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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Synthesis, structures and reactions of new cyclometallated dinuclear gold complexes containing the fluorine-substituted ligands.

Mirzadeh, Nedaossadat, s3114476@student.rmit.edu.au January 2008 (has links)
The dinuclear cyclometallated gold(I) complex [Au2(μ-2-C6F4PPh2)2] was prepared in high yield from the reaction of 2-LiC6F4PPh2 with either [AuBr(AsPh3)] or [AuCl(tht)], and from the reaction of 2-Me3SnC6F4PPh2 with [AuCl(tht)]. The digold(I) complex undergoes oxidative addition reactions with halogens to give the metal-metal bonded dihalodigold(II) complexes [Au2IIX2(μ-2-C6F4PPh2)2] (X = Cl, Br, I), which on warming or exposure to light, isomerise to give the heterovalent gold(I)-gold(III) species [XAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuX] containing a four-membered cyclometallated ring on a gold(III) centre. Unlike its protio analogue, [Au2(μ-2-C6F4PPh2)2] did not undergo oxidative addition of methyl iodide or dibenzoyl peroxide. The dihalodigold(II) [Au2IIX2(μ-2-C6F4PPh2)2] and gold(I)-gold(III) compounds [XAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuX] (X = Cl, Br) are further oxidised by halogens to give the digold(III) species [Au2X4(μ-2-C6F4PPh2)2] and [X3Au(μ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuX], respectively. The complexes [Au2X4(μ-2-C6F4PPh2)2] are reduced to the dihalodigold(II) complexes in the presence of one equivalent of zinc powder; further addition of zinc gave the parent digold(I) dimer. Treatment of [Au2IICl2(μ-2-C6F4PPh2)2] and [ClAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuCl] with an excess of silver nitrate, benzoate, acetate, trifluoroacetate or triflate gave the corresponding oxyanion complexes. Slow crystallisation of the di(benzoato)digold(II) complex from dichloromethane and methanol gave the parent digold(I) complex derived by reductive elimination. The di(triflato)digold(II) complex behaved similarly, although in this case the novel gold(I) tetramer [Au4(μ-2-C6F4PPh2)4] was formed together with the dimer. Two closely related gold complexes containing the chelating κ2(C,O) phosphine oxide ligand, 2-C6F4P(O)PPh2, were isolated from the reaction of [ClAu(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuCl] with an excess of silver nitrate. The reaction of [Au2IICl2(μ-2-C6F4PPh2)2] with two equivalents of potassium trifluoroethoxide failed to give the corresponding digold(II) bis(alkoxo) complex; instead, reduction took place to form the digold(I) dimer [Au2(μ-2-C6F4PPh2)2]. Treatment of a solution of the di(benzoato)digold(II) complex with C6F5Li gave the pentafluorophenyl complex [Au2(C6F5)2(μ-2-C6F4PPh2)2] which, when heated in toluene, rearranged to the gold(I)-gold(III) complex [(C6F5)Au(µ-2-C6F4PPh2)(κ2-2-C6F4PPh2)Au(C6F5)], analogous to the behaviour of the dihalodigold(II) complexes. The heterovalent, gold(I)-gold(III) dimethyl compound [Au2I,III(CH3)2(μ-2-C6F4PPh2)2] was obtained from the reaction of the di(benzoato)digold(II) complex with dimethylzinc. This compound is structurally similar to its tetraprotio analogue. The cycloaurated dinuclear gold complexes [Au2(μ-C6H3-n-F-2-PPh2)2] (n = 5, 6) were made similarly to the 2-C6F4PPh2 analogue from the appropriate lithium or tin reagents, though in some cases the dimers were formed in admixture with the corresponding gold(I) tetramers. Like their tetrafluoro analogues, the 6-fluoro complexes [Au2X2(μ-C6H3-6-F-2-PPh2)2] (X = Cl, Br, I) rearrange on heating to give the heterovalent gold(I)-gold(III) species [XAu(µ-C6H3-6-F-2-PPh2)(κ2-C6H3-6-F-2-PPh2)AuX]. Thus, the presence of a fluorine atom in place of hydrogen in the 6-position of the bridging aryl group is sufficient to stop the isomerisation of the digold(II) complexes [Au2X2(μ-2-C6H4PPh2)2] at the gold(I)-gold(III) stage and to prevent subsequent C-C coupling of the aryl groups at the gold(III) centre. In contrast, the dihalodigold(II) complexes containing the 5-fluoro substituted ligand undergo reductive elimination and coupling of the metallated aryl groups to give the digold(I) biphenyldiyl complexes [Au2X2(2,2'-Ph2P-5-FC6H3C6H3-5-F-PPh2)] (X = Cl, Br, I). The described complexes were characterised using 1H NMR, 31P NMR, 19F NMR spectroscopy, elemental analysis, mass spectroscopy, IR spectroscopy, X-ray diffraction and 197Au Mössbauer spectroscopy.
2

Photochemical and Photophysical Properties of Mononuclear and Multinuclear Closed Shell D10 Coinage Metal Complexes and Their Metallo-organometallic Adducts

McDougald, Roy N., Jr. 12 1900 (has links)
This dissertation covers the studies of two major topics: the photochemistry of mononuclear and multinuclear gold(I) complexes and synthetic approaches to tailor photophysical properties of cyclic trinuclear d10 complexes. First a detailed photochemical examination into the photoreactivity of neutral mononuclear and multinuclear gold(I) complexes is discussed, with the aim of gold nanoparticle size and shape control for biomedical and catalysis applications. Next is a comprehensive systematic synthetic approach to tailor the photophysical properties of cyclic trinuclear d10 complexes. This synthetic approach includes an investigation of structure-luminescence relationships between cyclic trinuclear complexes, an examination into their π-acid/π-base reactivity with heavy metal cations and an exploration into the photophysical properties of new heterobimetallic cyclic trinuclear complexes. These photophysical properties inspections are used to screen materials for their employment in molecular electronic devices such as organic light-emitting diodes (OLEDs) and thin film transistors (OTFTs).
3

Development of Hybrid QM/QM Local Correlation Methods for the Study of Metal Sites in Biomolecular Catalysis

Andrejić, Milica 27 March 2015 (has links)
No description available.
4

Chimie de coordination du phosphore aux métaux du groupe 11 : progrès en catalyse de couplage C-N au Cu(I) et nouveaux complexes polyphosphines de l'Au(I) / Phosphorous coordination chemistry to group 11 metals : improvements in C-N cross-coupling catalyzed by Cu(I) and new polyphosphinic complexes of Au(I)

Rampazzi, Vincent 23 June 2014 (has links)
De nos jours et depuis quelques années maintenant, le principe de développement durable encourage les chimistes de tous horizons à développer de nouvelles méthodes de synthèse économiques et écologiques, les ressources naturelles de notre planète ne sont pas illimitées. Parmi les ressources les plus exploitées, nous trouvons le pétrole et le gaz. Outre ces derniers et le gaz, les métaux précieux sont également devenus indispensables.Cette thèse se concentre sur la valorisation de complexes de cuivre et d’or, obtenus à partir de ligands phosphorés synthétisés au sein du laboratoire. Dans un premier temps, nous verrons la mise au point d’une réaction de N-arylation de pyrazoles catalysée par un complexe de cuivre portant un ligand hybride phosphinoalcène. Dans un deuxième temps, les propriétés de coordination de l’or à différentes polyphosphines ferrocéniques seront étudiées. Plusieurs complexes innovants seront mis en évidence et pourront être utilisés dans le cadre de futures études de catalyse, ou de luminescence. / Nowadays, sustainable development encourages chemists to develop new economic and ecologic synthesis, because natural ressources are reducing. Most exploited ressources are gas and petroleum, but precious metals are also essential. This thesis is focusing on the enhancement of gold and copper complexes, obtained in our laboratory from phosphorous-based ligands. In the first part, we will develop a new system for the N-arylation of pyrazoles from a copper complexe coordinated by a new hybrid phosphinoalkene ligand. In the second part, coordination properties of gold to different ferrocenic polyphosphine will be studied. Several new innovative complexes will be isolated, and could be used in future catalytic or luminescent studies.
5

Étude théorique de complexes inorganiques et de clusters métalliques de taille nanométrique : interprétation de leurs structures et de leurs propriétés / Theoretical investigations of inorganic complexes and metallic clusters of nanometric size : rationalization of their structures and properties

Latouche, Camille 30 September 2013 (has links)
Les travaux décrits dans cette thèse ont porté sur l'application de méthodes de la chimie quantique à l'étude de différents types et familles de composés chimiques, à savoir, des clusters encapsulant des anions et des complexes inorganiques de métaux de transition. On s'est particulièrement intéressé à la structure géométrique, la structure électronique et aux relations structures-propriétés optiques de systèmes moléculaires stables et bien caractérisés. / The work reported in this manuscript deals with the applications of quantum chemistry tools on several types and families of chemical compounds, i. e., clusters entrapping anions and transition metals inorganic complexes. We have mainly focused our attention on the geometrical structure, the electronic structure and on the relationship between structure and optical properties of stable molecules which have been synthesized and characterized.
6

Advances in gold-carbon bond formation: mono-, di-, and triaurated organometallics

Heckler, James E. 27 January 2016 (has links)
No description available.

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