethylpentaphyrin 74, 2-ethoxycarbonyl-3,7,8,22,23-pentamethyl-12,13,17,18-tetraethylpentaphyrin 75, 3,12-dimethoxycarbonylethyl-2,7,8,-13,17,18,22,23-octamethylpentaphyrins 29 and the zinc complexes of 71 and 74 are described.
The physical properties of the pentaphyrins show them to be aromatic like sapphyrins, porphyrins and corroles. This aromaticity is reflected in the large shielding of the NH protons and the deshielding of the methine protons in the nmr spectra and by their optical spectra, which exhibit Soret and visible bands similar to sapphyrins and porphyrins.Science, Faculty of
Chemistry, Department of
Graduate
3
Norman, Timothy John. "Radioimmunotherapy with yttrium macrocycles." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5529/.
Full textAbstract:
Monoclonal antibody fragments (Fab') which recognise tumour-associated antigens provide an ingenious means of selectively targeting a therapeutic radionuclide to a tumour for radioimmunotherapy. The radionuclide yttrium-90, a long range β(^-) emitter, was chosen to deliver a sterilising dose of radiation to the tumour. A selection of novel functionalised macrocyclic ligands based on a 1,4,7,10-tetraazacyclododecane skeleton have been synthesised, and the stabilities of their yttrium (III) and gadolinium (III) complexes studied in vitro through association and dissociation measurements, and in vivo through animal biodistribution studies. The radiolabelled complexes do not dissociate in vivo. Maleimides are compounds which are capable of selectively reacting with a thiol of an antibody fragment. Selective functionalisation of one of the yttrium binding macrocyclic ligands with either one or three maleimides has been carried out, and the resulting compounds conjugated to tumour seeking humanised antibody fragments. Subsequent radiolabelling with (^90)Y, gave the desired tumour targeting drug for use in radioimmunotherapy. Acridines are a class of intercalating agents which are capable of reversibly binding to DNA. A maleimide functionalised ligand derivatised with acridine was formed. Conjugation of this compound to antibody fragments capable of entering a tumour cell, may permit drug binding to tumour cell DNA, and thus enhance the targeting efficacy of the radiolabelled conjugate.
4
Matthes, Karen Elizabeth. "Chemistry of functionalised macrocycles." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/6704/.
Full textAbstract:
The work reported in this thesis is divided into two distinct areas. The first involves the synthesis of monoaza- and diaza-[12]-ring macrocycles, with differing side-arm N-substituents. The twelve-membered macrocycles possess a convenient ring-size for exploring the stability and selectivity of complexation of small cations, in particular those from groups IA and IIA. Amide substituents on nitrogen were expected to function as effective σ-donors to cations with high charge density (e.g. Li (^+), Ca (^2)(^+)), because of their high ground state dipole moments. The effect of the length of the side-arms attached to nitrogen on the complexation has also been studied. Complexation behaviour has been probed using (^13)C NMR spectroscopy, titration calorimetry, and fast-atom bombardment mass spectroscopy. Copper (II) complexes of three of the [12]-ring cycles have also been characterised by X-ray crystallographic analysis. The second area involves the study of a series of macrocyclic ligands capable of forming homo- and hetero-dinuclear complexes. In particular, ligands containing the pyridyl-dithio (PyS(_2)) binding unit and a polyether chain linking the two sulphur atoms have been examined. The three binding atoms of each PyS (_2) group define three corners of a fairly rigid square planar environment which favours the formation of square planar d(^8) complexes. Accordingly, complexation with rhodium (I) [and (III)], palladium (II), and platinum (II) has been investigated: the structural properties of these complexes have been determined by the use of FT NMR and X-ray crystallography.
5
Sloman, Zachary Scott. "Novel thiophene based macrocycles." Thesis, Nottingham Trent University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297724.
Full text
6
Marrs, Deborah Jane. "Macrocycles, macrobicycles : a study." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257447.
Full text
7
Colombo-Khater, Dominique. "Macrocycles polyhétéroatomiques : synthèse, complexation." Toulouse 3, 1993. http://www.theses.fr/1993TOU30001.
Full textAbstract:
Depuis quelques annees, de nombreux macrocycles phosphores contenant des heteroatomes ont ete prepares dans le but d'obtenir des especes capables de complexer selectivement des cations voire meme des especes neutres. La methode de synthese mise au point au laboratoire en 1988 consiste a faire reagir un dialdehyde sur un phosphodihydrazide. Il s'agit d'une methode simple et generale de synthese de macrocycles polyphosphores. La reaction mise en jeu est une reaction de cyclocondensation 2+2. L'etude bibliographique presentee dans le premier chapitre nous a permis de faire le point sur les differentes methodes de synthese de macrocycles polyheteroatomiques phosphores, silicies et bores. Dans le second chapitre de cette these, nous decrivons la preparation de nouveaux precurseurs phosphores de macrocycles. Le troisieme chapitre decrit la mise au point de deux voies de synthese permettant l'acces aux premiers macrocycles tetraphosphores fonctionnalises ou non, contenant des atomes de phosphore intracycliques a environnement n-p-n et o-p-o. La synthese de macrocycles phosphores possedant des heteroelements des groupes 13 et 14 tels que le silicium et le bore dans la chaine macrocyclique est egalement decrite dans ce chapitre. Enfin quelques aspects de la reactivite et des proprietes de complexation des precurseurs phosphores synthetises dans le second chapitre de ce memoire seront abordes dans cette quatrieme partie. Des complexes macrocycliques ou non du nickel, zirconium, titane et baryum seront decrits. Des monocristaux ont pu etre isoles dans le cas de certains complexes du nickel. L'etude des structures par diffraction de rx sera developpee
8
Watson, Walter Philip. "Hybrid Macrocycles for Supramolecular Assemblies." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6958.
Full textAbstract:
Hybrid macrocycles, which chimerically integrate multiple chemical compositions and architectures, provide an effective way to impart new properties to polymers that are not found in their linear or homocyclic analogues. This dissertation addresses the incorporation of hydrophilic blocks into hydrophobic polymer, as either a poly(dimethyl siloxane)-block-poly(oxyethylene) (PDMS-POE) tadpole with a hydrophobic head and a hydrophilic tail or as a diblock poly(styrene)-block-diethylene glycol (PS-DEG) hydrophobic-hydrophilic macrocycle. The supramolecular association properties of both kinds of cycles were studied: the PDMS-POE tadpoles in forming micelles, and the PS-DEG macrocycles in threading with linear polymer to form polyrotaxanes.
For the PDMS-POE macrocycle, linear alpha,omega-dihydroxy PDMS was cyclized under dilute conditions with dichloromethylhydrosilane as a linking group to produce hydrosilane-functionalized cyclic PDMS. This was joined to alpha-methoxy,omega-allyl POE via a free radical hydrosilylation reaction to produce the hybrid tadpole macrocycle, which was analyzed by GPC, DSC, and 1H, 13C, and 29Si NMR spectroscopy. Supramolecular aggregation consisting of the formation of micelles under both polar and nonpolar conditions was studied by surface tensiometry and quasielastic light scattering. For the PS-DEG macrocycle, linear alpha,omega-dihydroxy PS was prepared by ATRP polymerization of styrene, followed by reaction with KOH to give hydroxyl endgroups. The linear PS was then cyclized under dilute conditions with diethylene glycol ditosylate, and the product was analyzed by GPC, MALDI-TOF MS, DSC, and 1H, 13C and DOSY NMR spectroscopy. The macrocycle was then statistically threaded with linear PS to give the supramolecular structure poly(styrene)-rotaxa-cyclo[poly(styrene)-block-diethylene glycol]. Characterization was performed with DOSY NMR to verify that the product was threaded, and 1H NMR was collected to determine that the product was 13% macrocycle by weight. DSC showed only one Tg, indicating that the linear and cyclic species were present in the same phase.
9
Morphy, John Richard. "Functionalised macrocycles for tumour targeting." Thesis, Durham University, 1988. http://etheses.dur.ac.uk/6407/.
Full textAbstract:
Monoclonal antibodies which recognise tumour-associated antigens provide a means of targeting radionuclides selectively to tumour cells. (^99m)Tc and (^64)Cu are potentially useful isotopes for radioimmunoimaging;(^ 90)Y and (^67)Cu may be suitable for radioimmunotherapy. The synthesis of functionalised macrocycles for binding these four radioisotopes to antibodies is described. In each case, a macrocycle has been selected to provide a complex which is kinetically inert, thereby preventing dissociation of the radiolabel in vivo. A novel strategy for conjugating a C-alkylated cyclam derivative (for binding Tc and Cu) to an antibody is described. This method facilitates the selective acylation of an exocyclic primary amino group in the presence of the secondary ring nitrogens. Unfortunately, the labelling of antibody-bound cyclam with (^99m)Tc required conditions (pH 11) which produced extensive binding of the radiolabel to the protein backbone. "Non-specific" (^99m) Tc was subsequently found to dissociate in vivo. Pre-labelling the macrocycle with (^99m)Tc solved the "non-specifics" problem but required a pH which meant that the conjugation step was too slow for sufficient specific activity to be bound. A phenol-pendent derivative of cyclam was found to incorporate (^99m)Tc at a lower pH than cyclam itself. The "non-specific" binding of copper to the protein was minimised using a low pH labelling strategy in conjunction with a chelate wash. Macrocycle antibody conjugates labelled manner provide very promising biodistribution profiles in normal mice. A labelling buffer was selected to enhance the rate of uptake of copper by the macrocycle at low pH. Macrocycle-antibody conjugates containing 13N(_4), which was found to provide faster association kinetics than cyclam, have been prepared and await radiolabelling studies. A derivative of I3N(_4), containing 4 carboxylic acid donor sites, has been functionalised for conjugation to an antibody to act as a (^90)Y binder.
10
Wood, Ian. "Hydrogen bonded double helical macrocycles." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285635.
Full text
11
Munoz, Noelia Calcerrada. "Novel macrocycles derived from nucleosides." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343592.
Full text
12
Mainolfi, Nello. "Making cycles, bicycles and macrocycles." Thesis, King's College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415446.
Full text
13
Wright, Paul Trevor. "Synthesis of triphenylene based macrocycles." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242705.
Full text
14
Kowenicki, Richard Anthony. "Phosph(III)azane-based macrocycles." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615103.
Full text
15
Barreira-Fontecha, Julia. "Polynuclear complexes of pseudocalixarene macrocycles." Thesis, Loughborough University, 2006. https://dspace.lboro.ac.uk/2134/33927.
Full textAbstract:
As part of a program to synthesise and investigate macrocyclic polynuclear arrays, a new range of phenol based pseudocalixarene macrocycles have been synthesized, combining some of the properties of the Schiff-base and calixarene macrocycle systems. A series of dinuclear complexes of the pseudocalixarene macrocycle H6LI containing two 2,2'-methylenediphenol groups have been synthesised and structurally characterised.
16
Oussaid, Boualem. "Thiophène, pyrrole : synthèse, conformation, macrocycles." Toulouse 3, 1992. http://www.theses.fr/1992TOU30198.
Full textAbstract:
De nouveaux composes, derives du thiophene ou du pyrrole ont ete synthetises en plusieurs etapes. La conformation de divers composes thiopheniques ou pyrroliques a ete etablie a partir de calculs theoriques, de mesures de moments dipolaires et a partir du couplage stereospecifique a travers cinq liaisons. Quelques macrocycles possedant deux, trois ou quatre restes thiophene ou pyrrole a 18, 20, 30, 34 ou 40 chainons ont ete obtenus par des cyclisations de type 2+2, 3+3 ou 4+4
17
Badri, Meryam. "Macrocycles phosphorés : synthèse, structure, réactivité." Toulouse, INPT, 1990. http://www.theses.fr/1990INPT002G.
Full textAbstract:
Ce travail a ete consacre a la mise au point d'une strategie de synthese simple et efficace permettant l'acces a une nouvelle classe de macrocycles organophosphores. La reaction mise en jeu est une cyclocondensation entre dialdehydes et phosphodihydrazides. Apres une mise au point bibliographique sur les methodes de synthese des macrocyles phosphores, la preparation et la caracterisation des precurseurs acycliques (phosphodihydrazides, phosphodi, trihydradrazones fonctionnalisees, dialdehydes en 1-2, 1-3, 1-4, 1-11, trialdehydes 1-11-11) sont decrites. Dans une seconde partie, la synthese de macrocycles polyazadiphosphores tetraimines, fonctionnalises ou non a 18, 20, 22 et 26 chainons est reportee. Toutes ces molecules ont fait l'objet d'etudes structurales par rmn #1#3c, #1h, #3#1p en phase liquide, et en phase solide par diffraction des rayons x, spectroscopie infrarouge, et spectroscopie de masse. L'etude de la reactivite (reduction, silylation, alkylation. . . ) de la stabilite et des proprietes complexantes de ces macrocycles est traitee dans la derniere partie de ce memoire
18
Najimi, Ouafa. "Macrocycles tétrahétérocycliques synthèse et complexation /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376169502.
Full text
19
Boden, Britta Nicole. "Investigations of highly conjugated macrocycles and polymers for aggregation and chemical sensing." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/269.
Full textAbstract:
With the goal of developing Schiff base macrocycles with conjugation extended over multiple aromatic rings, new phenanthrene and triphenylene-containing bis(salicylates) were synthesized. A convenient route to 3,6,9,10-tetraalkoxy-2,7-diiodophenanthrene was developed. This compound has been found to be a useful precursor for Pd-catalyzed cross-coupling reactions.
Macrocycles were synthesized by Schiff base condensation of the phenanthrene and triphenylene precursors. Reaction of smaller phenanthrene and triphenylene bis(salicylates) with 1,2-dialkoxy-4,5-phenylenediamine afforded macrocycles in poor yield and purity, but formation of the macrocycle was confirmed by mass spectrometry. Condensation of larger phenanthrene ethynylene bis(salicylates) with phenylenediamines formed [3+3] Schiff base macrocycles in good yield and could be purified through recrystallization. These two large macrocycles were weakly luminescent, and showed decrease in intensity of emission in solution over time. Addition of nitroaromatic compounds to solutions of the macrocycles caused quenching of luminescence, but Stern-Volmer constants could not be determined. One of the macrocycles aggregates in solution and shows some order in the solid state. Association constants for self-assembly of this macrocycle in chloroform were determined, and aggregation was found to be enthalpically driven and entropically disfavoured. Both large macrocycles can complex metals, but low solubility prevents thorough characterization of the metal complexes.
Phenanthrene-containing poly(phenyleneethynylene)s (PPEs) and poly(phenylenevinylene)s (PPVs) were synthesized via the Sonogashira and Heckcouplings, respectively. The PPEs had high molecular weight and both polymers were extremely luminescent with OF = 70% for the PPE and OF = 59% for the PPV. These polymers show potential for use in solar cells and nitroaromatic sensors
.
Dithienylsalphen monomers were made using 4-(2-thienyl)salicylaldehyde and 5-(2-thienyl)salicylaldehyde. These monomers were coordinated to Ni(II), Cu(II) and vanadyl, and tested for electropolymerization. Conjugated dithienylsalphen monomers polymerize poorly, while non-conjugated dithienylsalphen monomers form good films through electropolymerization. Ultraviolet-visible spectroscopy confirmed extended conjugation in N,N '-phenylenebis(4-(2-thienyl)salicylideneimine).
20
Müri, Marcel [Verfasser]. "Shape Switchable Azo Macrocycles / Marcel Müri." München : Verlag Dr. Hut, 2011. http://d-nb.info/1015606938/34.
Full text
21
Everitt, Simon Robert Lorrie. "Peptidic macrocycles for enantioselective electrophile transfer." Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/683.
Full text
22
Tallis, Huw Aubrey. "Novel approaches towards phosphorous containing macrocycles." Thesis, Cardiff University, 2009. http://orca.cf.ac.uk/54905/.
Full textAbstract:
The first chapter in this thesis discusses the general trends in group 15 donor ligands, in particularly nitrogen and phosphorus. The major advancements in phosphorus donor macrocyclic chemistry over the past two decades are documented, and the various synthetic strategies are described. The properties of triphosphorus macrocycles and ensuing complexes are discussed, and the aims of this thesis are summarised. In chapter 2, the preparation of 1-trimemylsilylphosphirane, 2.3, from cUoroemylbis(trimemylsilyl)phospriine, 2.1, is discussed. 1-trimemylsilylphosphirane may be converted to the parent phosphirane, 2.4, by methanolysis, and the coordination chemistry of these phosphines to iron(II), manganese(I), cobalt(III) and Cr(0) centres is discussed. The coordination of the parent phosphirane, 2.4, to the harder metal centres Fe(II) and Co(III) yields the bridging phosphifo-phosphhane dimeric complexes, 2.13 and 2.14, respectively. The reaction of phosphiranes with phosphides is also shown to yield 1,2-bis(phosphino)ethane. The manganese(I)-templated assembly of novel N2P 9 ane macrocycles from coordinated cis and trans 1,2-diaminocyclohexane precursors is reported in chapter 3. The efficiency of macrocycle formation is shown to be effected greatly by the different chelate conformations adopted by cis and trans diaminocyclohexane. Thus, the assembly of 9 ane N2P using the trans isomer is more efficient than the cis analogue. The reactivity of (9 ane N2P)Mn(CO)3 towards the decarbonylating agent, 4-methylmorpholine-N-oxide is shown to be selective, with only the carbonyl group trans to the phosphorus being removed. Attempts to liberate the macrocycle from the manganese centre using hydrogen peroxide and bromine result in the recovery of the free macrocycle, however, oxidation of the phosphorus atom is always observed. Chapter 4 reports the synthesis of seven and nine-membered triphosphines with two primary phosphines at each terminus is also reported. The coordination chemistry of these ligands to the d6 centres Fe(II) and Mo(0) is discussed, as is their reactivity with ring-closing agents, vinyl bromide and l-fluoro,2-iodobenzene.
23
Cromie, Sarah Jane Frances. "Chemistry and synthesis of polynuclear macrocycles." Thesis, Loughborough University, 2003. https://dspace.lboro.ac.uk/2134/35559.
Full textAbstract:
A series of di-, tetra- and octanuclear transition metal complexes of tetranucleating macrocyclic ligands derived from a Schiff-base [2+2] template condensation of 2,6-diformyl-4-methylphenol (dfmp) or 2,6-diformyl-4-tbutylphenol (tdfp) with 1,5-diaminopentan-3-ol dihydrochloride (dahp), H4L1 and H4L2 respectively, has been investigated. The characterisation of these complexes was achieved using infrared spectrometry, elemental analysis, FAB mass spectrometry and where possible single-crystal X-ray diffraction data. A study of the interaction of tetranickel(II) complexes of H4L1 and H4L2 with acetate and benzoate led to the structural determination of [Ni4(L2)(μ4-OH)(CH3CO2)3(CH3CO2H)(H2O)]·7H2O. The interaction of benzotriazolate and pyrazolate as coordinating anions with dinuclear copper and nickel complexes has led to the isolation of novel macrocyclic complexes with vacant coordination sites.
24
Bley, Escrich Jordi. "Propriétés rédox de nouveaux macrocycles polypyrroliques." Université Louis Pasteur (Strasbourg) (1971-2008), 2001. http://www.theses.fr/2001STR13097.
Full text
25
Lee, Sang-Hun. "Supramolecular architectures : macrocycles, catenanes and polyrotaxanes /." Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-08232007-112703/.
Full text
26
Zidane, Ismail. "Macrocycles tétrapyrazoliques synthèse et complexes métalliques /." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb376019979.
Full text
27
Pisciottani, Luca. "Synthèse de macrocycles et rotaxanes électroactifs." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0270/document.
Full textAbstract:
Le développement d'architectures moléculaires enchevêtrées (rotaxanes) est un sujet d'actualité en chimie supramoléculaire. Cette thèse examine la synthèse multi-étape de sous-unités de rotaxanes, notamment de composants macrocycliques électroactifs, et leur assemblage dans des structures moléculaires imbriquées. De nouveaux cycles à 31 et 35 chaînons à liaison hydrogène comprenant un motif récepteur bis (2,6-diamidopyridine) et une unité électroactive, à savoir du ferrocène ou de la triphénylamine, ont été synthétisés. Ces macrocycles ont été analysés par voltampérométrie cyclique, analyse par diffraction des rayons X sur cristal unique, ainsi que par spectroscopie RMN et spectrométrie de masse. Les interactions hôte-invité avec un acide complémentaire 5,5’-diéthylbarbiturique (Barbital) en tant qu’invité modèle ont également été étudiées par titrage spectroscopique par absorption électronique et RMN 1H. Les affinités de liaison étaient corrélées à la structure moléculaire. Des approches pour former des [2]rotaxanes, notamment en utilisant une réaction de matrice métallique active, où l'ion métallique joue le double rôle de matrice et de catalyseur, sont décrites. En particulier, les réactions de couplage de Huisgen ainsi que de Glaser catalysées au cuivre(I) ont été utilisées avec des bouchons de volumes variés. Dans une deuxième approche complémentaire de type "attache" de la formation de rotaxane, l'anneau électroactif a été formé directement entourant le composant de filetage servant de modèle. Cette méthodologie a permis d'obtenir deux [2] rotaxanes inédits via une réaction de "clipping" à cinq composants assistée par matrice, l'un des rotaxanes intégrant deux unités de ferrocène, tandis que l'autre comprenait deux unités de type triphénylamine. Les études de diffraction des rayons X sur cristal unique ont confirmé le caractère imbriqué des assemblagesDevelopment of interlocked molecular ring-on-thread architectures (rotaxanes) represents a central current topic in supramolecular chemistry. This thesis considers the multi-step synthesis of rotaxane subcomponents, notably electroactive macrocyclic components, and their assembly into interlocked molecular structures. Novel hydrogen-bonding 31- and 35-member rings comprising a bis(2,6-diamidopyridine) receptor motif and an electroactive unit, namely ferrocene or triphenylamine, were synthesized. These macrocycles were analyzed by cyclic voltammetry, single crystal X-ray diffraction analysis, as well as NMR spectroscopy and mass spectrometry. Host-guest interactions with a complementary 5,5’-diethylbarbituric acid (Barbital) as model guest were also studied by electronic absorption and 1H-NMR spectroscopic titrations. Binding affinities were correlated to molecular structure. Approaches to form 2rotaxanes, notably by employing an active metal template reaction, where the metal ion plays the dual role of template and catalyst, are described. In particular, the copper(I)-catalyzed Huisgen as well as Glaser coupling reactions were employed with a variety of bulky stopper groups. In a second complementary “clipping”-type approach to rotaxane formation, the electroactive ring was directly formed encircling the templating thread component. This methodology yielded two further novel [2]rotaxanes via a template-assisted five-component clipping reaction, one rotaxane integrating two ferrocene units while the other comprised two triphenylamine-like units. Single crystal X-ray diffraction studies confirmed the interlocked nature of the assemblies
28
Lucas, Jeremy. "Reaction dynamics of some pendant arm macrocycles /." Title page, contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phl9333.pdf.
Full text
29
Lopez, Periago Ana Maria. "Synthesis and supramolecular chemistry of trianglimine macrocycles." Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/804876/.
Full text
30
Willey, Alan David. "Substituted aza macrocycles as novel membrane precursors." Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316629.
Full text
31
Mammoliti, Oscar. "Bis-sulfonamide macrocycles as receptors for carboxylates." Thesis, University of Southampton, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438730.
Full text
32
Jantos, Katja. "Targeting G-quadruplex DNA with amide macrocycles." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613084.
Full text
33
Tatchell, Thomas. "Coordination chemistry of pendant aniline aza-macrocycles." Thesis, Cardiff University, 2005. http://orca.cf.ac.uk/56099/.
Full textAbstract:
The selective functionalisation of triazamacrocycles is investigated herein, with the focus on 1, 4, 7-triazacyclononane (tacn) The ligands tris (5-fluoro, 2- aminophenyl) 1, 4, 7-triazacyclononane (L1), tris (4-fluoro, 2-aminophenyl) 1,4, 7- triazacyclononane (L") and tris (3-fluoro, 2-ammophenyl) 1, 4, 7-triazacyclononane (L ) were studied. X-Ray crystal data was obtained for (L,)M (C104)2.x:MeCN where M=Mn,,/FeII/Ni"/CuII/Znn/CdII/Hgn, (L2)M (C104)2 xMeCN where M=Mn1I/Fe,I/NiII/CuII/ZnII/Cdn and (L3)M (C104)2 xMeCN where M=Mn,1/NiI,/Cun/Zn,I/Cd,,/Pb11 complexes. The (L,)Cu (C104)2 complex exhibits a rare dynamic Jahn-Teller effect in the solid state. Selected compounds exhibit an interesting capping mode by their perchlorate counterions, with threefold-hydrogen bonding through the oxygen to the amine protons. The (L3)Pb (C104)2 crystal structure exhibits a typical geometry which accommodates a stereoactive lone pair from the lead centre. The variable temperature 'H NMR of tris 1, 4, 7-(2- aminophenyl) 1, 4, 7-triazacyclononane zinc bis tetraphenylborate was carried out over 298K-193K and spectra are included within. All complexes characterized by 'H NMR, 13C NMR, 19F NMR, IR, UV and where appropriate Mossbauer spectroscopy. The investigation into the synthesis and chemistry of the novel sulphonamide pentaazamacrocycles 1 -(/-tolylsulphonyl), bis 4, 7-(2-aminophenyl) - 1, 4, 7-triazacyclononane (L4), l-(/7-methoxyphenylsulphonyl), bis 4, 7-(2- aminophenyl) -1,4, 7-triazacyclononane (L5), l-(p-fluorophenylsulphonyl), bis 4, 7-(2-aminophenyl) -1,4, 7-triazacyclononane (L6) and 1-(2-mesitylsulphonyl) bis 4, 7-(2-aminophenyl) 1, 4, 7- tnazacyclononane (L7). The complexation with differing transition metals afforded the relevant complexes and X-Ray data was obtained for (L4)Ni/Zn/Cd.MeCN (C104)2.MeCN, (L4)Pb(C104) (C104).2(MeCN), 2 (L4)Cu (C104)4,4MeCN MeOH, (L5)Ni/Zn MeCN (C104)2.MeCN, and (L6)Ni MeCN (C104)2 MeCN H20. The (L4)Zn/Hg/Pb.MeCN (C104)2 MeCN, (L5)Zn/Hg MeCN (C104)2.MeCN, (L6)Zn MeCN (C104)2 MeCN and (L7)Zn MeCN (C104)2 MeCN compounds exhibit an unusual amine pattern in the 'H NMR. This was further studied by variable temperature *H NMR over the range of 298K-418K. The (L4)Cu(C104)2 crystal structure shows two complexes of the same compounds crystallizing in the same cell, each with slightly differing dimensions, but both of square based pyramidal geometry. The (L4)Pb(C104) C104.2.MeCN crystal structure exhibits a typical geometry which accommodates a stereoactive lone pair from the lead centre The bis sulphonamide l-(2-aminophenyl)-bis 4, 7-(/xira-tolylsulphonyl) 1, 4, 7- triazacyclononane (L8) was also prepared and its complexation of L8Ni/Cu/Zn/Cd coordination chemistry expanded. The fluorinated 7V-aryl tacn class was expanded by producing bis and tris ortho meta para-fluorinated phenyl ligands. This selective methodology led to the development of a tri substituted tacn ring with meta and /wra-fluorinated aromatic rings. We report the electronic spectroscopic examination of the autocatalytic oxidative degradation of the macrocyclic aniline moiety over 120hrs. The synthesis of mono l-(5-fluoro, 2-aminophenyl) bis 4, 7, (2-aminophenyl) 1, 4, 7- tnazacyclononane (L9), and mono l-(4-fluoro, 2-aminophenyl) bis 4, 7, (2- aminophenyl) 1, 4, 7-triazacyclononane (L10) are reported. The X-Ray single crystal data was collected for (L9)Mn/Zn (C104)2 The synthesis of 1, 4-bis-(2-amino, 4-fluorophenyl) homopiperizene (Ln) and its X-Ray crystal structure of (LnNi 2 MeCN)(C104)2 is described The conversion of N, N' bis (2-aminophenyl) 1, 4-diazacycloheptane by reaction with p- toluenesulphonyl chloride afforded N, AT bis (2-tosylaminophenyl) 1, 4- diazacycloheptane (Lu). Reaction with nickel perchlorate afforded the neutral complex (L')Ni . This dianionic ligand is proposed as a porphyrin analogue.
34
Manning, Joanna M. "Synthesis and complexes of new selenoether macrocycles." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/173855/.
Full textAbstract:
The first known examples of alkyl Pt(II) complexes with macrocyclic selenoethers [PtMe2L] (L = [8]aneSe2 and [16]aneSe4) have been synthesised and characterised as part of a series of dimethyl Pt(II) complexes with selenoether ligands (L = MeSe(CH2)nSeMe, n = 2, 3; o-C6H4(CH2SeMe)2). A new series of [PtMe3I(κ2-L-L)] complexes has been synthesised and characterised, which includes the first examples of this type with macrocyclic selenoethers (L-L = o-C6H4(CH2EMe)2, E = Se, Te; MeC(CH2SeMe)3; [8]aneSe2 and [16]aneSe4). The first bridging ditelluroether trimethyliodo Pt(IV) complex, [(PtMe3I)2(MeTeCH2TeMe)] has also been characterised. [PtMe3(κ3-[16]aneSe4)]PF6 was isolated and characterised, which is the first cationic trialkylplatinum(IV) complex with a macrocyclic selenoether ligand, and an unusual example of κ3-[16]aneSe4 coordination. Five novel macrocycles containing a mixed O/Se donor set of the type OxSe2x, two small ring Se3 macrocycles and two Se2N macrocycles have been synthesised. Two methods of production have been investigated from the same precursors, a NaBH4 reduction and a low temperature Na/NH3 (l) reduction, demonstrating that reaction conditions are very important for determining preferred ring size and yields. The Se3 and Se2N macrocycles have been synthesised in multigram quantities, and crystal structures of two of these macrocycles have been obtained. The first examples of complexes with tridentate homoleptic selenoether macrocycles and tridentate Se2N macrocycles have been prepared and characterised. Platinum(II) dichloride complexes were prepared for L6-L9, but proved to be extremely poorly soluble. No evidence of platinum(II) complexation with methyl co-ligands was observed. Reaction of [PtMe3I] with L6-L10 resulted in the production of fac-coordinated, cationic Pt(IV) complexes of the type [PtMe3L]I. This geometry is confirmed by two crystal structures, of [PtMe3(L6)]I and [PtMe3(L9)]I. Cr(III) complexes of the type [CrCl3L] have been produced and characterised for L1, L6-10, and are generally hydrolytically sensitive, insoluble solids.
35
Andrianatoandro, Harimbola. "Macrocycles aromatiques complexants. Radiocristallographie et spectrométrie électronique." Bordeaux 1, 1992. http://www.theses.fr/1992BOR10582.
Full textAbstract:
De nouveaux macrocycles aromatiques complexants ont ete etudies en presence et en l'absence de cations, par diffraction des rayons x et photophysique (absorption electronique et fluorescence). Les interactions intramoleculaires entre chromophores (benzene, naphtalene et anthracene) et heteroatomes (n, s) dans le monocristal sont decrites et reliees aux proprietes photophysiques a l'etat solide et en solution. En particulier, pour deux cryptates d'argent (trois conformeres differents) et un complexe de sodium, l'influence de la position des cations sur la spectroscopie des ligands est abordee et discutee
36
Zamyatin, Andrey V. "A Photophysical Investigation of Nickel Tetrapyrrole Macrocycles." Bowling Green State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1134849222.
Full text
37
Bornet, Céline. "Synthèse et réactivité de nouveaux macrocycles séléniés." Dijon, 1998. http://www.theses.fr/1998DIJOS043.
Full textAbstract:
Ce mémoire apporte une contribution à la synthèse et à l'étude des propriétés complexantes de nouveaux macrocycles séléniés. Ceux-ci ont été pour la plupart construits autour d'entités rigides de type orthodisélénophénylène obtenues au départ d'un complexe du zirconium préparé antérieurement au laboratoire. Une chaine oxygénée a été dans chaque cas utilisée pour réaliser la cyclisation ou pour jouer le rôle d'espaceur entre deux entités. A des fins de comparaisons, d'autres systèmes construits au départ de ligands orthothio-séléno ou orthothio-tellurophénylène ont également été synthétisés. Les ligands obtenus ont été caractérisés par spectrométrie de masse et RMN multinoyaux. La structure de trois d'entre eux a été déterminée par diffraction de rayons X. La réactivité des différents macrocycles synthétisés a été testée vis-à-vis de divers ions métalliques (palladium (ii), platine (ii), argent (i), or (i) et mercure (ii)), ainsi que du molybdène et tungstène hexacarbonyle. Des complexes stables ont ainsi été obtenus dans lesquels les métaux sont fixes sélectivement sur les atomes de sélénium. Deux structures ont été résolues par diffraction de rayons X. En particulier, le premier complexe cationique du palladium associant deux macrocycles séléniés par l'intermédiaire d'un atome métallique a pu être synthétisé et caractérisé. Parmi les possibilités offertes par les ligands synthétisés, nous avons pu montrer que les macrocycles tétraséléniés sont aptes à extraire des ions mercure (ii) d'une solution aqueuse. Ils permettent également la complexation de molécules polaires telles que l'acétonitrile ou le maléonitrile.
38
PULPOKA, BUNCHA. "Synthese d'oxa-aza macrocycles derivant du calix4arene." Université Louis Pasteur (Strasbourg) (1971-2008), 1997. http://www.theses.fr/1997STR13030.
Full textAbstract:
Le travail presente dans cette these a consiste en la synthese de ligands macrocycliques polytopiques et en l'etude de leurs proprietes complexantes. Ces ligands derivent du calix4arene et comportent des chaines (n,o)-ether-couronnes et des motifs cryptands. Cet arrangement moleculaire se fait de part et d'autre d'un calix4arene en conformation 1,3-alternee. Dans un premier temps nous avons synthetise des calix4arene-di(aza-benzo)couronne-ether-couronnes-6 comportant une chaine polyethylene glycolique d'un cote du calixarene et une chaine (n,o)-ether-couronne de l'autre. Le double-pontage du calix4arene se fait par une premiere condensation 1+1 avec la chaine (n,o)-ether-couronne suivie d'une seconde condensation 1+1 avec le pentaethylene glycol. Ces calix4arene-di(aza-benzo)couronne-ether-couronnes-6 sont des recepteurs ditopiques susceptibles de complexer simultanement un cation dur et un cation mou. Dans un deuxieme temps nous avons synthetise un intermediaire precurseur des calix4arene mono couronne cryptands et calix4arene-bis-cryptands. Nous avons en particulier utilise le groupement boc comme groupement protecteur plus facile a enlever que le groupement ts dans le deprotection des atomes d'azote. Nous avons donc etudie leurs proprietes de complexation vis a vis des alcalins et de l'ammonium. Nous avons mis en evidence des complexes mono- et binucleaires ainsi que des complexes heterobinucleaires. Nous avons en particulier montre que les sites cryptands piegent preferentiellement na#+, k#+ et nh#4#+ alors que les ether couronnes-6 piegent rb#+ et cs#+
39
Kaiser, Achim. "Physicochemical Properties and Synthesis of Oligothiophene Macrocycles." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-64614.
Full text
40
Cai, Sheng. "Magnetic resonance investigations of iron tetrapyrrolic macrocycles." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279817.
Full textAbstract:
¹H NMR and EPR techniques were used to investigate the electron spin distribution and electronic ground state in several iron tetrapyrrolic macrocycles. The first macrocycle studied is corrole, including [(Me₈C)FeCl] (Me₈C = 2,3,7,8,12,13,17,18-octamethylcorrole) and [(7,13-Me₂Et₆C)FeCl] (7,13-Me₂Et₆C = 7,13-dimethyl-2,3,8,12,17,18-hexaethylcorrole) and four meso-substituted corrolates--[(TPCorr)FeCl], [(4-NO2TPCorr)FeCl], [(4-MeOTPCorr)FeCl] and [(TPCorr)FeClO₄] (TPCorr = 5,10,15-triphenylcorrole). These chloroiron corrolates were all found to be S = 3/2 intermediate-spin iron(III) π cation radical complexes, with the corrole radical strongly antiferromagnetically coupled to the spins of the iron, leading to an overall spin of 1 and large negative π spin densities on the meso positions. Upon addition of imidazole ligands, [(Me₈C)FeCl] and [(7,13-Me₂Et₆C)FeCl2] change to bis imidazole low-spin iron(III) π cation radical species at low temperature. There is little or no ferromagnetic coupling between the radical and the iron center, resulting in large position pi spin densities on the meso positions. The binding of cyanide to [(7,13-Me₂Et₆C)FeCl] causes autoreduction of the complex. An excess of cyanide in the solution can reduce the bis-cyanide complex, a low-spin iron(III) π cation radical which is produced first upon addition of cyanide, to the mono-cyanide complex, which is a normal low-spin iron(III) five-coordinate complex. The redox reaction occurs on the corrole ring instead of at the iron center. Proton relaxation times (T₁ and T₂) of a pyrrole-CH₃ peak from the heme domain of the chicken liver sulfite oxidase were measured by NMR methods. From the relaxation times, it is found that the sulfite oxidase enzyme tumbles as the whole protein rather than the larger Mo domain and the smaller heme domain tumbling somewhat independently. The last macrocycles investigated are chlorins and mono-oxochlorin. Both high-spin tetraphenylchlorinatoiron(III) chloride (TPCFeCl) and octaethylchlorinatoiron(III) chloride (OECFeCl) and their low-spin complexes with different imidazole and pyridine ligands were studied by NMR and EPR. The full peak assignments were made for all high-spin and low-spin species from COSY, NOESY, NOE difference and saturation transfer experiments. The NMR results show that, like TPPFe(III) and TMPFe(III) complexes, the low-spin TPCFe(III) complexes change their ground state from (dxy)²(dxzdyz)³ to (dxzdyz)⁴(dxy)¹ with decrease in the donor strength of the axial ligands, while OECFe(III) complexes keep their ground state unchanged (always (dxy)²(dxydyz)³) with different axial ligands in the temperature range of NMR experiments (+30°C to -90°C)). However, EPR data show that both TPCFe(III) and OECFe(III) complexes have the trend of change to (dxzdyz)⁴(dxy)¹ ground state with weak donor ligands (such 4-cyanopyridine). The electronic structure of [OECFe(t-BuNC)₂]⁺ is the (dxzdyz)⁴(dxy)¹ ground state with a low-lying (dxy)²(d xzdyz)³ excited state. The chlorin ring of [OECFe(tBuNC)₂]⁺ is probably ruffled, as in [OEPFe(t-BuNC)₂]⁺. The NMR spectrum of [OECFe(t-BuNC)₂]⁺ is characterized by the large downfield shift of the pyrrolene protons, indicating the involvement of the A-1 orbital in the spin distribution mechanism. [mono-oxo-OECFe(Im-d₄)₂]Cl (mono-oxo-OEC = 2-oxo-3,3',7,8,12,13,17,18-octaethyl-chlorin) is a low-spin Fe(III) complex with (dxy)²(dxzdyz)³ ground state. The pattern of the chemical shifts of the pyrrole-CH2 and meso protons is similar to that of [OECFe(Im-d₄)₂]Cl, except that more peaks were observed due to its lower symmetry. Finally, DFT calculation on high-spin iron (III) chlorin was carried out to predict the Fermi contact shifts and spin distribution mechanism.
41
Heberlig, Graham William. "Harnessing Natural Product Biosynthesis to Access Macrocycles." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39260.
Full textAbstract:
Macrocyclic natural products are conformationally restricted molecules that often have improved ability to bind with high affinity and selectivity on a target. Within macrocycle chemistry, macrolactone formation is a particularly challenging transformation and has spurred the development of highly diverse synthetic strategies. A key strategy that is missing is a chemoenzymatic approach to this challenge, and the logical place to look for such a catalyst is the thioesterases (TEs) from the biosynthetic pathways that generate these molecules in Nature. These TEs are α/β-hydrolases containing an active site serine or cysteine and a conserved histidine/aspartate catalytic diad. The research presented here describes the development of two related TE domains from resorcylic acid lactone polyketide synthases found in various fungi. Unlike their bacterial counterparts these macrocyclization catalysts have proven to be stereotolerant with regard to the secondary alcohols involved in macrocyclization. Further work has demonstrated that they are also amenable to generating 12- to 18-member macrolactones. These TE domains can also catalyze macrolactam and cyclic depsipeptide formation, setting the stage for these enzymes to serve as a platform for catalyst development. The development of 2,3-diaminopropionate (DAP) incorporation in place of the active site Ser to trap acyl-enzyme intermediates was used to structurally characterize the formation of a macrocyclic trimer. This technique will be broadly applicable to characterizing other TEs. Overall the research presented here lays the foundation for the long term development of TEs as macrocyclization biocatalysts.
42
Le, Derf Franck. "Macrocycles complexants électrochimiquement commandables incorporant l'unité tétrathiafulvalène." Angers, 1998. http://www.theses.fr/1998ANGE0021.
Full textAbstract:
Une stratégie de synthèse de récepteurs macrocycliques associant a une sous unité électroactive tetrathiafulvalene (ttf), des chaines aza-, oxa- ou thia-polyethers de tailles variées a été développée. La capacite de ces systèmes à piéger divers cations métalliques a pu être déterminée a l'aide de différentes méthodes (spectrometrie de masse, résonance magnétique nucléaire, spectroscopie uv-vis), certains complexes ayant par ailleurs été caractérisés par diffraction aux rayons-x. La maitrise recherchée de processus de complexation / expulsion du métal en fonction du degré d'oxydation de l'unité ttf, a pu être contrôlée par voltammetrie cyclique. Ainsi, il a pu être mis en évidence que ces récepteurs electrochimiquement commandables, disposent de constantes d'association élevées a l'égard de divers cations métalliques lorsque l'unité ttf est neutre, faible lorsqu'il est oxyde a l'état radical-cation, et enfin nulle lorsqu'il est dicationiqueA strategy for the synthesis of macrocyclic receptors associating aza-, oxa- or thia-polyether chains of various sizes to an electroactive tetrathiafulvalene (ttf) subunit has been developed. The ability of these systems to trap various metal cations was determined using different methods (mass spectrometry, nuclear magnetic resonance, uv-vis spectroscopy), and some of the complexes were also characterised by x-ray diffraction. The desired control of the complexation/expulsion process of the metal as a function of the oxidation state of the ttf unit could be monitored by cyclic voltammetry. Thus, it was shown that these electrochemically controllable receptors have high association constants with various metal cations when the ttf unit is neutral, low when it is an oxide in the radical-cation state, and finally zero when it is dicationic
43
Sakellariou, Efstathia G. "Seco- and solitaire porphyrazines : design, synthesis and photophysical evaluation." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270124.
Full text
44
Bakboord, Joan Vanessa. "Synthesis and spectroscopic studies of novel phthalocyanines-toward new electronic absorption properties." Thesis, University of East Anglia, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323290.
Full text
45
Tseki, Potlaki Foster. "Metal complexes of thiophene analogues of crown ethers and cryptands." Thesis, Nottingham Trent University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386053.
Full text
46
Mousley, David P. "The application of bis(benzo)-crown ethers as multireceptors." Thesis, University of Newcastle Upon Tyne, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295075.
Full text
47
Korich, Andrew. "Phenylene Ethynylene and Phenylene Imine Macrocycles As Precursors for Organic Nanotubes." ScholarWorks @ UVM, 2009. http://scholarworks.uvm.edu/graddis/127.
Full textAbstract:
Single walled carbon nanotubes (SWCNTs) have unique physical, optical and electronic properties. Current production methods provide SWCNTs as a polydisperse mixture, with respect to helicity, diameter and length, and cannot be tuned to yield a discrete SWCNT isomer. A bottom up approach would yield a single SWCNT, which would allow for a better understanding of how chemical modification affects a carbon nanotube’s properties. Synthesis by this route has yet to be accomplished. Phenylene ethynylene macrocycles were synthesized by a stepwise linear fashion and cyclooligomerization. These macrocycles are Diels-Alder cycloaddition precursors for a rational synthesis of a (9,0) SWCNT segment. Additionally, these macrocycles are of interest due to their highly conjugated two dimensional networks, which gives rise to high quantum efficiency. Therefore, the optical properties of these macrocycles were studied in several of solvents. In addition, a novel reductive imination was examined and used to synthesize a series of phenylene imine macrocycles. These systems could be precursors towards organic N-doped SWCNTs by either a hetro-Diels-Alder cycloaddition or pyrrole ring formation.
48
Huez, Philippe. "Synthèses et analyses conformationnelles de macrocycles aza-β³-peptidiques contenant des atomes d'azote chirogéniques." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S072/document.
Full textAbstract:
Le travail présenté dans ce mémoire est consacré à la synthèse de cycles pseudopeptidiques construits à partir d'aza-β³-aminoacides, et à la détermination des conformations adoptées par ces cycles. Le travail réalisé a permis de montrer que les cycles obtenus à 8, 16 et 24 liaisons adoptent des conformations privilégiées dans lesquelles la configuration relative des atomes d'azote chiraux est fixée en dépit du phénomène d'inversion pyramidale associé à la structure électronique de cet élément chimique, en réponse à des contraintes structurelles qui varient selon la taille du macrocycle. Ces cycles existent alors sous la seule forme de deux invertomères en équilibre. La constante de vitesse de cet équilibre, qui est indiscernable de la barrière d'inversion pyramidale des atomes d'azote, est maintenue à des valeurs étonnamment faibles par les contraintes conformationnelles. L'étude de ces macrocycles originaux dans le domaine de la chiralité a permis d'apporter en particulier des résultats nouveaux concernant l'influence de l'encombrement stérique des chaînes latérales sur la vitesse d'inversion pyramidale des atomes d'azote, mais aussi sur le transfert de chiralité d'éléments d'asymétrie exocycliques vers la séquence chirale du squelette, et enfin de montrer également l'intérêt des nouveaux cycles à 8 chaînons à travers l'étude de leur conformationThe work depicted here is devoted to the synthesis of pseudopeptides built from aza-β³-aminoacid units, and to their conformational analysis. The results show that the cycles with 8, 16, and 24 bonds each adopt a ground conformation where the relative configuration of the chiral nitrogen atom is fixed in response to specific structural constraints, and despite the nitrogen pyramidal inversion phenomenon. The cycles just undergo equilibrium between two invertomeric forms, and the energetic barrier associated with the macrocycle inversion reveals surprisingly slow considering the size of the compounds. The influence of steric crowding of the side chains on the inversion rate has been carefully studied, but also the transfer of chirality from exocylic elements towards chirotopic nitrogen atoms inside the backbone. A specific chapter is devoted to the 8-membered rings, that reveal the interest of these newly described compounds in the domain of nitrogen chirality
49
Klein, Jörg Martin. "Dynamic combinatorial chemistry of hydrazone and disulfide macrocycles." Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/252248.
Full text
50
Edwards, David Ryan. "Towards liquid crystalline [3 + 3] Schiff-base macrocycles." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31612.
Full textAbstract:
Conjugated Schiff-base macrocycles are interesting compounds of interest as platforms for catalysis, the preparation of novel synthetic ion channels and potentially as porous or tubular discotic liquid crystals. The preparation of organic macrocycles is typically low yielding, with polymerization competing with cyclization; the use of imines derived from the condensation of an aldehyde and an amine provides a means by which to conduct cyclizations under thermodynamic control and thereby improve yields. The use of difunctional aldehydes and amines allows for the formation of macrocycles in high yields without the need for high-dilution conditions. Two highly substituted dialdehydes also bearing phenolic and aikyl functionalities were prepared by several routes in an effort to obtain macrocycle precursors. These precursors were characterized and subsequently employed to prepare [3+3] Schiff-base macrocycles with a large number of appended aikyl and alkoxy substituents in hopes that they would display discotic liquid crystallinity.
A series of highly substituted [3+3] Schiff-base macrocycles was prepared and characterized by ¹H NMR, ¹³C NMR, UV-Vis, and IR spectroscopies in addition to MALDI-TOF mass spectrometry. The thermal properties of these macrocycles were also examined, and they were not found to display liquid crystalline mesophases either by differential scanning calorimetry or polarizing optical microscopy. A crystal structure of one of the macrocycles was obtained and was found to display structural features not previously observed in related macrocycles.Science, Faculty of
Chemistry, Department of
Graduate