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Dissertations / Theses on the topic 'Transition metal hydrides – Synthesis'

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Published: 4 June 2021

Last updated: 9 February 2022

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1

Fahlquist, Henrik. "Transition Metal Hydride Complexes and Hydrogenated Gallium Clusters : Synthesis and Structural Properties." Doctoral thesis, Stockholms universitet, Institutionen för material- och miljökemi (MMK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-89760.

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Synthesis and structural characterisation of metal hydrides in two important systems are presented. The first system presented is low valent cobalt and nickel complex hydrides with the compositions BaMg5Co2H10, RbMg5CoNiH10, SrMg2CoH7and Sr4Mg4Co3H19 featuring nickel with oxidation state of 0 and cobalt with oxidation state +I and -I. The second system presented is polyanionic gallium complex hydrides with the compositions RbGaH2, RbxK(1−x)GaH2 (0.5≤x≤1), CsxRb(8−x)Ga5H15 (0≤x≤8) and Cs10Ga9H25 featuring novel hydrogenous polyanionic gallium hydride clusters mimicking common hydrocarbons. The syntheses of the compounds were performed at elevated temperatures and at moderate hydrogen pressures (50-100 bar). The structural investigations were mainly done by X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD). The metal-hydrogen bond was investigated by vibrational spectroscopy using Fourier Transform IR-spectroscopy (FTIR) and Inelastic Neutron Scattering (INS).By subtle changes in the compositions of the hydrides it was possible to induce major changes in band gaps, oxidation states and structures.

At the time for the doctoral defence the following papers were unpublished and had a status as follows: Paper 1: Manuscript; Paper 2: Accepted; Paper 5: Manuscript

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2

Mellows, Heather. "Synthesis and properties of two fold symmetric ruthenium and rhodium dihydrogen-hydride complexes /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/8598.

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3

Riddlestone, Ian Martin. "Synthesis and reactivity of transition metal-group 13 complexes." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:f253a2a5-cc6e-4978-86d9-5f3064dadc1b.

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The synthesis and reactivity of a number of mixed transition metal-aluminium and σ-alane complexes are detailed in this thesis. Chapter III reports on the formation and structural characterisation of N,N'-chelated aluminium dihalide precursors featuring amidinate and guanidinate substituents. These precursors of the type RC(R'N)₂AlX₂ (R = ⁱPr₂N or Ph; R' = Cy or ⁱPr or Dipp; X = hal), readily react with Na[CpFe(CO)₂] via salt elimination to form the corresponding mixed iron-aluminium complexes CpFe(CO)2[(X)Al(NR')2CR] which have been characterised both spectroscopically and by X-ray diffraction. The reactivity of the novel mixed aluminium-iron complexes towards halide abstraction agents has been investigated and a propensity for augmented coordination at the aluminium centre observed. Furthermore, complementary syntheses of the methyl substituted complex CpFe(CO)₂[(Me)Al(NCy)₂CNⁱPr₂] have been developed. This can be achieved either via the reaction between the related chloride complex and MeLi, or from the reaction between ⁱPr₂C(CyN)₂Al(Me)Cl and Na[CpFe(CO)₂]. The research detailed in Chapter IV builds on the previous chapter and is focussed on the use of more sterically demanding substituents at both aluminium and transition metal, as well as more electron rich transition metal fragments. The transition metal anions Na[Cp*Fe(CO)₂] and Na[Cp^SiFe(CO)(PPh₃)] react with the aluminium precursors forming related mixed iron-aluminium complexes which have been structurally characterised. The Dipp₂NacNacAlCl₂ precursor has been shown to undergo reaction with both Na[CpFe(CO)₂] and Na[Cp*Fe(CO)₂]. The halide abstraction chemistry of the latter utilising both Lewis acid and salt metathesis based abstraction approaches has been investigated. The dehydrohalogenation chemistry of the Dipp₂NacNacAlCl₂ precursor was investigated and the ligand activated products of reactions with both alkyl lithium and alkyl potassium reagents characterised. Chapter V reports the extension of salt metathesis for the formation of an Al-H-Mn interaction, and the product has been fully characterised. In addition, the coordination of Al-H bonds from a number of alane precursors to in situ generated 16-electron fragments has allowed the structural characterisation of a number of novel σ-alane complexes. The incorporation of the transition metal fragments [Cp'Mn(CO)₂] and [W(CO)₅] permit comparison to archetypal borane and silane σ-complexes. Quantum chemical calculations suggest that the alane ligand has a binding energy close to that of dihydrogen but significantly less than that of CO, consistent with a predominant σ-donor role of the Al-H bond. The formation and structural characterisation of the κ²-complexes (OC)₄M[κ²-H₂AlDipp₂NacNac] (M = Cr, Mo or W) define an unprecedented binding motif for the alane ligand. In the cases of chromium and molybdenum the κ²-complexes can be prepared either photolytically or via alkene displacement from the corresponding (OC)₄M(cod) reagent. In the case of tungsten the alkene displacement route yields the desired product, but only under more forcing conditions. Spectroscopic characterisation of the related κ¹-complex (OC)₅Cr[κ¹-H₂AlDipp₂NacNac], which readily forms the κ²-complex in solution without photolysis, has enabled the kinetics of chelate ring closure to be investigated. This analysis further characterises the formation of the unprecedented κ²-binding motif for the alane ligand.

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4

Hayward, Michael Andrew. "The synthesis and characterisation of some novel reduced transition metal oxides." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326022.

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5

Oldham, Warren James. "Synthesis and NMR properties of dihydrogen-hydride complexes of rhodium and iridium /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/8505.

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6

Bouilly, Guillaume Jacques. "Synthesis and characterization of transition metal oxides and oxyhydrides using epitaxial thin films deposition." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/200450.

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7

Bai, Guangcai. "New methods for the syntheses of amido, imido, nitrido and dinitrogen metal complexes and organometallic hydrides and oxides." Doctoral thesis, [S.l.] : [s.n.], 2001. http://webdoc.sub.gwdg.de/diss/2002/bai/bai.pdf.

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8

White, James P. "Synthesis and characterization of divalent lanthanide (Ln²[superscript plus] = Sm, Eu, Yb) coordination complexes with boron hydride and transition metal carbonyl anions : the formation of metallic films and metal borides from complex precursors /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487681788254429.

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9

Sivakumar, V. "Influence Of The Bite Angles Of Chelating Diphosphine Ligands In The Chemistry Of Ruthenium Hydride And Dihydrogen Complexes." Thesis, Indian Institute of Science, 2006. http://hdl.handle.net/2005/293.

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The bite angle of a diphosphine ligand plays an important role in determining the reactivity of a transition metal complex. The coordinated dihydrogen on a transition metal center can be activated toward homolysis or heterolysis depending upon the nature of the metal center and the ancillary ligand environment. The present work deals with our investigations on the effect of the bite angle of the chelating diphosphine ligands in the chemistry of certain ruthenium hydride and dihydrogen complexes. Protonation of the ds-[Ru(H)2(dppm)(PPh3)2] (dppm = Ph2PCH2PPh2) using HBF4-Et2O resulted in the dihydrogen/hydride complex trans-(Formula). This species shows dynamic exchange of the H-atom between the dihydrogen and the hydride ligands. The H-atom site exchange was studied by NMR spectroscopy. Attempts to prepare the ruthenium dihydride complexes, cis-[Ru(H)2(dppe)(PPh3)2] (dppe = Ph2PCH2CH2PPh2) and cw-[Ru(H)2(dppp)(PPh3)2] (dppp = Ph2PCH2CH2CH2PPh2) with larger bite-angled diphosphines dppe and dppp were unsuccessful. Earlier work in our group on the effect of trans nitrile ligands in a series of complexes of the type (Formula)howed that the properties of the bound H2 are almost invariant with a change in the R group of the nitrile. hi an effort to compare those results with analogous ruthenium complexes bearing smaller bite-angled diphosphine, dppm, we synthesized and characterized a series of complexes of the type (Formula). We found that the properties of the bound H2 were once again invariant with a change in the R group of the nitrile. In an effort to compare the effect of having two diphosphine ligands of different bite angles with systems containing symmetrical diphosphine ligands reported by our group,3 we synthesized a series of complexes of the type (Formula). These complexes exhibit hybrid properties in comparison to systems with symmetrical diphosphine ligands in terms of spectroscopic features and chemical reactivity. Thus, the bite angle of the diphosphine ligand has a definite influence on the properties of the bound H2 ligand.

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10

Ekström, Jesper. "Transition metal hydrides : biomimetic studies and catalytic applications /." Stockholm : Department of Organic Chemistry, Stockholm University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7187.

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11

Ekström, Jesper. "Transition Metal Hydrides : Biomimetic Studies and Catalytic Applications." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7187.

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In this thesis, studies of the nature of different transition metal-hydride complexes are described. The first part deals with the enantioswitchable behaviour of rhodium complexes derived from amino acids, applied in asymmetric transfer hydrogenation of ketones. We found that the use of amino acid thio amide ligands resulted in the formation of the R-configured product, whereas the use of the corresponding hydroxamic acid- or hydrazide ligands selectively gave the S-alcohol. Structure/activity investigations revealed that the stereochemical outcome of the catalytic reaction depends on the ligand mode of coordination. In the second part, an Fe hydrogenase active site model complex with a labile amine ligand has been synthesized and studied. The aim of this study was to find a complex that efficiently catalyzes the reduction of protons to molecular hydrogen under mild conditions. We found that the amine ligand functions as a mimic of the loosely bound ligand which is part of the active site in the hydrogenase. Further, an Fe hydrogenase active site model complex has been coupled to a photosensitizer with the aim of achieving light induced hydrogen production. The redox properties of the produced complex are such that no electron transfer from the photosensitizer part to the Fe moiety occurs. In the last part of this thesis, the development of a protocol for the transfer hydrogenation of ketones to secondary alcohols without the involvement of transition metal catalysts is described. A variety of ketones were efficiently reduced in 2-propanol using catalytic amounts of alkali alkoxide under microwave irradiation.

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12

Lucas, Alun James. "Nuclear magnetic resonance studies of transition metal hydrides." Thesis, University of Warwick, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282531.

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13

Law, James Kirk. "Investigation in transition metal dihydrogen and dihydride chemistry /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/11582.

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14

Barry, Brian Michael. "Synthesis of transition-metal polyphosphides." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/460.

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This dissertation describes the synthesis of several transition-metal polyphosphides including orthorhombic FePc2, cubic CoP3, cubic NiP2, monoclinic PdP2 and monoclinic CuP2. The investigation of these materials was initiated by the discovery of MPx formation upon reacting a metal halide with yellow P4 in superheated toluene. When these MPx products were annealed at moderate temperatures (350-500 °C), crystalline phosphorus-rich phases were afforded. Upon further investigation, we found that these phases have been primarily synthesized from high-temperature elemental reactions and that low temperature routes to these phase-pure polyphosphides using at least one non-elemental source were non-existent in literature. The absence of low-temperature, "bottom up" routes to these materials encouraged us to investigate our initial findings further. Metal-rich counterparts to the aforementioned polyphosphides have been reported on several occasions and have been successfully produced as nanoparticles via molecular, solvothermal reactions. These reports consistently used an excess of phosphorus in their reactions and still afforded metal-rich products, and often times produced materials with a combination of metal-rich and phosphorus-rich phases. These routes showed the inability to dial in the phosphorus content of the produced MPx phases and did not use balanced stoichiometry to rationalize the chemistry, and rarely identified reaction byproducts. This prompted us to design a synthesis in which discrete amounts of phosphours reagent could be used to target specific phases and in which byproducts could be identified allowing us to propose stoichiometric reactions. In order to determine reaction byproducts, a metal halide and yellow P4 were reacted in together without solvent in sealed ampoules. The clear liquid byproduct was identified as PCl3 or PBr3 and balanced reactions could then be performed In these reactions metal halides and phosphorus (red or yellow) were balanced such that the chloride was ideally removed has PCl3 and any remaining phosphorus was used to form targeted, phase-pure MPx phases. Using this stoichiometry in solid-state reactions, all of the aforementioned polyphosphide phases were synthesized as phase pure products at moderate temperatures (500-700 °C). By pelletizing the metal halide reagents in reactions with yellow P4 or by co-pelletizing the metal halide with red phosphorus, pellet products reminiscent of the reagent pellet could be afforded. After identifying the PCl3 byproduct, the stoichiometry used in solid-state reactions was translated to solvothermal reactions. In these reactions, amorphous MPx products were synthesized from metal halides and yellow P4 in various solvents (superheated toluene, 1-octadecene and hexadecane), and upon annealing (350-500 °C), targeted phase -pure CoP3, NiP2 and CuP2 were produced. Reactions substituting red phosphorus for yellow P4 in hexadecane reactions also yielded the same crystalline phases. Solvothermal reactions were modified by the addition of Lewis-base surfactants which led to lower reaction temperatures and in certain systems afforded nanoparticles (10-30 nm). In these reactions a metal acetylacetonate or halide was complexed with a Lewis base, activating the metal halide or acetylacetonate bond, increasing their solubility and reactivity with yellow P4. The Lewis-base surfactants also acted to stunt particle growth. These systems afforded phase-pure NiP2 and CuP2 nanoparticles for the first time.

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15

Matthews, Kelly E. "Elucidation of the aqueous equilibrium system of IrH₂(PMe₃)₃Cl and periodic trends of the iridium (III) dihydrido tris(trimethylphosphino) series, IrH₂(PMe₃)₃X." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-164037/.

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16

Rizo, Pavel. "Mg/transition-metal nanomaterials for efficient hydrogen storage." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1050/document.

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Nanomatériaux à base de magnésium et de métaux de transition pour un stockage efficace de l'hydrogène. Le magnésium est un élément de choix pour le stockage de l’hydrogène à l’état solide en raison de sa grande abondance dans la croûte terrestre et de ses fortes capacités de sorption massique et volumétrique de l’hydrogène. Cependant, la réaction de sorption souffre d'une cinétique lente et l'hydrure formé est trop stable pour des applications fonctionnant sous conditions ambiantes. Le premier problème peut être résolu en développant des composites associant deux hydrures, MgH2 et TiH2, à l'échelle nanométrique. Ces matériaux sont synthétisés par broyage mécanique sous atmosphère réactive. Cette technique permet la formation des nanocomposites et leur hydrogénation en une seule étape. De plus, ces matériaux peuvent être produits à grande échelle pour les besoins des applications. Les travaux ont été menés en trois parties : i) l’optimisation de la teneur en TiH2 dans le système (1-y)MgH2+yTiH2. Ceci a été accompli en ajustant la teneur en titane (0,0125 ≤ y ≤ 0,3 mole), tout en conservant une bonne cinétique, une réversibilité de l'hydrogène et une durée de vie utile. Les données montrent que la valeur y = 0,025 offre le meilleur compromis pour développer les propriétés les plus adéquates; ii) l'extension à d’autres métaux de transition pour le système 0,95MgH2 + 0,05TMHx (TM: Sc, Y, Ti, Zr, V et Nb), en évaluant la contribution de chaque additif sur la cinétique, sur la réversibilité de l'hydrogène et sur la durée de vie en cyclage; iii) la conception d'un dispositif de cyclage automatique capable de réaliser des centaines de sorption/désorption dans le but de mesurer la durée de vie des hydrures métalliques. Le travail a été effectué à l'aide de nombreuses méthodes expérimentales. Pour la synthèse, le broyage réactif sous atmosphère d'hydrogène a été principalement utilisé. La structure cristalline et la composition chimique des nanomatériaux ont été obtenues à partir de l'analyse par diffraction des rayons X (DRX). La taille et la morphologie des particules ont été déterminées par microscopie électronique à balayage et spectroscopie de rayons X à dispersion d'énergie (SEM / EDS). Les propriétés thermodynamiques, cinétiques et cycliques de la sorption d'hydrogène ont été déterminées par la méthode de Sieverts
Mg/transition-metal nanomaterials for efficient hydrogen storageMagnesium metal is a prominent element for solid-state hydrogen storage due to its large abundance in earth’s crust and its high weight and volumetric hydrogen uptakes. However, hydrogen sorption suffers from sluggish kinetics and the formed hydride is too stable for applications working under ambient conditions. The former issue can be solved by developing composites combining two hydrides, MgH2 and TiH2 at the nanoscale. These materials are synthesized by mechanical milling under reactive atmosphere. By this technique, the formation of nanocomposites and their hydrogenation can be obtained in a single-step. Moreover, these materials can be produced at large scale for application purposes. The work focused on three topics: i) the optimization of the TiH2 content in the (1-y) MgH2+yTiH2 system. This was accomplished by optimizing the titanium content (0.0125≤y≤0.3 mole), while keeping good kinetics, hydrogen reversibility and cycle-life. The data show that y=0.025 is the best compromise to fulfill the most practical properties; ii) the extension to other transition metals for the system 0.95MgH2+0.05TMHx (TM: Sc, Y, Ti, Zr, V and Nb), evaluating the contribution of each additive to kinetics, hydrogen reversibility and cycle-life; iii) the conception of an automatic cycling device able to carry out hundreds of sorption cycles whit the aim of measuring the cycle-life of metal hydrides. The work was done using manifold experimental methods. For synthesis, reactive ball milling under hydrogen atmosphere was primarily used. The crystal structure and the chemical composition of nanomaterials was determined from X-ray diffraction (XRD) analysis. Particle size and morphology were obtained by Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM/EDS). Thermodynamic, kinetic and cycling properties toward hydrogen sorption were determined by the Sieverts method

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17

Williams, Dara Bridget. "Tridentate, dianionic ligands for alkane functionalization with platinum(II) and oxidation of iridium(III) hydrides with dioxygen /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8545.

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18

Mobbs, B. E. "Arene transition metal complexes in synthesis." Thesis, University of Oxford, 1985. http://ora.ox.ac.uk/objects/uuid:4c7030d4-297e-4af8-a622-d5b4963fc0a3.

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This thesis deals with the applications of organopalladium and organochromium chemistry to the functionalisation of the benzopyran ring system, at a variety of oxidation levels. Section I demonstrates the functionalisation of 3-, 6-, and 8-bromochromones via palladium (0) insertion into the C-Br bond. The resultant arylpalladium species are shown to undergo addition to the least substituted end of a variety of olefins including methyl acrylate, acrylonitrile and styrene. Subsequent palladium-hydride elimination leads to overall palladium catalysed vinylation of the chromone and the synthesis of a number of novel compounds. Vinylation occurs regiospecifically at the site of chromone bromination and is shown to allow clean substituent introduction into each of the three sites. The palladium catalysed reaction of 3,6-dibromo-chromone with methyl acrylate leads to vinylation at both the C3 and C6 positions. Carbonylation of the 6-bromochromone in ethanol or butanol leads to the 6-ethyl or 6-butyl esters respectively. The palladium catalysed vinylation of the 6-bromochromone with ethyl vinyl ether leads to a mixture of products from addition of the chromone to either end of the olefin. With p-bromophenol or p-bromo-N,N-dimethylaniline the reaction gives exclusively the acetylated product arising from addition to the more substituted end of the olefin. This change in orientation is rationalised by considering the polarisation of the olefin and the arylpalladium species. Section II demonstrates the functionalisation of chroman and 4-chromanol via coordination to the Cr(CO)₃ moiety. (η⁶-Chroman)Cr(CO)₃ is synthesised and is shown to undergo regiospecific ring deprotonation at C8 under kinetic conditions or regiospecific benzylic deprotonation at C4 under thermodynamic conditions. The resultant anions are quenched with alkyl halides, aldehydes, Eschenmoser's salt and methyl disulphide resulting in selective functionalisation of either site. No mixed products are observed. The uncomplexed arene is shown to be totally unreactive under identical conditions. (η⁶-4-Chromanol)Cr(CO)₃ is synthesised and is shown to undergo regiospecific C8 ring deprotonation by comparison with authentic samples of the C5 and C8 methylated alcohols. Protection of the hydroxyl group as its methyl, t-butyldimethylsilyl or methoxymethyl ethers is found not to alter the regiochemistry of deprotonation. The 4-chromanol t-butyldimethylsilyl and tri-i-propylsilyl ethers are synthesised and coordinated to the metal unit. Cleavage of the silyl ethers is shown to proceed with loss of stereochemistry, indicating C-0 bond cleavage.

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19

Hunter, Rupert Alexander. "Transition metal mediated synthesis of heterocycles." Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402426.

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20

Helleren, Caroline Anne. "A search for bridging-dinitrogen heterobimetallic complexes containing iron and molybdenum or tungsten." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241719.

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21

James, Alan Jay. "Metal thiazenes, bulky phosphines, group 11 acetylides and nickel acenaphthalenes /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3074411.

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22

Guillo, Nathalie Christine Monique Marie. "Aspects of transition metal-mediated organic synthesis." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267885.

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23

Warner, P. "Asymmetric synthesis via transition metal acyl complexes." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355823.

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24

Rees, David Alan. "Synthesis of alkaline earth transition metal sulfides." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311775.

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25

Holden, Catherine. "Transition metal-free arylation and heterocycle synthesis." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/transition-metalfree-arylation-and-heterocycle-synthesis(4ecff18c-6cf9-4dfe-a874-1d83601c94d3).html.

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Arenes are ubiquitous motifs in both naturally occurring and synthetic functional organic molecules. The investigation of metal-free methodology for the installation of these motifs is important for sustainable development and the discovery of new modes of reactivity. Chapter 1. The preparation of halogenated phenoxathin 10,10 dioxides was ascertained to proceed through fluoride-induced decomposition and subsequent recombination of two molecules of the o-trimethylsilyl(aryl) triflate aryne precursors. Chapter 2. A new mild and metal-free methodology for the transition metal-free preparation of 2-amino biaryls using the benzyne intermediate was established. This proceeds via a desulfonative Truce-Smiles rearrangement of an aryl anion in the key bond-forming step. Chapter 3. The electron-poor S-aryl sulfonamides developed in chapter 2 were explored as reagents for metal-free 1,1- and 1,2-carbonamination. Asymmetric catalysis was also investigated for the preparation of enantioenriched alpha,alpha-disubstituted aryl glycine derivatives. Chapter 4. Some organocatalytic methods for the vicarious nucleophilic substitution of hydrogen were investigated to expand the remit of this classical arylation mechanism.

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26

Leech, Matthew Christopher. "Transition metal cyaphides : synthesis, reactivity, and electrochemistry." Thesis, University of Sussex, 2019. http://sro.sussex.ac.uk/id/eprint/82053/.

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27

Black, Cameron. "Synthesis and characterisation of transition metal fluorides." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/9652.

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This thesis reports exploratory studies on the synthesis of new vanadium and copper-containing compounds, with a particular emphasis on preparing new magnetically-active materials with S = ½ spin configurations. Eighteen crystal structures are reported, sixteen of which represent new compounds. These materials were studied for magnetic behaviour where appropriate. The sixteen vanadium-containing compounds were prepared using either the hydrothermal, Solvothermal or ionothermal synthesis methods at temperatures ranging from 60 °C to 200 °C. Inorganic cations and organic moieties were used as templating agents to direct the structures, often targeting potentially frustrated lattices based on triangular motifs by using ‘triangular' templating molecules such as guanidine. Solvent choices, as well as reactant ratios were all varied in order to produce the new oxide, fluoride and oxyfluoride compounds of vanadium. Three families of vanadium compounds were prepared from these methods; a family of 1D vanadium (IV) oxyfluoride ladder compounds of general formula AVOF₃ (A=K⁺, Rb⁺, Cs⁺ or NH₄⁺), and a family of 1D vanadium fluoride chain compounds of general formula A₂VF₅ (A=K⁺ or NH₄⁺). The third family is comprised of three vanadium-containing compounds of varying dimensionality that share guanidine as the common organic moiety. Several miscellaneous compounds of vanadium such as clusters and a new V (IV) layer were synthesized, and are reported. The two copper compounds containing compounds, analogous to the pseudo-kagome compound, Cu₃Bi(SeO₃)₂O₂Br, were prepared via solid-state techniques. A detailed neutron diffraction study was carried out on the two compounds to measure the evolution of the magnetic properties from room temperature down to 2.5 K. Representational analysis was utilised in order to provide a detailed magnetic model of the compounds.

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28

Baxter, John S. "Transition metal mediated annulation reactions." Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324243.

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29

Sobaczynski, Adam [Verfasser], and Rhett [Akademischer Betreuer] Kempe. "Alkane Elimination Reactions between Transition Metal Hydrides and Rare-Earth Alkyls / Adam Sobaczynski. Betreuer: Rhett Kempe." Bayreuth : Universität Bayreuth, 2014. http://d-nb.info/1060010151/34.

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30

Pons, Vincent. "From dihydrogen complexes to polyhydrides /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/11571.

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31

Atkins, Andrew J. "Studies on transition metal macrocyclic complexes." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/11664.

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32

Chan, Lai-fung, and 陳麗鳳. "Synthesis, structures and properties of metal-metal bonded transition metal with organothiolate ligands." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40687703.

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Chan, Lai-fung. "Synthesis, structures and properties of metal-metal bonded transition metal with organothiolate ligands." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40687703.

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34

Lightfoot, P. "Synthesis and characterisation of some transition metal phosphates." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382771.

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Aldous, David W. "The solvothermal synthesis of early transition metal fluorides." Thesis, University of St Andrews, 2008. http://hdl.handle.net/10023/578.

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In this thesis, 60 crystal structures which have been synthesised by the solvothermal method are reported, with 57 of them representing novel materials. The remaining three materials have previously been reported but have been made by a new and milder method of synthesis. Ti, Zr, Hf, V, Nb, Ta and Mo have all been used to make fluoride or oxyfluoride materials at temperatures ranging from 60C to 200C. Both inorganic and organic moieties ("templates") have been used to direct the formation of the (oxy)fluoride materials, usually as an anionic species. These materials have then been studied for their magnetic properties, where relevant. Initially, 10 vanadium-based compounds were made at 100C using a range of templates. Through variations in water content, temperature and cation ratio, a further 19 compounds were synthesised. The inorganic species in these structures ranged from monomers, to dimers, tetramers and chains, to infinite 2D sheets. A family of vanadium compounds has been synthesised, with piperazine as a template, which shows an increase in covalent connectivity through the increase of the reaction temperature, with a decrease in oxidation state as a result. These materials are also interrelated through the use of a "Y" shaped motif in their structural composition. Through a change in cation content a novel trigonal chain compound (related to the structure of CsCrF₄) has been synthesised with piperazine which possibly shows strong geometric frustration. Vanadium oxyfluoride analogues of (VO)₂P₂O₇ have been made, which show interesting magnetic properties with a range of different templates, ranging from alkali metal cations to the bulky protonated template trans 1,2 bis (4-pyridyl) ethene. The best fits to the magnetic susceptibility data are obtained with an antiferromagnetic Heisenberg chain model. Nine molybdenum-based structures have also been synthesised, with five of the structures being made through changes in the temperature and cation ratio of the reactions. An example of this is the formation of tetrameric units with ammonium, through the condensation of monomers as a result of an increase in the reaction temperature. A further 22 structures have also been made with metals, M = Ti, Zr, Hf, Nb and Ta. These structures have a tendency to form isolated polyhedral units under the conditions studied in this work. Several examples of isolated [MF₆][superscript n-] and [MF₇][superscript n-] monomers are reported and also one example of a trans-connected [TiOF₄]²⁻ infinite chain structure.

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Sviridov, Lev A. "Synthesis and Characterization of New Transition - Metal Nitrides." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526120.

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Lawson, Iain M. "Transition metal mediated synthesis of biologically important heterocycles." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427320.

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Clucas, J. A. "Synthesis and structural characterisation of transition metal clusters." Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383429.

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Dossett, David Michael. "The synthesis of novel chiral transition metal complexes." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402060.

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Şahin, Aytaç Eanes Mehtap. "Hydrothermal Synthesis and Characterization of Transition Metal Oxides/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/malzemebilimivemuh/T000435.doc.

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41

Shaw, Graham Andrew. "Solvent mediated synthesis of metal chalcogenides." Thesis, University College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326065.

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42

Rook, John. "Some studies of transition metal chalcogenide fluorides." Thesis, University of Leicester, 1987. http://hdl.handle.net/2381/33876.

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Attempts have been made to synthesise thio-fluoride species of tantalum, osmium and iridium. The reaction of tantalum thiotrichloride and tri- bromide with an excess of anhydrous HF yields [SH3]+ [Ta2F11]-. When anhydrous HF is added to a solution of TaSX3 (X =C1 or Br) in aceto- nitrile an oil is formed which contains =NH and ENH+. The thermal reactions of the hexafluorides of osmium and iridium with zinc and boron sulphides yield the adducts SF4.MF5 (M=Os or Ir). Infra-red and X-ray powder diffraction studies indicate that they have contributions to the bonding from the ionic formulations [SF3]+ [MF6]-. The reaction of MF6 with antimony sulphide in anhydrous HF gives only lower oxidation-state fluorides. The reaction of the alkali metal fluorides with tungsten thiotetra-fluoride in anhydrous HF has yielded the first examples of solids containing [W2S2F9]- and [WSF5]-, viz. M+[W2S2F9]- (M=Li, Na, K, Rb or Cs) and M+[WSF5]- (M=Rb or Cs). Nitrosyl fluoride reacts rapidly with tungsten thiotetrafluoride to yield [NO]+ [WOF5]-, [NO]2+ [WF8]2- and sulphuryl fluoride. However, a low-temperature n.m.r. study has shown that the reaction initially yields [W2S2F9]- and [WSF5]-. Tungsten oxidetetrafluoride reacts with an excess of sulphur tetra-fluoride to give [SF3]+ [W2O2F9]-. X-ray powder diffraction, infra-red and n.m.r. studies have shown that fluorine bridging between [SF3]+ and [W2O2F9]- in the solid state or in solution in sulphur dioxide is minimal. The reaction between tungsten thiotetrafluoride and sulphur tetrafluoride yields only tungsten hexafluoride and sulphur. Xenon difluoride reacts violently with tungsten thiotetrafluoride in the solid state to yield tungsten hexafluoride, xenon and fluorides of sulphur. When the reaction is conducted in sulphuryl chloride fluoride at low-temperature a red-brown solution is formed. This has been shown to consist of tungsten hexafluoride and the radical cation, S8+. by n.m.r. and e.s.r. spectroscopy. The standard enthalpy of formation of tungsten thiotetrafluoride has been determined by hydrolysis in alkaline media.

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Yu, Yongfei. "Synthesis, structure and properties of some chiral-at-metal transition metal organometallics." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0015/NQ42488.pdf.

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Compton, Neville A. "Some aspects of transition metal bismuth chemistry." Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244895.

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45

Verendel, J. Johan. "Transition Metal Catalysis for Selective Synthesis and Sustainable Chemistry." Doctoral thesis, Uppsala universitet, Syntetisk organisk kemi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-182900.

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This thesis discusses the preparation and use of transition-metal catalysts for selective organic chemical reactions. Specifically, two different matters have been studied; the asymmetric hydrogenation of carbon-carbon double bonds using N,P-ligated iridium catalysts and the metal-catalyzed transfer of small molecules from biomass to synthetic intermediates. In the first part of this thesis, chiral N,P-ligands were synthesized and evaluated in iridium catalysts for the asymmetric hydrogenation of non- and weakly functionalized alkenes (Papers I & II). The new catalysts were prepared via chiral-pool strategies and exhibited superior properties for the reduction of certain types of alkenes. In particular, some of the catalysts showed excellent activity and selectivity in the enantioselective reduction of terminal alkenes, and the preparation of a modular catalyst library allowed the asymmetric hydrogenation of a wide range of 1,1-disubstituted alkenes with unprecedented efficiency and enantioselectivity (Paper III). Methods for the selective preparation of chiral hetero- and carbocyclic fragments using iridium-catalyzed asymmetric hydrogenation as an enantiodetermining key step were also developed. A range of elusive chiral building blocks that have applications in pharmaceutical and natural-product chemistry could thus be conveniently prepared (Papers IV & V). The second part of this thesis deals with the catalytic decomposition of polysaccharides into sugar alcohols and the incorporation of their decomposition products into alkene substrates. Iridium-catalyzed dehydrogenative decarbonylation was found to decompose polyols into CO:H2 mixtures that could be used immediately in the ex situ low-pressure hydroformylation of styrene (Paper VI). The net process was thus the hydroformylation of alkenes with biomass-derived synthesis gas.

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Cecchini, Chiara. "Late Transition Metal-Oxo complexes: Synthesis, and Biorelevant Reactivity." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11249/.

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High-valent terminal metal-oxygen adducts are supposed to be potent oxidising intermediates in enzymatic catalyses. In contrast to those from groups 6-8, oxidants that contain late transition metals (Co, Ni, Cu) are poorly understood. Because of their high reactivity, only a few examples of these compounds have been observed. The aim of this project was to investigate the reactivity of high-valent Ni(III) complexes, containing a monodentate oxygen-donor ligands, in hydrogen atom abstraction (HAA) and oxygen atom transfer (OAT) reactions which are typical of biological high-valent metal-oxygen species. Particularly, the Ni(III) complexes were generated in situ, at low temperature, from the oxidation of the Ni(II) species.The nickel complexes studied during this work were supported by tridentate ligands, with a strong σ-donating ability and exceedingly resistant to several common degradation pathways. These complexes vary based on the monodentate group in the fourth coordination position site, which can be neutral or anionic. In particular, we prepared four different Ni(III) complexes [NiIII(pyN2Me2)(OCO2H)] (12), [NiIII(pyN2Me2)(ONO2)] (14), [NiIII(pyN2Me2)(OC(O)CH3)] (18) and [NiIII(pyN2Me2)(OC(O)H)] (25). They feature a bicarbonate (-OCO2H), nitrate (-ONO2), acetate (-OC(O)CH3) and formate (-OC(O)H) group, respectively.HAA and OAT reactions were performed by adding 2,6-di-tert-butylphenol (2,6-DTBP) at -40°C, and triphenylphosphine (PPh3) at -80°C, to the in situ generated Ni(III) complexes, respectively. These reactions were carried out by adding 7 to 500 equivalents of substrate, in order to ensure pseudo-first order conditions. Since, the reactivity of the Ni(III) complex featured by the bicarbonate group has been studied in a previous work, we only investigated that of the species bearing the nitrate, acetate and formate ligand. Finally we compared the value of the reaction rate of all the four species in the HAA and OAT reactions.

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Llaveria, Cros Josep. "Synthesis of sphingoid bases by transition metal-catalyzed reactions." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/32215.

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Les bases esfingoides, aminoalcohols de cadena llarga, sovint es troben enllaçades a un àcid gras formant les anomenades ceramides. Aquestes ceramides constitueixen la part hidrofòbica essencial dels glicolípids, com -GalCer, iGB3 o KRN7000, que es troben a la membrana de les cèl·lules eucariotes i que participen en processos fisiològics importants involucrats en la prevenció de malalties com infeccions virals, infeccions microbianes, càncer, diabetis, malalties de Parkinson i Alzheimer entre d’altres. Dins el marc de la necessitat de desenvolupar noves metodologies de síntesi d’aquestes bases esfingoides, en la present tesi doctoral s’han desenvolupat tres nous mètodes sintètics, sent els mètodes estereoselectius més eficients fins el moment, basats en reaccions catalitzades per metalls de transició.
Glycosphingolipids are commonly found in eukaryotic cell membranes, plasma membranes and some intracellular organelles. They play a critical role in communication as shown promising bioactivities against diverse pathologies. Glycosphingolipids are constituted by a mono- or oligosaccharide moiety link to the ceramide part, which is a sphingoid base link to a fatty acid. Due to its importance, it is necessary to develop new methodologies to synthesize them. In this thesis, we developed three new synthetic methods based on stereoselective processes catalyzed by transition metal reactions.

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Yao, Yiming. "Heliphos and its transition metal complexes, design and synthesis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq21228.pdf.

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Trono, Corazon. "Transition metal catalyzed synthesis of glycoclusters from sugar alkynes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58515.pdf.

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50

Pan, Jiehui. "Transition metal catalyzed cyclization and synthesis of triptolide analogs." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37765966.

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