Dissertations / Theses on the topic 'Metal complex'
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McQuaid, Michael James. "Spectroscopic characterization of metal-based complexes and metal-based complex oxidation processes." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/30334.
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Sooksawat, Dhassida. "Transition metal complex-based molecular machines." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/10045.
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Inspired by the performance and evolutionarily-optimised natural molecular machines that carry out all the essential tasks contributing to the molecular basis of life, chemists aim towards fabricating synthetic molecular machines that mimic biological nanodevices. The use of rotaxanes as a prototype for molecular machines has emerged as a result of their ability to undergo translational motion between two or more co-conformations. Although biological machines are capable of complex and intricate functions, their inherent stability and operational conditions are restricted to in vivo. Synthetic systems offer a limitless number of building blocks and a range of interactions to be manipulated. Transition metal-ligand interactions are utilised as one strategy to control the directional movement of submolecular components in artificial machines due to their well-defined geometric requirements and significant strength. This thesis presents new externally addressable and switchable molecular elements for transition metal complexed-molecular machines involving an acid-base switch. The proton input that induces changes to cyclometallated platinum complexes can be exploited to control exchange between different coordination modes. The development of the pH-switchable metal-ligand motif for the stimuli-responsive platinum-complexed molecular shuttle has also been explored. The metal-directed self-assembly of tubular complexes were studied in order to develop self-assembled rotaxanes. A series of metal building blocks was explored to extend the scope for a tube self-assembly.
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McCarthy, David Lee. "Creating Complex Hollow Metal Geometries Using Additive Manufacturing and Metal Plating." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/43530.
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Additive manufacturing introduces a new design paradigm that allows the fabrication of geometrically complex parts that cannot be produced by traditional manufacturing and assembly methods. Using a cellular heat exchanger as a motivational example, this thesis investigates the creation of a hybrid manufacturing approach that combines selective laser sintering with an electroforming process to produce complex, hollow, metal geometries. The developed process uses electroless nickel plating on laser sintered parts that then undergo a flash burnout procedure to remove the polymer, leaving a complex, hollow, metal part. The resulting geometries cannot be produced directly with other additive manufacturing systems.
Copper electroplating and electroless nickel plating are investigated as metal coating methods. Several parametric parts are tested while developing a manufacturing process. Copper electroplating is determined to be too dependent on the geometry of the part, with large changes in plate thickness between the exterior and interior of the tested parts. Even in relatively basic cellular structures, electroplating does not plate the interior of the part. Two phases of electroless nickel plating combined with a flash burnout procedure produce the desired geometry. The tested part has a density of 3.16g/cm3 and withstands pressures up to 25MPa. The cellular part produced has a nickel plate thickness of 800µm and consists of 35% nickel and 65% air (empty space). Detailed procedures are included for the electroplating and electroless plating processes developed.Master of Science
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Schnepp, Zoé. "Control of morphology in complex metal oxides." Thesis, University of Bristol, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504239.
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The exceptional electronic, magnetic, optical and catalytic properties demonstrated by many ceramic materials when confined to the nano-scale are well established. However, the synthesis of complex metal oxide nanowires and nanoparticles is notoriously problematic due to the difficulty of controlling homogeneity and achieving the correct stoichiometry. This thesis describes a new paradigm in solid-state synthesis. By organizing precursor metal cations within a gel of the structural biopolymer alginate. initial nucleation of preceramic crystalline phases is restricted to the nano-scale. On further calcination, the decomposition products of the biopolymer prevent sintering of these nanoparticles before the final crystallographic transformation to the ceramic product.
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Yao, Jing Wen. "Systematic structural studies in metal complex chemistry." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/5055/.
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A procedure is presented for detecting geometrical preferences, deformations and interconversion pathways between different geometries for the transition metal coordination sphere ML(_n). A discrepancy index [R(_ang)(x)] was proposed initially to address the problems of dimensionality and permutation complexity in the systematic analysis of coordination sphere geometry with higher coordination numbers (n > 7). But it can also be used generally for the lower coordination numbers. A set of standard geometries for coordination numbers 2-9 are presented and the angles between the center point and each vertex for the polyhedra which are used to describe the coordination sphere geometries for coordination numbers 7-9 are idealised. These angles correspond to the metal-ligand valence angles in the coordination complex and are used as the standard values to measure the deviation of a real coordination sphere in the complex from these standard polyhedra. Geometry of each coordination sphere (ML(_7-9)) from the Cambridge Structural Database (CSD) is identified by the calculations of R(_ang)(x) values. Also the unique enumeration numbers of the ligands corresponding to each geometry can be derived over the n! ligand permutations. The different geometrical clusters and interconversion pathways from one to another are mapped in a designed two-dimensional plot. The symmetry coordinates and principal component analysis are initially applied in these higher coordination number systems. They not only map the clusters represented to those standard geometries in the different symmetric point groups but also provide and confirm the interconversion pathways between the different geometries. The other systematic study involves the analysis and correlation of the metal σ-π bond in the transition metal alkyne and alkene complexes from the CSD. Geometrical features of this specific bond are examined in the view of structure and some useful correlation between the key geometrical parameters are defined. Finally, X-ray crystal structure determinations are briefly described and the crystal structures of ten transition metal compounds in coordination numbers 4-6 are presented.
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Monti, Mauro. "Metal ligand complex syntheses for imaging applications." Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/101041/.
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This thesis describes an investigation into the roles and effects of nitrogen-donor chelating ligands and complexes containing metal centres as tools for molecular imaging. Chapter 1 gives a brief introduction to Positron Emission Tomography (PET) imaging,the radionuclides and metal centres currently available for therapeutic use, and a discussion and comparison between metal and organic-based contrast agents. Chapter 1 also contains an introduction to macrocycles and their role as ligands, with particular focus on azamacrocycles and their applications. Finally, a brief introduction to luminescence spectroscopy and optical imaging is made. Chapter 2 reports the synthetic procedures used, and gives characterisation data for the compounds synthesised and discussed in subsequent chapters. Chapter 3 investigates the role of the triazine core of the azamacrocycles, showing some compounds of biological interest and the synthesis of new ligands and complexes based on a tetraazamacrocycle (DO3A) moiety with a triazine core. One example has been successfully used to study the coordination chemistry and structure of different metal centres, while another has shown promise with a potential application in mimicking dipyridamole compounds. Moreover it has been conducted a study to determinate the empirical formula and the nature of the complexes in solution. Chapter 4 contains an introduction to the benzothiazole group, which has relevance in the study of Alzheimer's disease as it is a biological marker for metal-dependant formation of Aβ plaques. The synthesis of new ligands derived from several macrocycles (including those reported earlier, and those containing an acyclic moiety with a benzothiazole core) are reported, including procedures to produce complexes of lanthanides and PET-active metal centres including copper, vanadium and gallium. Benzothiazole ligands and complexes have been characterised by fluorimetry, allowing discussion of the role of the ligand.
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Yadnum, Sudarat. "Tailoring complex heterogeneous metal-organic framework structures." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0299/document.
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Dans cette thèse, de nouvelles stratégies pour la préparation de matériaux de type Metal-Organic-Frameworks (MOF) ont été étudiés et développés. L’électrodeposition bipolaire indirecte (IBED) a été utilisé pour préparer ZIF-8 et HKUST-1 sur des substrats métalliques de façon simple et avec une sélectivité spatiale. Ce concept devrait pouvoir être généralisée pour la synthèse de nombreux autres composés MOF, permettant ainsi une synthèse pas chère et verte, conduisant à de nouvelles générations de composites de type Janus basés sur des MOFs. En outre, des électrodes avec une structure hiérarchique macro-/ microporeux de HKUST-1 ont été préparées par une technique de dissolution-dépôt électrochimique. L'approche de synthèse mis au point est très pratique en ce qui concerne la durée des expériences, et ouvre diverses applications pour les MOFs. Enfin des nanoparticules de métaux nobles sur un substrat à base de MIL-101 ont été préparées comme la dernière partie de l'étude expérimentale par dépôt colloïdal. Ce concept peut être généralisé pour la synthèse d'autres composites nanoparticules métalliques / MOF, et pourrait améliorer l'activité catalytique des MOFs. En dehors de l'étude expérimentale, afin de comprendre mieux la catalyse de matériaux MOF, le comportement catalytique de Cu (II) dans le MOF-505 a été théoriquement étudié pour la réaction d'aldolisation Mukayiama par la théorie de densité fonctionnelle et comparé à celui d'un autre catalyseur, Cu-ZSM-5. En outre, le comportement catalytique d'amas homo- et hétéro-bimétalliques, qui sont des complexes métalliques qui représentent les agrégats métalliques dans les MOFs, a également été étudié théoriquement pour la réaction de cycloaddition de dioxyde de carbone et des oxydes d'éthylèneIn this thesis, new strategies for the preparation of Metal 0rganic Frameworks (MOF) materials with designed structures were studied and developed. Indirect bipolar electrodeposition (IBED) was used to prepare ZIF-8 and HKUST-1 on metal substrates in a straightforward and site-selective way. This concept is expected to be able to be generalized for the synthesis of many other MOF compounds, thus allowing a cheap and green synthesis, leading to new generations of MOF-based Janus-type composites. Furthermore, rationally designed hierarchical macro-/microporous HKUST-1 electrodes were prepared via an electrochemical dissolution-deposition technique. The developed synthesis approach is very practical in terms of the time consumption, and opens up MOFs for various applications. Finally, MIL-101-supported noble metal nanoparticles were prepared as the last part of the experimental studies via a simple colloidal deposition technique. This concept might be generalized for the synthesis of other metal nanoparticle/MOF composites, and might improve the catalytic activity of MOFs. Apart from the experimental study, in order to gain a deeper insight into the catalysis of MOF materials, the catalytic behavior of Cu(II) in the paddle-wheel unit of MOF-505 was theoretically investigated for the Mukaiyama aldol reaction via the density functional theory and compared to that of another catalyst, Cu-ZSM-5 zeolite. Besides, the catalytic behavior of homo-metallic clusters and hetero-bimetallic clusters, that are the metal complexes representing the metal clusters in MOFs, were also theoretically investigated for the cycloaddition reaction of carbon dioxide and ethylene oxides
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Perenlei, Ganchimeg. "Energy band engineering of complex metal oxides." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/90056/1/Ganchimeg_Perenlei_Thesis.pdf.
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This doctoral studies focused on the development of new materials for efficient use of solar energy for environmental applications. The research investigated the engineering of the band gap of semiconductor materials to design and optimise visible-light-sensitive photocatalysts. Experimental studies have been combined with computational simulation in order to develop predictive tools for a systematic understanding and design on the crystal and energy band structures of multi-component metal oxides.
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Gourdon, André. "Synthèse et étude structurale de clusters de fer contenant un hétéroatome du type carbure, nitrure, phosphure." Paris 6, 1986. http://www.theses.fr/1986PA066404.
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Jones, Michael David. "Trimethylenemethane and oxodimethylenemethane metal complexes." Thesis, University of Leicester, 1986. http://hdl.handle.net/2381/33764.
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Chapter 1 reviews the literature concerning trimethylenemethane and oxodimethylenemethane metal complexes and their r?le in organic synthesis. The preparation and characterisation of ?4-trimethylenemethane metal complexes of iridium, rhodium, osmium and ruthenium are presented in Chapter 2, together with the molecular structure of three of these complexes which establishes the presence of the ?4-trimethylenemethane ligand. The room temperature 1H n.m.r. spectra show the expected features for a static structure and no sign of rotation of the trimethylenemethane ligand was observed at higher temperatures. Preliminary investigation into the reactivity of these trimethylenemethane complexes is detailed in Chapter 3. A series of cationic ?4-trimethylenemethane complexes are prepared by the reaction of [Ir{?4-C(CH2)3}C1 (CO)(PPh3)] with silver hexafluorophosphate in the presence of a donor ligand such as carbon monoxide or ethene. The reactions of these cationic complexes with neutral and anionic nucleophiles are investigated and show that displacement of other donor ligands or attack on co-ordinated carbonyl and ethene ligands occurs, rather than attack at, or displacement of the trimethylenemethane ligand. Chapter 4 describes the reaction of 3-trimethylsilyl-2-(methyl- sulphonyloxymethyl) prop-l-ene with d10-metal complexes of platinum, palladium and nickel. The isolation of ?3-2-trimethylsilylmethylallyl palladium and platinum complexes are of interest since they are postulated intermediates implicated in the generation of the catalytic species [Pd (?3-trimethylenemethane) (PPh3)2]. The d10 -nickel complex [Ni{P(OEt)3}4] catalyses the cycloaddition of trimethylenemethane to electron-deficient alkenes and imines, the latter reaction affords a high yield synthesis of 4-methylenepyrrolidines. The final Chapter describes the reactions of 3-chloro-l-(trimethyl-silyl)propan-2-one and 3-chloro-2-(trimethylsiloxy)prop-l-ene with low-valent metal complexes to afford oxodimethylenemethane complexes of platinum, iridium, and osmium. The molecular structure of two of these complexes establishes the presence of an ?3-oxodimethylenemethane ligand. The silylenol ether, 3-chloro-2-(trimethylsiloxy)prop-l-ene was readily prepared from 3-chloro-l-(trimethylsilyl)propan-2-one, the isomerisation being catalysed by a number of low-valent metal complexes.
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Marzak, Saïd. "Complexes du cuivre (i) construits sur le fragment (ms::(4))**(2-) (m=mo,w) : role du ligand thiocyanate dans l'edification de composes heterometalliques a structure infinie." Paris 6, 1988. http://www.theses.fr/1988PA066401.
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Preparation de complexes du type (nr::(4))::(n)(cu::(4)(ncs)::(4)ms::(4)), m=mo, w, r=me, et et n=2 ou 3. Selon la taille du cation, obtention de macrostructures bidimensionnelles ou tridimensionnelles; l'insertion du cation pph::(4)**(+) conduit a la formation d'une structure infinie de chaines lineaires
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Atkins, Andrew J. "Studies on transition metal macrocyclic complexes." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/11664.
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Patino, Midori Amano. "Topochemical manipulation of some complex transition metal oxides." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:e312bf34-98d5-4818-bb50-fd8772688a1d.
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This thesis is comprised of three parts. The first part concerns the investigation of the topochemical reduction of LaSrNiRuO6 in order to prepare LaSrNiRuO4 via anion deintercalation. The second part discusses the oxide-for-hydride anion exchanges performed in SrV1-xTixO3, and the resulting SrV1-xTixO2-yH1+y reduction products. Finally, the results from redox-neutral topochemical cation exchange reactions conducted in the three-dimensional perovskite structure of NaTaO3 are presented along with the characterisation of a novel product of composition Ni0.5TaO3. The topochemical reduction of LaSrNiRuO6 using CaH2 was carried out to produce a novel extended oxide phase with composition LaSrNiRuO4. This phase is composed of sheets of apex-linked Ni1+O4 and Ru2+O4 squares in a checkerboard ordered arrangement. To the best of our knowledge, this material is the first example of a B-cation ordered infinite-layer oxide phase. The low oxidation states of the transition-metal cations are confirmed by DFT calculations from which a spin moment S = ½ is determined for the nickel while the ruthenium centres adopt an intermediate-spin S = 1 configuration. LaSrNiRuO4 behaves paramagnetically at room temperature. However, upon cooling (T < 250 K) a phase transition is observed in which the nickel spins interact ferromagnetically, while the ruthenium cations appear to undergo a change in spin configuration to a diamagnetic spin state. A possible explanation is given for this observation based on an ordered arrangement of local Jahn-Teller distortions. While investigating the preparation of LaSrNiRuO4, it was observed that different samples of the LaSrNiRuO6 starting materials exhibited markedly different reactivity. The observed differing reactivity is inconsistent with the crystal structure and composition of the LaSrNiRuO6 samples, from which all the materials are identical. Careful investigation of the X-ray diffraction data collected from the LaSrNiRuO6 materials revealed that the reactivity of the samples is a consequence of the microstructure. By quenching or slow-cooling the materials during their synthesis, the size of the crystalline domains formed is affected and this in turn is observed to define the extent to which the topochemical deintercalation of oxide anions takes place. A mechanism to explain this effect is presented in which the greater 'plasticity' of small crystalline domains helps to limit the influence of lattice strain during the reaction. Similar with the observations for the LaSrNiRuO6 phases, it was found that the reactivity of SrV0.95Ti0.05O3 samples towards topochemical oxide-for-hydride exchange is also determined by the characteristics of the starting materials. The cooling rate can lead to phase segregation in SrV0.95Ti0.05O3 samples which in turn affects the reduction behaviour. A modification of the energy profile for the oxide-for-hydride exchange in SrV1-xTixO3 phases is proposed on the basis of the electronic configuration that the transition-metal cations adopt upon reduction (d2,V3+ and d1,Ti3+). Finally, topochemical exchange reactions can also be carried out between cations in complex transition metal oxides when the mobility of the species to be exchanged is sufficiently greater with respect to the host lattice. The preparation of Ni0.5TaO3 from exchange of Na+ by Ni2+ in NaTaO3 represents a synthetic approach not yet widely explored in the long-standing challenge that the preparation of magnetoelectric multiferroic materials represents. The topochemical reactions studied in this work highlight the possibility of directing and modifying the product phases, by tuning features of the reagents. This is in contrast with the limited control available in thermodynamic processes.
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Holdsworth, Alistair F. "Novel metal complex fire retardants for engineering polymers." Thesis, University of Bolton, 2015. http://ubir.bolton.ac.uk/697/.
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The aims of this project were to develop non-halogenated, non-toxic and environmentally benign synthetic inorganic compounds capable of imparting flame retardant and/or synergistic activity with selected conventional flame retardants to selected engineering polymer systems. Following a comprehensive literature survey with specific focus centered upon the degradation and fire retardancy of polyamide 6,6 (PA66), an initial study of the effect of several metal oxalates on the burn rate of impregnated cotton in combination with sources of bromine and phosphorus was performed, with some promising synergistic activity detected with the former. Following this, a matrix of potential non-toxic inorganic flame retardant candidates (FRCs) was devised from a range of non-toxic, water-soluble precursors. And 180 FRCs were successfully synthesised and a cursory characterisation was conducted using X-Ray Fluorescence (XRF). These were screened for potential flame retardant properties with polyamide 6,6 (PA66) as a suitable engineering polymer. PA66 pellets were powdered and mixed with each FRC in 3:1 mass ratio, and subjected to simultaneous differential thermal analysis/thermogravimetric analysis (TGA/DTA), to which a range of selection parameters were applied, assessing their stability and char-forming potential. All FRCs which did not conform to these conditions were eliminated, reducing the number to 60. Differential mass analysis was performed on TGAs of the 60 FRCs to better define their char promotion potential in PA66, thereby narrowing these down to 16 samples: aluminium, zinc and tin (II) tungstates (AlW, ZnW and SnW respectively); zinc molybdate (ZnMo); iron aluminate (FeAl); iron (III) hypophosphite (FeHP); zinc oxalate (ZnOx); three stannic metal nitrite complexes (SnMNO where M = Mn, Cu or Zn), tin (II) oxide (SnO), hydrogenphosphite (SnH2PO3), triphosphate (SnTP) and phenylphosphonate (SnPhPO3); and tin (IV) silicate (SnSi). The 16 selected were synthesised on a larger scale and fully characterised, of which 6 were discounted due to difficulties in synthesis scaling, or characterisation. The final 10 FRCs were selected for small-scale fire testing in PA66 (at 5 wt%), using UL94, LOI and cone calorimetry with additional analysis provided by TGA/DTA. All samples were prepared by melt compounding, during which two of the samples (ZnMo and FeHP) displayed erroneous activity during processing and so were eliminated. The remaining 8 FRCs had little effect on PA66 LOI performance with only two samples (AlW and SnW) marginally improving UL94 performance. All samples reduced cone peak heat release rate (PHRR) to levels ranging from 70 % (ZnW) to 53 % (FeAl) compared to the PA66 control. Two FRCs (SnPhPO3 and SnH2PO3) incorporated at a higher level (10 wt%) showed improved performance iv although insufficient for achieving acceptable levels of flame retardancy. Further studies were undertaken to test potential synergism of the FRCs with several phosphorus- and bromine containing flame retardants. Combinations of 3 phosphorus-containing flame retardants (PFRs) with each of the 4 FRCs, FeAl, AlW, SnW and ZnW were studied. A degree of synergy with AlW and SnW combined with aluminium phosphinate (AlPi) was observed and for SnW with a combination of AlPi with melamine polyphosphate (MPP) with respect to UL94 and LOI performance. A moderate reduction in cone PHRR was observed for all FRCs combined with AlPi, and a significant reduction for all with AlPi/MPP. AlW, SnW and ZnW combined with MPP showed moderate improvements in UL94 and LOI and slight reductions in PHRR relative to the MPP control. These results indicate a degree of synergism of several FRCs with PFRs, the greatest effect being observed with the combined vapour and condensed-phase active AlPi/MPP. Two polymeric brominated flame retardants (BrFRs) were selected: brominated polystyrene, (BrPS) and poly(pentabromopolybenzl acrylate (BrPBz), and were compounded with AlW, ZnW and SnW into PA66. AlW displayed significant antagonism with both BrFRs while SnW and ZnW both showed promising improvements in terms of UL94 and LOI performance and significant reductions in cone-derived PHRR values. These results were replicated at various differing Sn:Br and Zn: Br molar ratios. Mechanisms of action of AlW, SnW and ZnW were studied with both PFRs and BrFRs using TGAFTIR and analysis of cone-derived chars. Based on the detailed analysis, the inherent action of these tungstates alone was proposed to be condensed phase, Lewis-acid catalysed cross-linking of PA66), thereby promoting the formation of char, whereas any vapour phase activity for the FRCs such as SnPhPO3 and SnH2PO3 could originate from volatilisation of either phosphorus or metal (Sn, Fe, Zn) acting as vapour-phase radical quenching agents. With regards to the specific mechanism of action of the tungstates with other flame retardant elements, in combination with BrFRs, formation of metal halides and oxyhalides are proposed to contribute to condensed-phase char promotion and vapour-phase radical quenching. In combination with PFRs, increased chain cross-linking promotes the formation of greater char, stabilised by the presence of phosphorus groups and metal oxide residues, coupled with vapour phase activity inherent to AlPi. In conclusion, of 180 FRCs synthesised and screened for potential FR behaviour in PA66, the tungstates in particular were observed to possess both some level of flame retardant behaviour as well as function as synergists with selected phosphorus- and bromine-containing flame retardants. A method for screening future FRCs was also developed.
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Dirscherl, Georg. "Solid-phase synthesis of peptide - metal-complex conjugates." kostenfrei, 2007. http://www.opus-bayern.de/uni-regensburg/volltexte/2009/902/.
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Tahiri, Mohamed. "Phtalocyanines de fer(i) et de fer(0) : synthese, structure et reactivite." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13043.
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Synthese et caracterisation d'une serie de complexes monoreduits de phtalocyanine de fer de type (fe pc r::(8))**(-) ou r=och::(3), ch::(3), h, cl et cn. On donne les structures par rx de composes monoanioniques et dianionique fe pc**(-) et fe pc**(2-). Proprietes chimiques de fe pc**(2-). De tels especes peuvent etre des modeles d'intermediaires formes dans la reaction de la phenylhydrazine sur la metmyoglobine ou dans le metabolisme de substrats suicides par cytochrome p450
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Kazlauskienė, Eglė. "Sorption of metal complex dyes onto ion exchanger resins." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120131_092413-89661.
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Metal complex dyes are a problematic group of substances, present in the negatively charged anion form in mixed industrial wastewater that should be removed. Therefore, a complete removal of these hazardous dyes from wastewaters is necessary to prevent them from release into the environment. Adsorption on activated carbon of dyes has been investigated widely. However some disadvantages using activated carbon in practice were observed, e.g. high regeneration costs and production of fines due to the brittle nature. Since their adsorption capacities, mechanical strength, and other properties need further improvement for wider application, the polymeric sorbents are still under development as a potential alternative to activated carbons. The main aim of the present work was to investigate absorption regularity metal complex Lanasyl Navy M-DNL and Acid Blue 249 (copper (II) phthalocyanine) dyes on synthetic ion exchangers under static conditions and evaluate facility of ion exchangers to removal dyes from wastewaters by dynamic conditions. Screening with chromium-complex dye (acid brown NKM, Lanasyn Navy M-DNL) solutions wide range sorbents, according to the physical chemical characteristics of sorbents and established dye removal parameters (sorption capacity, distribution coefficient and sorbent regeneration) has shown that the polyacrylic, gel type, weakly basic anion exchanger Purolite A 847 (A 845); polystyrene, macroporous, strongly basic anion exchanger Purolite A 500 PS... [to full text]Pagrindinis aplinkosauginės politikos bruožas yra taršos metalo dažikliais mažinimas gamybos metu ir efektyvių šalinimo iš nuotekų metodų paieška. Regeneruojami, mechaniškai atsparūs ir nekenksmingi gamtai polimeriniai sorbentai naudojami dažikliams valyti yra pranašesni už plačiai paplitusias aktyvintąsias anglis. Ištyrus polimerinių sorbentų sorbcines ir regeneracines savybes, nustačius palankias darbines sąlygas, sorbentai gali būti pritaikomi nuotekų valymui, o išvalytas vanduo grąžinamas atgal į gamybinius procesus. Tokiu būdu, vandens ištekliai gali būti apsaugoti nuo taršos sunkiaisiais metalais ir organiniais junginiais, sumažinti gamybos kaštai, nes regeneruoti sorbentai naudojami pakartotinai. Šiame darbe tiriama metalo kompleksinių dažiklių Navy M-DNL (1:2 chromo monoazo kompleksas) (Navy) ir Acid Blue 249 (Vario (II) ftalocianino tetrasulforūgšties tetranatrio druska) (CuPc) sorbcijos sintetiniais jonitais dėsningumus statinėmis sąlygomis ir įvertinti jonitų galimybes valyti nuotekas nuo dažiklių dinaminėmis sąlygomis. Geriausiai iš vandeninių tirpalų šalinantys dažiklius sorbentai atrinkti pagal geriausią sorbcinė gebą ir regeneraciją, dažiklio pasiskirstymo tirpale koeficientą yra: silpnai baziniai anijonitai Purolite A 847 (A 845), stipriai bazinis anijonitas Purolite A 500PS, nejoninis makrotinklinis sorbentas Macronet MN 200. Statinėmis sąlygomis nustatyta dažiklių (Navy ir CuPc) sorbcijai palankiausia terpė (pH 2) ir temperatūra atitinkamai dažikliui Navy... [toliau žr. visą tekstą]
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Venter, Gerhard (Gerhard Abraham). "An Ab Initio density functional study of the structure and stability of transition metal ozone complexes." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52650.
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Thesis (MSc)--Stellenbosch University, 2002.ENGLISH ABSTRACT: A thorough search through the literature as well as through the Cambridge Crystallographic Structural Database resulted in no examples of a neutral ozone acting as ligand in a complex with any metal. Ionic compounds containing ozonide as anionic species, however, are well known throughout the literature and not surprisingly the only result for 0₃ and a metal in the CCSD was an ionic rubidium ozonide compound. What follows is a systematic study into the result of placing an ozone ligand within complexing distance of a transition metal (the first transition row from titanium to copper). Due to the novelty of the system, as first approximation four different orientations of the ozone ligand relative to the metal (a metal cation in these calculations) were investigated. It was found that coordination through the terminal oxygens resulted in energy minima for all the metal cations, although not necessarily the absolute energy minimum on the potential energy surface for the specific cation. A further structural study was done by adding carbonyl and hydrogen ligands to the system, according to the 18-electron rule. For these calculations coordination through the terminal oxygens was employed. In both series the dissociation energy was also calculated. The dissociation energies for the M(CO)nHm(0₃) complexes were all positive, indicating that they are theoretically stable structures. The resulting wave functions were then analysed with the help of three techniques: Atoms in Molecules (AIM), Charge Decomposition Analysis (CDA) and Natural Bond Orbital Analysis (NBO). AIM showed that bonds were indeed formed between the ozone ligand and the transition metal and hinted that the bonding model can be interpreted with the Dewar-Chatt-Duncanson (DCD) model of σ-donation and л-back donation. CDA confirmed that this was the case. NBO results proved erroneous due to the largely delocalized electronic structure of the complexes.
AFRIKAANSE OPSOMMING: 'n Deeglike soektog deur die literatuur en die Cambridge Crystallographic Structural Database het geen resultate gelewer van komplekse waarin 'n neutrale osoonligand komplekseer met 'n metaal nie. Ioniese verbindings waarin die osonied as anioon optree, is wel bekend deur die literatuur en die enigste resultaat in die CCSD - vir 'n soektog bevattende osoon en 'n metaal - het 'n rubidiumosonied-verbinding opgelewer. Wat volg is 'n stelselmatige studie om die effek te ondersoek indien 'n osoonligand naby genoeg aan 'n oorgangsmetaal geplaas word om kompleksering te bevoordeel (metale wat gebruik is, is die eerste oorgangsreeks vanaf titanium tot koper). As gevolg van die onbekendheid van die sisteem is vier verskillende oriëntasies van die osoonligand relatied tot die metal ('n metal katioon in die geval) as beginpunt ondersoek. Daar is gevind dat koordinasie deur die terminale suurstowwe van die osoonligand vir al die metal katione lei tot energie minima, alhoewel dié minima nie noodwendig die globale minima op die potensiële energie oppervlaktes van die katione is nie. 'n Verdere studie is gedoen deur karboniel- en waterstofligande tot die sisteem te voeg, gelei deur die 18-elektron reel. Vir hierdie berekeninge is koördinasie deur die terminale suurstowwe gebruik. In beide reeks is dissosiasie-energieë bereken. Die dissosiasie energieë van die M(CO)nHm(0₃) komplekse was deurgaan positief wat aandui dat die komplekse teoreties stabiel is. Die verkrygde golffunksies is hierna analiseer deur middel van drie tegnieke: Atoms in Molecules (AIM), Charge Decomposition Analysis (CDA) en Natural Bond Orbital Analysis (NBO). AIM het getoon dat bindings inderdaad gevorm word tussen die osoonligand en die metal en bet die moontlikheid laat ontstaan dat die bindingsmodel volgens die Dewar-Chatt-Duncason (DCD) model van σ-donasie en л-terugdonasie geïnterpreteer kan word. Hierdie waarneming is bevestig deur CDA. NBO resultate kon nie suksesvol gebruik word nie as gevolg van die hoë graad van electron delokalisasie van die komplekse.
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Nuel, Didier. "Etude de la reactivite de fragments alkylidynes dans des clusters trinucleaires du fer." Toulouse 3, 1986. http://www.theses.fr/1986TOU30206.
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Reactivite des complexes fe::(3)(co)::(9)(cch::(3))(coc::(2)h::(5)) ou fe::(3)(co)::(10)(cch::(3))(h). Les reactions de couplage des groupes alkylidynes avec les algues sont faciles. L'action de co a mis en evidence le couplage reversible dans des conditions douces de 2 fragments alkylidynes. En general, la presence du coordinat hydruro rend les reactions plus complexes
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Habtu, Michael M. "A study of the transport, extraction and co-ordination chemistry of a number of thiourea ligands with a series of transition and post-transition metal ions." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/97374.
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Thesis (MSc)--Stellenbosch University, 2003.ENGLISH ABSTRACT: In this study, a number of mono- and di-substituted acyl(aroyl)thioureas were investigated for potential application as specific carriers (ionophores) for the transport and extraction of Ag(l) from a mixture of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(lI) ions. The experimental arrangement for the transport experiments employed a liquid membrane set up involving a 3-phase system - 2 aqueous phases (source and receiving phase) separated by a chloroform membrane incorporating the ligand. Competitive metal ion transport experiments were conducted using the liquid membrane set up. The aqueous source and receiving phases were analyzed using Atomic Absorption Spectroscopy (AAS) and results were confirmed by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICPOES). The transport results show that the N,N-dialkyl-substituted-N'-acyl(aroyl) (HL) thioureas studied, with the exception of the N,N-di-(2-hydroxyethyl)-N'-benzoylthiourea (HL3 ) and N-piperidyl-N'-4-nitrobenzoylthiourea (HL9 ), were efficient and selective for Ag(I). HL9 was also selective for Ag(l) but not efficient. HL3 was selective for Cu(II). Under the experimental conditions employed, 13% Cu(lI) was transported by HL3 . Among the N,Ndialkyl- N'-aroylthioureas, maximum Ag(l) transport was obtained by using N,N-diethyl-N'-4- chlorobenzoylthiourea (HL5 ) and N,N-di-n-butyl-N'-benzoylthiourea (HL \ Under the experimental conditions employed, the percentages of Ag(l) transported by HL5 and HL 1 were 48% and 42% respectively. The transport selectivity and efficiency of 3,3,3' ,3'-tetraethyl-1 ,1'-isophthaloylbisthiourea (H2L12 ) and N,N-diethyl-N'-camphanoylthiourea (HL13)for Ag(l) were also studied. We were particularly interested, in comparing the Ag(l) transport and extraction efficiency of these ligands with that of the HL and H2L ligands. The experimental results reveal that, of all the ligands we investigated in this study, HL 13 was the most efficient and selective carrier for Ag(l) transport. The interesting result is that, depending on the ligand concentration used, HL 13 transported 71-81% of Ag(I). Competitive two-phase metal ion solvent extraction experiments were also performed under conditions similar to the transport studies. The results show that by varying the ligand concentration in the membrane phase, up to 100% Ag(l) can be selectively and efficiently extracted from the mixture of the seven metal ions. Finally, the N,N-di-(n)-butyl-N'-benzoylthiourea (HL1) ligand and its complex with Ag(l) were synthesized. Single crystals of the complex were grown for X-ray crystallography and the crystal and molecular structure of the complex was determined. The crystal structure showed that Ag(l) is bonded to the deprotonated ligand through the S,O atoms forming interesting cluster [Ag (L - S, 0)] 4 in the solid state. This structure is monoclinic and crystallizes in the space group P21!c with a = 17.805 (4) A, b = 21.759 (4) A, c = 36.438 (7) A, f3= 96.34(3)°, Z = 8 and a final R-factor of 5.4%.
AFRIKAANSE OPSOMMING: In hierdie proefskrif is 'n aantal mono- en di-gesubstitueerde asiel(ariel) tioureums ondersoek vir moontlike gebruik as ionofore (spesifieke draers) vir die transportasie en ekstraksie van Ag(l) vanuit 'n mengsel van Co(ll), Ni(II), Cu(II), Zn(II), Cd(II), Ag(l) en Pb(lI) ione. 'n Drie-fase selsisteem is gebruik vir die transportasie eksperimente, twee waterige fases (bron- en ontvang-fase) wat geskei is met die chloroform membraan fase wat die ligande bevat. Kompeterende metaalioon transportasie eksperimente is uitgevoer met behulp van hierdie vloeistof membraan stelsel. Die twee waterige fases is deur middel van Atoomabsorpsie Spektroskopie (AAS) ge-analiseer en resultate is bevestig met gebruik van Induktief-gekoppelde Plasma-Optiese Emissie Spektroskopie (IGP-OES). Die resultate het getoon dat elkeen van die N,N-dialkiel-gesubstitueerde-N'-asiel(ariel) (HL) tioureums, met uitsondering van N,N-di(2-hidroksie-etiel)-N'-benzieltioureum(HL 3) en Npiperidiel- N'-4-nitrobenzieltioureum(HL9 ), doeltreffend en selektief was vir Ag(l) transportasie. HL9 was selektief vir Ag(I), maar die transportasie waarde was nie hoog nie, dws. dit was nie doeltreffend nie. HL3 was selektief vir Cu(II). Met gebruik van ons eksperimentele kondisies is 13% Cu(lI) getransporteer deur HL 3. Van die N,N-dialkiel-N'- ariel tioureums, is maksimum transportasie van Ag(l) verkry met gebruik van N,N-dietiel- N'-4-chlorobenzieltioureum (HL5) en N,N-di-n-butiel-N'-benzieltioureum (HL1). Met gebruik van ons eksperimentele kondisies was die persentasie transportasie van Ag(l) deur HL5 en HL 1 48% en 42% onderskeidelik. Die selektiwiteit en doeltreffendheid van 3,3,3' ,3'-tetra-etiel-1 ,t-isoftaltelblstioureumtl+L 12) en N,N-di-etiel-N'-kamfonieltioureum (HL13) vir Ag(l) transportasie is ook onderneem. Ons was besonder ge-interesseerd om die Ag(l) transportasie en ekstraksie van hierdie ligande te vergelyk met dié van die HL en H2L tipe ligande. Die eksperimentele resultate het getoon dat van al die ligande wat bestudeer is, HL 13 die doeltreffendste en mees selektiewe ionofoor was. Van besondere, belang was dat, afhangend van die ligand konsentrasie wat gebruik is, HL13 71-81% Ag(l) getransporteer het. Kompeterende twee-fase metaalioon vloeistof-vloeistof ekstraksie eksperimente is ook uitgevoer onder toestande soortgelyk aan dié van die transportasie eksperimente. Die resultate toon dat met varierende ligand konsentrasie, tot soveel as 100% Ag(l) selektief en doeltreffend geëkstrakeer word vanuit 'n mengsel van die sewe metaal ione. N,N-di-n-butiel-N'-benzieltioureum (HL1 ) ligande en die kompleks daarvan met Ag(l) is ook gesintetiseer. Enkel-kristalle van die kompleks is verkry en X-straal kristallografiese analiese is onderneem. Die kristalstruktuur toon hoedat Ag(l) gebind is aan die gedeprotoneerde ligand deur die S en Q atome en toon ook interessante [Ag(L-S,Q)]4 groepe in die vaste toestand. Hierdie struktuur is monoklinies en kristaliseer in die ruimtegroep P21!c met a = 17.805(4) Á, b = 21.759(4)Á, c = 36.438(7)Á, P = 96.34(3t, z = 8 en 'n finale R-faktor van 5.4%.
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Cartwright, P. S. "Synthetic and spectroscopic studies of transition metal complexes." Thesis, Bucks New University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380302.
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Balkus, Kenneth John. "Metal complex faciliated transport and activation of molecular oxygen." Gainesville, FL, 1986. http://www.archive.org/details/metalcomplexfaci00balk.
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Armstrong, Jennifer A. "Preparation and characterisation of complex metal chalcogenides and halides." Thesis, Loughborough University, 2004. https://dspace.lboro.ac.uk/2134/13015.
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Various compounds with host structures based on geomaterials have been prepared using solid state methods (900-1200 0c), low pressure hydrothermal conditions (<220 °C, <1800 psi) or using purpose-built high pressure equipment <800°C, < 5500Opsi). Each material was characterized using various combinations of powder X-ray and neutron diffraction, single crystal X -ray diffraction, IR spectroscopy, Mossbauer spectroscopy and magnetometry. The iron end member, danalite, of the helvite family of minerals with the formula Feg[BeSi04]6S2 has been prepared for the first time. Isovalent substitution of the sulphide anion has allowed both selenide and telluride materials to be prepared. These compounds crystallize with the sodalite structure in the space group P-43n and exhibit an ordered framework constructed from alternating Be04 and Si04 tetrahedra containing a tetrahedral cluster of iron(II) ions around a central chalcogenide. Mossbauer measurements curiously show that, despite an elongated tetrahedral geometry of three oxide and one cha1cogenide around the iron ions, the valence and lattice contribution to the isomer shift oppose each other leading to zero quadrupole moment at room temperature for the sulphide material. Magnetic and polarized neutron experiments show that the interactions within the tetrahedral metal clusters of divalent ions are predominantly antiferromagnetic. In the sulphide, the clusters behave as totally isolated clusters showing no magnetic interaction across the cages. As the distance between the clusters shortens, as in the case of the selenide, threedimensional interactions between the clusters are observed. A systematic study of an extensive series of compounds in the helvite series, (Mn,Fe,Zn,Co)8[BeSi04]6X2;X = S, Se and Te has been carried out. All diffraction data of the compounds have been refmed using the Rietve1d method and very accurate structural parameters obtained. Correlations between parameters such as the beryllium and silicon tilt angles, framework bond angle and bond lengths as well as the IR absorptions have been drawn for the beryllosilicate sodalite frameworks. The theoretical maximum and minimum cell parameters for a sodalite framework, based on ordered Be04 and Si04 tetrahedra, has been determined.Transition metal boracites with the formula M3B7013X; M = Co, Zn, Mn, X = Cl, Br and I have been prepared using a borate flux. Their stoichiometries have been determined using the Mohr method and Rietveld refinement of powder X-ray diffraction data. In contrast to compounds prepared using hydrothermal methods, the halide site is not heavily substituted by hydroxide. A temperature dependant study of Mg3B7013CIo.78(OH)o.22 is also presented. Magnetic measurements have confirmed dual weak ferromagnetic and antiferromagnetic properties in the iodide materials A series of LnSF and Ln2AF4S2 materials have been synthesized using high temperature sealed tube methods. The missing member of the LnSF series, DySF, has been prepared for the first time. Precise structural data on the LnAF4S2 compounds where Ln = La, Ce, Dy and Er have been gleaned from the Rietveld refinement of powder diffraction data. . In contrast to previous studies, the lanthanide has been shown as preferentially distributed over the two LnlCa sites and the fluoride displaced from a special site to allow pseudo seven coordination for the smaller lanthanides. High-pressure methods have failed to produce the calciurnlgermanium based zeolites such as gismondine or the unusual mineral, bemalite. A new complex phosphate of the formula NaMllf;(P207 )2(P301O), containing the triphosphate unit, has been prepared at high pressure and the structure determined using single crystal methods. Using low pressure hydothermal methods, the full series of lanthanide hydroxide Ln(OH)3 have been prepared. Structure refinement has shown a contraction in the Ln-O bond distance as the series is transversed.
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Sharma, Uma Devi. "Mechanistic studies on transition metal complex catalysed homogeneous hydrogenation." Thesis, University of Oxford, 1996. http://ora.ox.ac.uk/objects/uuid:946e1f34-d03a-4d67-8aa9-37a0794985cf.
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The development of systems capable of catalysing the reduction of unsaturated bonds with very high selectivities is one of the greatest successes of asymmetric catalysis. The mechanism by which rhodium complexes catalyse alkene hydrogenation has been effectively established through a combination of kinetic studies and isolation and characterisation of the intermediates in solution. It was hoped to elucidate the corresponding ruthenium catalysed mechanism using similar techniques. Following the synthesis of a selection of ruthenium catalysts, their activity towards the reduction of a selection of dehydroamino acid derivatives at ambient temperature and pressure was investigated. Having successfully tested out the activity of these catalysts, NMR studies were initiated in order to observe and characterise intermediates in the catalytic cycle. Considerable effort was put into the NMR studies, the systems were looked at under both argon and hydrogen, but although some substrate containing species were observed, it was found to be effectively impossible to break into the catalytic cycle and observe intermediate species using NMR techniques. Electrospray mass spectrometry investigations yielded more successful results, though still no hydrogen containing intermediates were observed. However, it was possible to make a detailed kinetic study of several ruthenium catalyst / substrate systems by looking at the dependence of reaction rate on classic variables such as hydrogen pressure, catalyst concentration and substrate concentration. The combined results of electrospray experiments, kinetic analyses and kinetic modelling using computer packages enabled a possible mechanistic pathway to be proposed.
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Millington, Emma Louise. "Complex pyrrolidines via metal catalysed 1,3-dipolar cycloaddition reactions." Thesis, University of Leeds, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400169.
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Knee, Christopher Sebastian. "Synthesis, structure and magnetic properties of complex metal oxides." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299519.
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Crooks, Richard James. "The synthesis and characterisation of complex metal oxide materials." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241900.
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Jund, Rodolphe. "Electrochimie de clusters mixtes tetrametalliques." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13175.
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Eskhult, Jonas. "Electrochemical Deposition of Nanostructured Metal/Metal-Oxide Coatings." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8186.
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Ghebregziabiher, Berhe Haile. "Synthesis of chiral thiourea ligands and their transition metal complexes." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53610.
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Thesis (MSc)--Stellenbosch University, 2003.ENGLISH ABSTRACT: Modification of chitosan with benzoylisothiocyanate was attempted, however due to solvent problem the study was left incomplete till appropriate solvent is designed. N,N-diethyl-N -camphanoylthiourea (HL8), N-piperidyl-N '-camphanoylthiourea (HL9), N-pyrrolidyl-N -camphanoylthiourea (HL10) and N,N-diethyl-N -adamantylcarbonyl thiourea (HL11)have been synthesised and characterised for the first time. Two of these ligands HL8 and HL11, were used to form a number of transition metal complexes, namely H30+{fae-[Co(L8-S,Obn, cis-[Ni(L8-S,0)2], trans-[Cu(L8-S,0)2], translcis-[Zn(L 8_S,0)2], translcis-[Pt(L 8_S,0)2], Ag2[(HL8-S)(L-J.1-S,O)]2, translcis- [Ni(L11-S,O)2]and translcis-[Cu(L11_S,O)2]. The new products are fully characterised by means of MS, IR spectroscopy, NMR spectroscopy, elemental (C, H, Nand S) analysis and melting point determinations. The H30+{fae-[Co(L8-S,Obn, cis-[Ni(L8- S,O)2], trans-[Cu(L8-S,O)2] and Ag2[(HL8-S)(L-J.1-S,O)]2 are also characterised by Xray diffraction analysis. The structure of the new chiral N,N-dialkyl-N' -camphanoylthiourea ligand (HL8) has a significant effect on its coordination chemistry with transition metal ions. This ligand forms H30+ {fae-[Co(L8-S,Obn, cis-[Ni(L8-S,0)2], trans-[Cu(L-S,O)2] and Ag2[(HL8- S)(L8-J.1-S,O)]2 complexes with the Co(II), Ni(II), Cu(II) and Ag(I) metal ions respectively. The spectroscopic and X-ray diffraction results of these complexes indicate a bidentate mode of coordination of the ligand (with its Sand °donor atoms) to the Co(II), Ni(II) and Cu(II) metal ions. The reaction of this ligand with silver(I) however affords the formation of a binuclear silver(I) complex exhibiting monodentate and bidentate modes of coordination within the same complex. The exclusive formation of trans-[Cu(L8-S,0)2] is a new phenomenon for the HL type thiourea ligands with Sand °donor atoms. Up to this point a maximum of 15 % trans-isomer has been reported in ltterature." All the transition metal complexes made with HL8and HL11are air stable in both the liquid and solid states except the H30+{fae-[Co(L 8-S,Ob]} Interestingly the deep green fae- H30+{fae-[Co(L8-S,Obn complex is air sensitive and the Co(II) oxidizes to Co(III) in the complex by atmospheric O2. The oxidation of Co(II) to Co(III) in the complex is confirmed by 1Hand 13CNMR spectra as well as by UV-Visible spectra of the complex. The NMR spectra of the complexes indicated the presence of one isomer in each complex except for the NMR spectra of the platinum complex of the HL8 ligand. The presence of the minor trans-[Pt(L8-S,Q)21 isomer in combination with the major cis-[Pt(L8-S,Q)21 isomer in the platinum complex was indicated by the 1H, 13Cand 195ptNMR spectra of the complex.
AFRIKAANSE OPSOMMING: Pogings om chitosan met benzoylisothiocyanate te modifiseer is onvoltooid gelaat weens die gebrek aan'n geskikte oplosmiddel. N,N-diethyl-N -carnphanoylthiourea (HL8), N-piperidyl-N -camphanoylthiourea (HL9), N-pyrrolidyl-N -camphanoylthlourea (HL10) en N,N-diethyl-N -adamantylcarbonyl thiourea (HL11) is vir die eerste keer gesintetiseer en gekarakteriseer. Twee van die ligande, HL8 en HL11, is gebruik om verskeie oorgangsmetaalkomplekse te berei, nl. H30+{fac-[Co(L8-S,Ohn, cis-[Ni(L8-S,0)2], trans-[Cu(L8-S,0)2], trans/cis-[Zn(L8 - S,0)2], trans/cis-[Pt(L8-S,0)2], Ag2[(HLB-S)(L-jl-S,0)]2, trans/cis-[Ni(L11-S,0)2] en trans/cis-[Cu(L11_S,0)2]. Die nuwe produkte is volledig gekarakteriseer deur middel van MS, IR spektroskopie, KMR spektrometrie, elemente (C, H, N en S) analise en smeltpuntbepaling. Die komplekse H30+{fao-[Co(L8-S,0)3n, cis-[Ni(L8-S,0)2], trans- [Cu(L8-S,0)2] en Ag2[(HLB-S)(L-jl-S,0)]2 is ook deur middel van X-straaldiffraksieanalise gekarakteriseer. Die struktuur van die nuwe chirale N,N-dialkyl-N'-camphanoylthiourea ligand (HL8) het In beduidende invloed op die koordinasie van hierdie ligand met oorgangsmetaalione. Die ligand vorm H30+{fac-[Co(L8-S,Ohn, cis-[Ni(L8-S,0)2], trans-[Cu(L-S,0)2] en Ag2[(HL8-S)(L8-Il-S,0)]2 komplekse met Co(ll)-, Ni(II)-, Cu(II)- en Ag(I)-ione respektiewelik. Spektroskopiese en X-straaldiffraksie-analise van die komplekse toon dat die ligande op 'n bidentate wyse d.m.v. die S- en O-donoratome met Co(II), Ni(lI) en Cu(lI) koordineer. Die reaksie van hierdie ligand met Ag(I)-ione lei egter tot die vorming van 'n dikernige silwer(I)-kompleks waarin die ligande monodentaat (S) en bidentaat (S en 0) aan die metaal gebind is. Die vorming van uitsluitlik die trans-[Cu(L8-S,0)2] in die reaksie van HL8 met Cu(lI) is 'n besondere fenomeen in die chemie van hierdie tipe ligande; in die literatuur word melding gemaak van slegs een ander trans-kompleks met hierdie ligande, en dan wel met 'n maksimum opbrengs van 15%.29 Alle oorgangsmetaalkomplekse met HLB en HL11 is stabiel indien blootgestel aan lug, ongeag of die verbindings opgelos word of in die vastetoestand verkeer, behalwe H30+{fao-[Co(L8-S,Ohn. Die diep-groen gekleurde H30+{fao-[Co(L8-S,Ohn)3]} kompleks is lugsensitief; Co(lI) word deur lugsuurstof na Co(lIl) ge-oksideer. Die oksidasie in die kompleks kan deur middel van 1H en 13CKMR spektrometrie sowel as UV-sigbare spektrofotometrie bevestig word. Die KMR spektra van alle komplekse dui op die teenwoordigheid van slegs een isomeer in oplossing, behalwe in die geval van die platinum(lI) kompleks met HL8. Die teenwoordigheid van lae konsentrasies trans-[Pt(L8-S,0)2] isomeer tesame met veel hoër konsentrasies van die cis-[Pt(L8 -S,O)2] isomeer word deur 1H, 13Cen 195ptKMR spektroskopie aangedui.
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Holm, Aaron Patrick. "Bulk and element-specific studies of some complex transiton-metal [i.e. transition-metal] Zintl phases /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Fraser, S. G. "Organotransition-metal complexes of molybdenum (II) and tungsten (II)." Thesis, Bangor University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380252.
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Sinha, Pankaj. "Phosphorescent Emissions of Coinage Metal-Phosphine Complexes: Theory and Photophysics." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12200/.
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The major topics discussed are all relevant to the bright phosphorescent emissions of coinage metal complexes (Cu(I), Ag(I) and Au(I)) with an explanation of the theoretical background, computational results and ongoing work on the application in materials and optoelectronic devices. Density functional computations have been performed on the majority of the discussed complexes and determined that the most significant distortion that occurs in Au(I)-phosphine complexes is a near and beyond a T-shape within the P-Au-P angle when the complexes are photoexcited to the lowest phosphorescent excited state. The large distortion is experimentally qualified with the large Stokes' shift that occurs between the excitation and emission spectra and can be as large as 18 000 cm-1 for the neutral Au(I) complexes. The excited state distortion has been thoroughly investigated and it is determined that not only is it pertinent to the efficient luminescence but also for the tunability in the emission. The factors that affect tunability have been determined to be electronics, sterics, rigidity of solution and temperature. The luminescent shifts determined from varying these parameters have been described systematically and have revealed emission colors that span the entire visible spectrum. These astounding features that have been discovered within studies of coinage metal phosphorescent complexes are an asset to applications ranging from materials development to electronics.
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Gazzaz, Hanna Asaad. "Kinetics of metal ion complex formation in self-assembly systems." Thesis, University of East Anglia, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365019.
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Silva, Bermudez Phaedra Suriel. "Adsorption of complex organic molecules on metal single crystal surfaces." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426136.
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Wang, Qianlong. "Synthesis and characterisation of new transition metal complex anion phases." Thesis, University of Bath, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.629666.
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A range of inorganic materials, with structures based on transition metal centred polyhedra linked through simple or polyatomic anions, has been synthesised and fully characterised. These materials were prepared using a variety of synthetic methods, including the direct high temperature, solid state reactions, and hydrothermal techniques in fluoride rich media. The materials produced were structurally characterised by powder (PXD) and single crystal (SXD) X-ray diffraction techniques with further analysis via infrared and UV/visible/near-infrared spectroscopies, thermogravimetric analysis and scanning electron microscopy. Copper (II) phosphates and related materials have potential applications derived from their near-infrared (NIR) radiation absorbing properties. A range of complex copper phosphate phases in the Cu-P-O or A-Cu-P-O systems, where A is a Group 1 or 2 element, has been synthesised and characterised. The intensity and positions of absorptions in the NIR region found for these materials and derived from d-d transitions on copper, are dependent upon the copper ion coordination geometry and the ligand field produced by the surrounding anions. K2CuP2O7 and the phases A3Cu3(PO4)3 (A = Sr, Ca) were all found to absorb strongly in the NIR region. The NIR absorbance spectrum could be modified further by introducing fluoride into the Cu(II) ligand environment and Cu2PO4F was shown to have a very strong, broad NIR absorption spectrum.
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Chieregato, Alessandro. "Glycerol oxidehydration to acrylic acid on complex mixed-metal oxides." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/49558.
Full textAbstract:
[EN] The project of this Ph.D. thesis is based on a co-supervised collaboration between Università di Bologna, ALMA MATER STUDIORUM (Italy) and Instituto de Tecnología Química, Universitat Politècnica de València ITQ-UPV (Spain).
This Ph.D. thesis is about the synthesis, characterization and catalytic testing of complex mixed-oxide catalysts mainly related to the family of Hexagonal Tungsten Bronzes (HTBs). These materials have been little explored as catalysts, although they have a great potential as multifunctional materials. Their peculiar acid properties can be coupled to other functionalities (e.g. redox sites) by isomorphous substitution of tungsten atoms with other transition metals such as vanadium, niobium and molybdenum.
In this PhD thesis, it was demonstrated how it is possible to prepare substituted-HTBs by hydrothermal synthesis; these mixed-oxide were fully characterize by a number of physicochemical techniques such as XPS, HR-TEM, XAS etc. They were also used as catalysts for the one-pot glycerol oxidehydration to acrylic acid; this reaction might represent a viable chemical route to solve the important issue related to the co-production of glycerin along the biodiesel production chain. Acrylic acid yields as high as 51% were obtained and important structure-reactivity correlations were proved to govern the catalytic performance; only fine tuning of acid and redox properties as well as the in-framework presence of vanadium are fundamental to achieve noteworthy yields into the acid monomer.
The overall results reported herein might represent an important contribution for future applications of HTBs in catalysis as well as a general guideline for a multifaceted approach for their physicochemical characterization.[ES] El proyecto de esta tesis doctoral está basado en un convenio de cotutela firmado por la Università di Bologna, ALMA MATER STUDIORUM (Italia) y el Instituto de Tecnología Química, Universitat Politècnica de València ITQ-UPV (España). La presente tesis doctoral muestra el estudio sobre la síntesis, caracterización y ensayos catalíticos de materiales complejos a base de óxidos mixtos relacionados con la familia de los bronces de tungsteno hexagonales. Estos materiales han sido utilizados minoritariamente como catalizadores, aunque tienen un potencial importante come materiales multifuncionales. Sus peculiares propiedades acidas pueden ser acopladas con otras características (por ejemplo, sitios oxido-reductivos) a través de la substitución isomórfica de átomos de tungsteno con otros metales de transición como vanadio, niobio y molibdeno. En esta tesis doctoral se ha demostrado como sea posible preparar bronces de tungsteno hexagonales substituidos a través de síntesis hidrotermal; estos óxidos mixtos fueron caracterizados por completo empleando numerosas técnicas de caracterización quimico-fisicas como XPS, HR-TEM, XAS etc. Fueron también utilizados como catalizadores para la síntesis directa de acido acrílico de glicerol; esta es una reacción que puede representar una solución viable para el problema relacionado con la coproducción de glicerina a lo largo de la cadena productiva del biodiesel. Rendimientos en acido acrílico hasta el 51% fueron obtenidos y importantes relaciones entre las estructuras y la actividad catalítica fueron demostradas ser determinantes para el proceso catalítico; solo la afinación de las propiedades acidas y redox tanto como la presencia en-red de vanadio son esenciales para conseguir rendimientos relevantes en el monómero acido. En general, los resultados presentados en esta tesis doctoral pueden ser una contribución relevante para futuras aplicaciones de los bronces de tungsteno hexagonales en catálisis y también como una guía general para un completa caracterización quimico-fisica de estos oxidos.
[CAT] Esta tesi doctoral està basada en un conveni de cotutela signat per la Università di Bologna, ALMA MATER STUDIORUM (Italia) i el Institut de Tecnologia Química , Universitat Politècnica de València ITQ-UPV(Espanya). La present tesi doctoral estudia la síntesis, caracterització i assajos catalítics de òxids mixtes relacionats amb la família dels bronzes de tungstèn hexagonals. Aquestos materials presenten un gran potencial com materials multi funcionals, encara que no han sigut molt emprats com catalitzadors. Les propietats àcides particulars de aquestos materials poden ser potenciades amb altres característiques (per exemple, llocs redox) mitjançant la substitució isomòrfica d'àtoms de tungstèn amb altres metalls de transició com vanadi, niobi i molibdè. En aquesta tesi doctoral es demostra com es possible sintetitzar bronzes de tungstèn hexagonals substituïts a partir de síntesis hidrotermal. Aquestos òxids mixtes han segut caracteritzats emprant diverses tècniques de caracterització físico-químiques com XPS, HR-TEM, XAS, etc... Per altra part, s'han utilitzat com catalitzadors per a la síntesis directa de àcid acrílic a partir de glicerol, aquesta reacció pot representar una solució viable per al problema relacionat amb la coproducció de glicerina al llarg de la cadena productiva de biodiesel. S'han obtingut rendiments a àcid acrílic del 51%. A més, s'han observat importants relacions entre les estructures i la activitat catalítica, les quals han sigut determinants per al procés catalític. El ajust de les propietats àcides i redox i la presència en red de vanadi són essencials per a obtindre rendiments rellevants en el monòmer àcid. En general, el resultats presentats en aquesta tesi doctoral poden ser una contribució rellevant per a futures aplicacions del bronzes de tungstèn hexagonal en catàlisis i també com una guia general per a una completa caracterització físico-química d'aquestos òxids.
Chieregato, A. (2015). Glycerol oxidehydration to acrylic acid on complex mixed-metal oxides [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/49558
TESIS
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Liu, Yurong. "Synthesis, characterization and applications of bottom-up metal complex nanosheets." HKBU Institutional Repository, 2018. https://repository.hkbu.edu.hk/etd_oa/542.
Full textAbstract:
At the beginning, a brief overview of two-dimensional materials as well as an introduction of the organic metal complex nanosheets was presented in chapter 1. In this section, the attention was mainly focused on the concept of the 2D nanomaterial, including the design strategies, the categories, the synthetic approaches and the characterization methods. Also, the materials used as electrodes of batteries for energy storage were generally introduced. Those electroactive materials were classified according to their different functional mechanism. The opportunity and challenge of this kind of electroactive materials were then demonstrated. At last, the current development of the 2D materials as electrodes, including the typical structures and the superiority, was indicated.;A brand-new symmetric four-way terpyridine derivative (1,2,4,5-tetrakis(4-(2,2':6',2"-terpyridyl)phenyl)benzene) (L7) was then designed and coordinated with Co(II) ion to assemble a novel bottom-up multilayer nanosheet 7-Co in chapter 4. The generated nanosheet featured moderate mechanical strength and insolubility in both aqueous solution and organic solvent, which can facilitate the purification and collection of the product. By taking the advantages of the reversible and robust redox activity of Co2+/Co3+, a dual-ion battery cathode was achieved by employing the 7-Co and thus it reveals the possibility of this kind of metal organic complex nanosheet to be utilized in a battery.;1.7\xFinally, the findings, analysis results and future work were concluded in chapter 6. And the experimental details were described in chapter 7
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Kawakami, Hiroyoshi. "Facilitated transport of gaseous molecules through macromolecule metal complex membranes /." Electronic version of summary, 1991. http://www.wul.waseda.ac.jp/gakui/gaiyo/1667.pdf.
Full text
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Chieregato, Alessandro <1987>. "Glycerol oxidehydration to acrylic acid on complex mixed-metal oxides." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6850/1/Chieregato_Alessandro_Tesi.pdf.
Full textAbstract:
The project of this Ph.D. thesis is based on a co-supervised collaboration between Università di Bologna, ALMA MATER STUDIORUM (Italy) and Instituto de Tecnología Química, Universitat Politècnica de València ITQ-UPV (Spain).
This Ph.D. thesis is about the synthesis, characterization and catalytic testing of complex mixed-oxide catalysts mainly related to the family of Hexagonal Tungsten Bronzes (HTBs). These materials have been little explored as catalysts, although they have a great potential as multifunctional materials. Their peculiar acid properties can be coupled to other functionalities (e.g. redox sites) by isomorphous substitution of tungsten atoms with other transition metals such as vanadium, niobium and molybdenum.
In this PhD thesis, it was demonstrated how it is possible to prepare substituted-HTBs by hydrothermal synthesis; these mixed-oxide were fully characterize by a number of physicochemical techniques such as XPS, HR-TEM, XAS etc. They were also used as catalysts for the one-pot glycerol oxidehydration to acrylic acid; this reaction might represent a viable chemical route to solve the important issue related to the co-production of glycerin along the biodiesel production chain. Acrylic acid yields as high as 51% were obtained and important structure-reactivity correlations were proved to govern the catalytic performance; only fine tuning of acid and redox properties as well as the in-framework presence of vanadium are fundamental to achieve noteworthy yields into the acid monomer.
The overall results reported herein might represent an important contribution for future applications of HTBs in catalysis as well as a general guideline for a multifaceted approach for their physicochemical characterization.
41
Chieregato, Alessandro <1987>. "Glycerol oxidehydration to acrylic acid on complex mixed-metal oxides." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6850/.
Full textAbstract:
The project of this Ph.D. thesis is based on a co-supervised collaboration between Università di Bologna, ALMA MATER STUDIORUM (Italy) and Instituto de Tecnología Química, Universitat Politècnica de València ITQ-UPV (Spain).
This Ph.D. thesis is about the synthesis, characterization and catalytic testing of complex mixed-oxide catalysts mainly related to the family of Hexagonal Tungsten Bronzes (HTBs). These materials have been little explored as catalysts, although they have a great potential as multifunctional materials. Their peculiar acid properties can be coupled to other functionalities (e.g. redox sites) by isomorphous substitution of tungsten atoms with other transition metals such as vanadium, niobium and molybdenum.
In this PhD thesis, it was demonstrated how it is possible to prepare substituted-HTBs by hydrothermal synthesis; these mixed-oxide were fully characterize by a number of physicochemical techniques such as XPS, HR-TEM, XAS etc. They were also used as catalysts for the one-pot glycerol oxidehydration to acrylic acid; this reaction might represent a viable chemical route to solve the important issue related to the co-production of glycerin along the biodiesel production chain. Acrylic acid yields as high as 51% were obtained and important structure-reactivity correlations were proved to govern the catalytic performance; only fine tuning of acid and redox properties as well as the in-framework presence of vanadium are fundamental to achieve noteworthy yields into the acid monomer.
The overall results reported herein might represent an important contribution for future applications of HTBs in catalysis as well as a general guideline for a multifaceted approach for their physicochemical characterization.
42
Lahoud, Marcelo Galindo [UNESP]. "Síntese e investigação da potencialidade de aplicação como material molecular de espécies discretas e Metal Organic Frameworks (MOFs) baseados em íons terras raras." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/143479.
Full textAbstract:
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Este trabalho é dividido em duas partes, na primeira parte foi caracterizado o complexo [Ln(keto)3(H2O)] (Ln = Gd, Eu) por espectroscopia vibracional no infravermelho, analise elementar e otimização da geometria por método DFT. Mas o foco central foram os estudos das propriedades luminescente no intervalo de 12 – 300 K. O espectro de emissão do [Eu(keto)3(H2O)] revela uma forte dependência com a temperatura, bem ilustrada pelo não usual deslocamento amplo para o azul de (17 cm1) da transição 5D07F0 quando a temperatura é elevada de 12 a 300 K. A diferença aritmética entre os espectros de absorção do [Eu(keto)3(H2O)] com o do [Gd(keto)3(H2O)] indicou a presença de uma banda de transferência de carga do ligante para o metal (LMCT) (320-370 nm). A partir da fosforescência do [Gd(keto)3(H2O)] a energia dos estados de tripleto relacionada ao Keto foi determinada mostrando uma grande sobreposição com os níveis intra-4f6 e um forte acoplamento elétron-fônon. A alta ressonância entre o nível LMCT e estados tripletos e os níveis do Eu3+ leva a uma forte dependência do valor do tempo de vida da 5D0, típico da presença de processos de transferência de energia operativos. A segunda parte desse trabalho compreendeu na síntese, caracterização e estudos das propriedades luminescente e magnéticas de uma MOF inédito de formula [Eu2(Btec)1,5(H2O)]n. A MOF foi sintetizada por via hidrotermal e caracterizado por DRX de monocristal e pó, espectroscopia vibracional no infravermelho, reflectância difusa, analise elementar, analise térmica, microscopia eletrônica de varredura e fisissorção de N2. O composto apresentou boa estabilidade térmica no entanto mostrou-se ter baixa porosidade. A MOF apresentou emissão na região do vermelho com elevado rendimento quântico de emissão, mostrando que o ligante é um bom sensibilizador nesse sistema. As emissões dos íons Eu3+ mostraram-se ser uma sonda espectroscópica, contribuindo na elucidação da estrutura. Foi observado uma dependência térmica em relação à intensidade das transições originárias do nível 7F1, em especial a transição 7F15D1. Além disso, as transições intraconfiguracionais 4f-4f mostram ter uma boa fotoestabilidade. Resultados de susceptibilidade magnética mostram íons Eu3+ magneticamente afastados e portanto os torna uma fraca probe estrutural.
This work is divided into two parts, the first part was characterized the complex [Ln(keto)3(H2O)] (Ln = Gd, Eu) by infrared spectroscopy, elemental analysis and geometry optimization by DFT method. But the central focus was the study of luminescent properties in the 12-300 K interval. The emission spectra of [Eu(keto)3(H2O)] reveal a strong dependence with the temperature, well-illustrated by an unusual large blue-shift (17 cm1) of the 5D07F0 transition as the temperature is raised from 12 to 300 K. The arithmetic difference between the absorption spectrum of [Eu(keto)3(H2O)] with that of [Gd(keto)3(H2O)] pointed out the presence of a ligand-to-metal charge transfer (LMCT) band (320-370 nm). From the [Gd(keto)3(H2O)] phosphorescence the energy of the keto-related triplet states was determined showing a large overlap with the intra-4f 6 levels and a strong electron-phonon coupling. The high-resonance between the LMCT and triplet states and the Eu3+ levels leads to a strong dependence of the 5D0 lifetime value, typical of the presence of operative energy transfer processes. The second part of this work included in the synthesis, characterization and study of luminescence and magnetic properties of a novel MOF formula [Eu2(Btec)1,5(H2O)]n. The MOF was synthesized by way hydrothermal and characterized by XRD of single crystal and powder, infrared spectroscopy, diffuse reflectance, elemental analysis, thermal analysis, scanning electron microscopy and N2 physisorption. Compound demonstrated good thermal stability however proved to have low porosity. MOF showed emission in the red region with a high emission quantum yield, showing that the ligand is a good sensitizer in the system. The emission of Eu3+ ions proved to be a spectroscopic probe, contributing to the elucidation of the structure. A thermal dependence was observed in relation to the intensity of originating 7F1 level transitions, in particular the 7F15D1 transition. Furthermore, the 4f-4f transitions intraconfigurational shown to have a good photostability. Magnetic susceptibility results show Eu3+ ions separated magnetically and thus makes a weak probe structure.
43
Meng, Qingen. "Elastohyrodynamic lubrication in metal-on-metal artificial hip joints with aspherical bearing surfaces and complex structures." Thesis, University of Leeds, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.535667.
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Hughes, Ruth. "Serpentine tolerance in the Mimulus guttatus complex." Thesis, University of Exeter, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286489.
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Simpson, Linda. "Trivalent group 13 metal complexes of N-substituted-3-hydroxy-2-methyl-4-pyridinones." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28885.
Full textAbstract:
The compounds tris(N-ռ-propyl-3-hydroxy-2-methyl-4-pyridinonato) aluminum(III), -gallium(III), and -indium(III) and tris(N-ռ-butyl-3-hydroxy-2-methyl-4-pyridinonato)aluminum(III), -gallium(III), and -indium(III) were synthesized. All six compounds were prepared via the metal template effect. They were characterized by IR, FAB-MS, ¹H NMR, ²⁷Al NMR, and elemental analysis. Three of the six complexes were studied by single-crystal X-ray diffraction. They formed trihydrates, unlike their N-methyl and N-ethyl analogues, which formed dodecahydrates. The ռ-butyl complex Al(C₁₀H₁₄N0₂)₃‧3H₂0 (1) and ռ-propyl complexes Al(C₉H₁₂N0₂)₃‧3H₂0 [2], and Ga(C₉H₁₂N0₂)₃‧3H₂0 {3} were basically isostructural, crystallizing in the space group P3 with the following crystal parameters for 1, [2], and {3}: α= 15.885 (1) ([15.328 (1)], {15.367 (2)}) Å, c = 7.280 (8) ([7.2321 (2)], {7.256 (2)}) Å, Z = 2. The data were refined by using 1280 ([1377], {1802}) reflections with I>3σ(I) to R and Rա values of 0.047 ([0.057], {0.055)) and 0.061 ([0.077], {0.081}), respectively. The complexes exist as the rigidly fac geometries with infinite chains of hydrogen bonds parallel to the c axis.Science, Faculty of
Chemistry, Department of
Graduate
46
Jones, Martin Owen. "The synthesis, substitution and reduction of complex ternary oxides." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335607.
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Fallah, Hengameh. "Reductive Functionalization of 3D Metal-Methyl Complexes and Characterization of a Novel Dinitrogen Dicopper (I) Complex." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984200/.
Full textAbstract:
Reductive functionalization of methyl ligands by 3d metal catalysts and two possible side reactions has been studied. Selective oxidation of methane, which is the primary component of natural gas, to methanol (a more easily transportable liquid) using organometallic catalysis, has become more important due to the abundance of domestic natural gas. In this regard, reductive functionalization (RF) of methyl ligands in [M(diimine)2(CH3)(Cl)] (M: VII (d3) through CuII (d9)) complexes, has been studied computationally using density functional techniques. A SN2 mechanism for the nucleophilic attack of hydroxide on the metal-methyl bond, resulting in the formation of methanol, was studied. Similar highly exergonic pathways with very low energy SN2 barriers were observed for the proposed RF mechanism for all complexes studied. To modulate RF pathways closer to thermoneutral for catalytic purposes, a future challenge, paradoxically, requires finding a way to strengthen the metal-methyl bond. Furthermore, DFT calculations suggest that for 3d metals, ligand properties will be of greater importance than metal identity in isolating suitable catalysts for alkane hydroxylation in which reductive functionalization is used to form the C—O bond. Two possible competitive reactions for RF of metal-methyl complexes were studied to understand the factors that lower the selectivity of C—O bond forming reactions. One of them was deprotonation of the methyl group, which leads to formation of a methylene complex and water. The other side reaction was metal-methyl bond dissociation, which was assessed by calculating the bond dissociation free energies of M3d—CH3 bonds. Deprotonation was found to be competitive kinetically for most of the 1st row transition metal-methyl complexes (except for CrII, MnII and CuII), but less favorable thermodynamically as compared to reductive functionalization for all of the studied 1st row transition metal complexes. Metal-carbon bond dissociation was found to be less favorable than the RF reactions for most 3d transition metal complexes studied. The first dinitrogen dicopper (I) complex has been characterized using computational and experimental methods. Low temperature reaction of the tris(pyrazolyl)borate copper(II) hydroxide {iPr2TpCu}2(µ-OH)2 with triphenylsilane under a dinitrogen atmosphere gives the µ -N2 complex, {iPr2TpCu}2(µ -N2). X-ray crystallography reveals an only slightly activated N2 ligand (N-N: 1.111(6) Å) that bridges between two iPr2TpCuI fragments. While DFT studies of mono- and dinuclear copper dinitrogen complexes suggest a weak µ-backbonding between the d10 CuI centers and the N2 ligand, they reveal a degree of cooperativity in the dinuclear Cu-N2-Cu interaction.
48
Pfrunder, Michael Craig. "Halogen bond mediated crystal engineering of metal complexes." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/71083/1/Michael_Pfrunder_Thesis.pdf.
Full textAbstract:
This project explored the potential for halogen bonds to predictably organise metal-containing molecular building blocks in crystalline materials. A novel method for the halogen bond mediated crystal engineering of metal complexes was discovered, which led to the preparation of new materials with potential applications in molecular switching devices and advanced memory storage systems.
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Labonnette, Daniel. "Etude des especes du vanadium iv en milieu faiblement acide et alcalin : isopolyanions mixtes mo**(vi)-v**(iv), complexes carbonates de v**(iv)." Orléans, 1987. http://www.theses.fr/1987ORLE2009.
Full textAbstract:
L'alcalinisation progressive d'une solution acide de vo**(2+) par une base forte, entraine la formation successive des especes : vooh**(+), (vooh)::(2)**(2+) vo(oh)::(2), v::(4)o::(9)h**(-), v::(4)o::(9)h**(-), v::(4)o::(9)**(2-), vo(oh)::(3)**(-) et des ions polycondenses en milieu fortement basique et tres concentre en v(iv). Quand l'alcalinisation est realisee par hco::(3)**(-) ou co::(3)**(2-), il y a formation de complexes carbonato
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Lugan, Noël. "Clusters du ruthenium a ligands assembleurs : stabilite, reactivite." Toulouse 3, 1987. http://www.theses.fr/1987TOU30156.
Full textAbstract:
Etude de la reactivite d'agregats derives de ru::(3)(co)::(12) stabilises par des coordinats polydentes phosphores et/ou azotes, en vue d'application en catalyse homogene. Les coordinats assembleurs sont appm et diphenylpyridylphosphine. On etudie egalement la reactivite des complexes a coordinats acyle ru::(3)(co)::(9)(c(o) (c::(6)h::(5))) (p(c::(6)h::(5)) (c::(5)h::(4)n))