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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.
11

Carbon Nanostructures – from Molecules to Functionalised Materials : Fullerene-Ferrocene Oligomers, Graphene Modification and Deposition

Nordlund, Michael January 2017 (has links)
The work described in this thesis concerns development, synthesis and characterisation of new molecular compounds and materials based on the carbon allotropes fullerene (C60) and graphene. A stepwise strategy to a symmetric ferrocene-linked dumbbell of fulleropyrrolidines was developed. The versatility of this approach was demonstrated in the synthesis of a non-symmetric fulleropyrrolidine-ferrocene-tryptophan triad. A new tethered bis-aldehyde, capable of regiospecific bis-pyrrolidination of a C60-fullerene in predominantly trans fashion, was designed, synthesised and reacted with glycine and C60 to yield the desired N-unfunctionalised bis(pyrrolidine)fullerene. A catenane dimer composed of two bis(pyrrolidine)fullerenes was obtained as a minor co-product. From the synthesis of the N-methyl analogue, the catenane dimer could be separated from the monomeric main product and fully characterised by NMR spectroscopy. Working towards organometallic fullerene-based molecular wires, the N-unfunctionalised bis(pyrrolidine)fullerene was coupled to an activated carboxyferrocene-fullerene fragment by amide links to yield a ferrocene-linked fullerene trimer, as indicated by mass spectrometry from reactions carried out at small scale A small library of conjugated diarylacetylene linkers, to be coupled to C60 via metal-mediated hydroarylation, was developed. Selected linker precursors were prepared and characterised, and the hydroarylation has been adapted using simple arylboronic acids. Few-layer graphene was prepared and dip-deposited from suspension onto a piezoelectric polymer substrate. Spontaneous side-selective deposition was observed and, from the perspective of non-covalent interaction, rationalised as being driven by the inbuilt polarization of the polymer. Aiming for selectively edge-oxidized graphene, a number of graphitic materials were treated with a combination of ozone and hydrogen peroxide under sonication. This mild, metal-free procedure led to edge-oxidation and exfoliation with very simple isolation of clean materials indicated by microscopy, spectroscopy, and thermogravimetric analysis.
12

ANION EFFECTS IN HOMOGENOUS PALLADIUM CATALYSIS AND LUMINESCENT PROPERTIES OF COPPER(I) COMPLEXES BEARING A WEAKLY-COORDINATING ANIONIC N-HETEROCYCLIC CARBENE LIGAND

Sabbers, William Anthony January 2021 (has links)
The general theme of this dissertation concerns how the locality of an anionic moiety, be it a weakly coordinating anion or an anionic ligand, affect the spectroscopic and structural properties of organotransition metal complexes. Probing the columbic interactions between traditional and novel weakly coordinating anions with transition metal complexes, enables synthetic chemists to select anions that can improve catalytic transformations, impart stability of reactive intermediates, or develop new mechanistic insights. Additionally, presented herein is the manifestation of a new class of luminescent copper complexes which bear a weakly coordinating anionic N-heterocyclic carbene ligand.Firstly, a qualitative scale of coordinating ability is prepared by pairing traditional anions and weakly-coordinating anions with [Pd(IPr)(C(O)C9H6N)]+. NMR, IR, Computation, %Vbur, and X-ray crystallographic techniques are used to study the solution and solid-state interactions of these salts. During this study, a novel anion, denoted IMP- is prepared where two B(C6F5) groups are bridged by a phenyl imidazole core. Ultimately, it was found that sterics dictate coordinating ability observed by NMR and %Vbur, while IR and computation show the electronic effects of anion coordination. Continuing our understanding of the interplay between cation and anion, anionic Au(I) complexes are synthesized and paired with the same palladium cation in our first investigation. The framework of these Au(I) anions features a weakly coordinating N-heterocyclic carbene ligand that bears a borate moiety of the NHC backbone. Facile dissociation of a dimethyl sulfide ligand with metal alkoxide/phenoxides/thiophenoxides affords sodium or potassium salts. With these anions in hand, ion pairs are isolated in polar solvents and in the solid state. Au anions reside in the outer sphere of the palladium cation; like that of weakly coordinating anions such as BArF4-. Lastly, Luminescent group 11 organometallic complexes featuring N-heterocyclic carbene (NHC) ligands offer a swath of applications; catalytic transformations in organic chemistry to inorganic material uses in light emitting technologies. Conventional complexes are of the type NHC-M-X, where M is Cu, Ag, or Au and X represents anionic ligands that are often prone to hydrolysis. In this dissertation, Cu(I) complexes featuring this N- heterocyclic carbene ligand bearing a weakly coordinating anionic substituent (WCA-NHC) are prepared. (WCA-NHC)-M-L are air and moisture stable and differ from conventional NHC-M-X in that the metal can be supported by 2 datively-bound ligands. Initial computation reveals a change in dipole of (WCA-NHC)-Cu-PR3 charge transfer compared to that of reported NHC-M-X. By exchanging triphenylphosphine for diphenyl-2-pyridyl phosphine, we can change the emission wavelength by about 200 nm. / Chemistry
13

Novel rhodium on carbon catalysts for the oxidation of benzyl alcohol to benzaldehyde: A study of the modification of metal/support interactions by acid pre-treatments

Wilde, C.A., Ryabenkova, Yulia, Firth, I.M., Pratt, L., Railton, J., Bravo-Sanchez, M., Sano, N., Cumpson, P.J., Coates, Philip D., Liu, X., Conte, M. 13 November 2018 (has links)
Yes / Rhodium nanoparticles or rhodium organometallic complexes are mainly used in catalysis for reduction or hydroformylation reactions. In this work instead, we explored the capabilities of Rh nanoparticles as an oxidation catalyst, applied to the oxidation of benzyl alcohol to benzaldehyde under very mild conditions (100 °C, and atmospheric pressure) as a model reaction. Here we report the preparation of novel Rh/C catalysts by using an impregnation protocol, with particular emphasis on the pre-treatment of the carbon supports by using HNO3 and HCl, as well as the characterization of these materials by using an array of methods involving TEM, XPS and XRPD. Our preparation method led to a wide Rh particle size distribution ranging from 20 to 100 nm, and we estimate an upper limit diameter of Rh nanoparticles for their activity towards benzyl alcohol oxidation to be ca. 30 nm. Furthermore, a HNO3 pre-treatment of the activated carbon support was able to induce a smaller and narrower particle size distribution of Rh nanoparticles, whereas a HCl pre-treatment had no effect or sintered the Rh nanoparticles. We rationalise these results by HNO3 as an acid able to create new nucleation sites for Rh on the carbon surface, with the final effect of smaller nanoparticles, whereas for HCl the effect of sintering was most likely due to site blocking of the nucleation sites over the carbon surface. The roles of acid centres on the carbon surfaces for the oxidation reaction was also investigated, and the larger their amounts the larger the amounts of by-products. However, by treatment with HNO3 we were able to convert neutral or basic carbons into supports capable to enhance the catalytic activity of Rh, and yet minimised detrimental effects on the selectivity of the oxidation to benzaldehyde.
14

Estudo dos complexos organometálicos formados na etapa de extração de níquel e cobalto, através do uso de extratantes ácidos. / Study of organometallic complexes formed in the nickel and cobalt extraction step by the use of acidic extractants.

Murcia Santanilla, Adriana Johanny 18 April 2017 (has links)
O níquel e o cobalto são dois metais de ampla utilização na indústria mundial, principalmente na produção de aços inoxidáveis e ligas metálicas no caso do níquel, e baterias e superligas no caso do cobalto; estes dois metais são encontrados associados na natureza, cerca de 55% da produção mundial de cobalto é derivada da mineração de níquel. Porém, devido a estes elementos apresentarem comportamento químico similar em soluções aquosas, a sua purificação se torna difícil, impulsionando pesquisas voltadas para o melhoramento dos processos existentes para este fim. Dentre estes processos podemos citar a extração por solventes, e para um melhor entendimento da purificação de níquel e cobalto a partir dessa técnica, foi realizado esse estudo, o qual tem como objetivo estudar os complexos organometálicos formados na etapa de extração. A fase aquosa utilizada para a realização deste estudo é um licor sintético de lixiviação que contém níquel, cobalto, manganês, cobre, magnésio e cálcio na sua composição química. Por outro lado, a fase orgânica foi preparada com os extratantes ácidos Cyanex 272, Versatic 10 e D2EHPA de forma individual, assim como as suas misturas, como são: [Cy15-Ve5], [Cy10-Ve10], [Cy5-Ve15], [Cy15-DH5], [Cy10-DH10], [Cy5-DH15], [Ve15-DH5], [Ve10-DH10] e [Ve5-DH15]. Com o intuito de compreender a interação entre o extratante e o íon metálico (complexo organometálico), foi determinada a estequiometria dos complexos através dos métodos de análises da inclinação e o método da variação contínua (método de Job) e a caracterização foi feita utilizando as técnicas de espectrofotometria UV-Vis, espectroscopia FT-IR e termogravimetria (TG/DTG/DSC). Através dos resultados obtidos nos ensaios de extração, foram escolhidos os sistemas, [Cy15-Ve5] e [Cy10-DH10] para realizar o estudo dos complexos organometálicos. O método da variação contínua mostrou a participação de duas moléculas de extratante na complexação de cobalto em todas as fases orgânicas estudadas, com exceção do Versatic 10, a qual apresentou o envolvimento de 5 moléculas. Na complexação de níquel, foram encontradas uma molécula com D2EHPA e [Cy10-DH10], duas moléculas com Cyanex 272 e [Cy15-Ve5] e três moléculas com Versatic 10. As análises por UV-Vis forneceram o número de coordenação dos complexos organometálicos de níquel e cobalto formados tanto na solução aquosa como nas diferentes fases orgânicas estudadas. Através destes resultados determinou-se que o níquel apresentou uma simetria octaédrica nas condições testadas (fase aquosa e fases orgânicas), já o cobalto apresentou uma simetria octaédrica na solução aquosa e no Versatic 10, e simetria tetraédrica nas outras condições (Cyanex 272, D2EHPA e mistura dos extratantes). Por outro lado, as análises de infravermelho (FT-IR) mostraram que a extração do íon metálico é realizada através do mecanismo de troca catiônica (substituição do hidrogênio da ligação P-O-H). As análises termogravimétricas forneceram as temperaturas de decomposição dos complexos e, a presença ou não de moléculas de água no mesmo. Através destes resultados foi confirmado que os complexos de níquel se tratam de complexos hidratados, com exceção do complexo [Ni-Versatic 10], o qual corresponde a um complexo desidratado. Entretanto, os complexos organometálicos formados com o cobalto, são complexos desidratados, ou seja, que os sítios de coordenação estão completamente preenchidos por moléculas de extratante. / Nickel and cobalt are two metals widely used in the world industry, mainly in the production of stainless steel like an alloy element in the case of nickel, and both batteries and super alloys in the case of cobalt. These metals are found associated in nature and about 55% world production of cobalt is derived from the nickel mining. Due their similar chemical behavior in aqueous solution, its purification becomes difficult, encouraging research to improve the current processes, such as, the solvent extraction. In order to have a better understanding about both nickel and cobalt purification through this technique, this study has been carried out to evaluate the organometallic complexes formed during the extraction stage. The aqueous phase used in this study is a synthetic leach liquor containing in its chemical composition nickel, cobalt, manganese, copper, magnesium and calcium. On the other hand, the organic phase was prepared using the acidic extractants, as such: Cyanex 272, Versatic 10 and D2EHPA, as well as their mixtures [Cy15 Ve5], [Cy10-Ve10], [Cy5 Ve15], [Cy15-DH5], [Cy10-DH10], [Cy5 DH15], [Ve15-DH5], [Ve10-DH10] and [Ve5-DH15]. In order to understand the interaction between extractant molecule and metal ion (organometallic complex), the complex stoichiometry was determinate through two methods, such as: slope analysis and the continuous variation (Job´s method). Furthermore, the complex characterization was carried out using some techniques, spectrophotometry UV Vis, spectroscopy FT-IR and thermogravimetry (TG/DTG/DSC). The systems [Cy15-Ve5] and [Cy10-DH10] have been chosen in order to study the organometallic complexes formed. The continuous variation method has shown the participation of two extractant molecules in the complexation of cobalt in all organic phases studied in this work, except for the Versatic 10, where was observed the involvement of 5 molecules to form the complex. On the other hand, to form the nickel complex, when the D2EHPA and [Cy10-DH10] were used, five molecules were involved in the complex formation process. Furthermore, two molecules are present in the complex if Cyanex 272 or [Cy15-Ve5] are used like extractant and, when the Versatic 10 is used, three molecules are necessary to form the organometallic complex. The UV-Vis analysis provided the coordination number of the organometallic complexes of nickel and cobalt formed in both the aqueous and all organic phases chosen. It was determined that nickel showed an octahedral symmetry in both aqueous phase and organic phases, whereas the cobalt exhibited an octahedral symmetry both the aqueous solution and Versatic 10, and a tetrahedral symmetry in the other conditions (Cyanex 272, D2EHPA and extractants mixtures). Moreover, the infrared (FT-IR) analysis showed that the metal ion extraction is performed through the cation exchange mechanism (hydrogen substitution of P-O-H bond). Lastly, the thermogravimetric analysis provided the complexes decomposition temperatures and the presence or absence of water molecules. It was confirmed that nickel complexes are hydrated, except for the [Ni-Versatic 10] complex, which corresponds to a dehydrated complex. However, all organometallic complexes with cobalt are dehydrated complexes, that is, coordination sites are completely filled with extractant molecules.
15

FERROCENE-FUSED DERIVATIVES OF ACENES, TROPONES AND THIEPINS

Maharjan, Bidhya L. 01 January 2015 (has links)
This research project is concentrated on tuning the properties of small organic molecules, namely polyacenes, tropones and thiepins, by incorporating redox-active transition metal centers π-bonded to terminal cyclopentadienyl ligands. Organometallic-fused acenequinones, tropones, thiepins and cyclopentadiene-capped polyacenes were synthesized and characterized. This work was divided into three parts: first, the synthesis of ferrocene-fused acenequinones, cyclopentadiene-capped acenequinones and their subsequent aromatization to polyacenes; second, the synthesis of ferrocene-fused tropones, thiotropones and tropone oxime; and third, the synthesis of ferrocene-fused thiepins. Ferrocene-fused quinones are the precursors to our target complexes. Our synthetic route to ferrocenequinones involved two-fold aldol condensation between 1,2-diformylferrocene and naphthalene-1,4-diol or anthracene-1,4-diol, and four-fold condensation between 1,2-diformylferrocene and 1,4-cyclohexanedione. Reduction of ferrocene-fused quinones with borane in THF resulted in ferrocene-fused dihydroacenes. Attempts to reduce ferrocene-fused acenequinones with sodium dithionite led to metal-free cyclopentadiene- (Cp-) capped acenequinones. Cp-capped acenequinones were aromatized to bis(triisopropylsilyl)ethynyl polyacenes by using lithium (triisopropylsilyl)acetylide (TIPSC≡CLi) with subsequent dehydroxylation by stannous chloride. The compounds were characterized by using spectroscopic methods and X-ray crystallography. Further, the electronic properties of these compounds were studied by using cyclic voltammetry and UV-visible spectroscopy. Cyclic voltammetry showed oxidation potentials of Cp-capped TIPS-tetracene and bis-Cp-capped TIPS-anthracene as 0.49 V and 0.61 V, respectively (vs. ferrocene/ferrocenium). The electrochemical band gaps were 2.15 eV and 2.58 eV, respectively. Organic thin-film transistor device performance of Cp-capped polyacenes was studied using solution deposition bottom-contact, bottom-gate (BCBG) device architecture and the resulting performance parameters are described herein. Similarly, we are also interested in potential applications of metallocene-fused tropones and derivatives as organic electronic materials. Condensation of 1,2-diformylferrocene with acetone or 1,3-diphenylacetone in the presence of KOH resulted in the ferrocene-fused tropone (η5-2,4-cyclopentadien-1-yl)[(1,2,3,3a,8a-η)-1,6-dihydro-6-oxo-1-azulenyl]iron (1, R = H, E = O) and its 5,7-diphenyl derivative (1, R = Ph, E = O) as previously reported by Tirouflet. The use of piperidine as base resulted in Michael addition of piperidine to one of the carbon-carbon double bonds of the tropones. Lawesson’s reagent converted the ferrocene-fused tropones to either a thiotropone (1, R = H, E = S) or a detached 5,7-diphenylazulenethiol (2). Reaction of the ferrocene-fused thiotropone with hydroxylamine gave the corresponding oxime (1, R = H, E = NOH). Products were characterized by using spectroscopic methods and X-ray crystallography. Their electronic properties were studied by using cyclic voltammetry and UV-visible spectroscopy. The third project involved the two-fold aldol condensation of 1,2-diformylferrocene with dimethylthioglycolate S-oxide in the presence of freshly distilled triethylamine, which gave mono- and di-dehydrated products. Deoxygenation of the ferrocene-fused thiepin S-oxide with 2-chloro-1,3,2-benzodioxaphosphole in the presence of pyridine resulted in the corresponding thiepin. The ester groups of the thiepin and thiepin S-oxide were hydrolyzed under basic conditions to give carboxylic acids, which were converted into acid chlorides using oxalyl chloride. Attempts to decarboxylate the thiepin and thiepin S-oxide diacids resulted in decomposition.
16

Estudo dos complexos organometálicos formados na etapa de extração de níquel e cobalto, através do uso de extratantes ácidos. / Study of organometallic complexes formed in the nickel and cobalt extraction step by the use of acidic extractants.

Adriana Johanny Murcia Santanilla 18 April 2017 (has links)
O níquel e o cobalto são dois metais de ampla utilização na indústria mundial, principalmente na produção de aços inoxidáveis e ligas metálicas no caso do níquel, e baterias e superligas no caso do cobalto; estes dois metais são encontrados associados na natureza, cerca de 55% da produção mundial de cobalto é derivada da mineração de níquel. Porém, devido a estes elementos apresentarem comportamento químico similar em soluções aquosas, a sua purificação se torna difícil, impulsionando pesquisas voltadas para o melhoramento dos processos existentes para este fim. Dentre estes processos podemos citar a extração por solventes, e para um melhor entendimento da purificação de níquel e cobalto a partir dessa técnica, foi realizado esse estudo, o qual tem como objetivo estudar os complexos organometálicos formados na etapa de extração. A fase aquosa utilizada para a realização deste estudo é um licor sintético de lixiviação que contém níquel, cobalto, manganês, cobre, magnésio e cálcio na sua composição química. Por outro lado, a fase orgânica foi preparada com os extratantes ácidos Cyanex 272, Versatic 10 e D2EHPA de forma individual, assim como as suas misturas, como são: [Cy15-Ve5], [Cy10-Ve10], [Cy5-Ve15], [Cy15-DH5], [Cy10-DH10], [Cy5-DH15], [Ve15-DH5], [Ve10-DH10] e [Ve5-DH15]. Com o intuito de compreender a interação entre o extratante e o íon metálico (complexo organometálico), foi determinada a estequiometria dos complexos através dos métodos de análises da inclinação e o método da variação contínua (método de Job) e a caracterização foi feita utilizando as técnicas de espectrofotometria UV-Vis, espectroscopia FT-IR e termogravimetria (TG/DTG/DSC). Através dos resultados obtidos nos ensaios de extração, foram escolhidos os sistemas, [Cy15-Ve5] e [Cy10-DH10] para realizar o estudo dos complexos organometálicos. O método da variação contínua mostrou a participação de duas moléculas de extratante na complexação de cobalto em todas as fases orgânicas estudadas, com exceção do Versatic 10, a qual apresentou o envolvimento de 5 moléculas. Na complexação de níquel, foram encontradas uma molécula com D2EHPA e [Cy10-DH10], duas moléculas com Cyanex 272 e [Cy15-Ve5] e três moléculas com Versatic 10. As análises por UV-Vis forneceram o número de coordenação dos complexos organometálicos de níquel e cobalto formados tanto na solução aquosa como nas diferentes fases orgânicas estudadas. Através destes resultados determinou-se que o níquel apresentou uma simetria octaédrica nas condições testadas (fase aquosa e fases orgânicas), já o cobalto apresentou uma simetria octaédrica na solução aquosa e no Versatic 10, e simetria tetraédrica nas outras condições (Cyanex 272, D2EHPA e mistura dos extratantes). Por outro lado, as análises de infravermelho (FT-IR) mostraram que a extração do íon metálico é realizada através do mecanismo de troca catiônica (substituição do hidrogênio da ligação P-O-H). As análises termogravimétricas forneceram as temperaturas de decomposição dos complexos e, a presença ou não de moléculas de água no mesmo. Através destes resultados foi confirmado que os complexos de níquel se tratam de complexos hidratados, com exceção do complexo [Ni-Versatic 10], o qual corresponde a um complexo desidratado. Entretanto, os complexos organometálicos formados com o cobalto, são complexos desidratados, ou seja, que os sítios de coordenação estão completamente preenchidos por moléculas de extratante. / Nickel and cobalt are two metals widely used in the world industry, mainly in the production of stainless steel like an alloy element in the case of nickel, and both batteries and super alloys in the case of cobalt. These metals are found associated in nature and about 55% world production of cobalt is derived from the nickel mining. Due their similar chemical behavior in aqueous solution, its purification becomes difficult, encouraging research to improve the current processes, such as, the solvent extraction. In order to have a better understanding about both nickel and cobalt purification through this technique, this study has been carried out to evaluate the organometallic complexes formed during the extraction stage. The aqueous phase used in this study is a synthetic leach liquor containing in its chemical composition nickel, cobalt, manganese, copper, magnesium and calcium. On the other hand, the organic phase was prepared using the acidic extractants, as such: Cyanex 272, Versatic 10 and D2EHPA, as well as their mixtures [Cy15 Ve5], [Cy10-Ve10], [Cy5 Ve15], [Cy15-DH5], [Cy10-DH10], [Cy5 DH15], [Ve15-DH5], [Ve10-DH10] and [Ve5-DH15]. In order to understand the interaction between extractant molecule and metal ion (organometallic complex), the complex stoichiometry was determinate through two methods, such as: slope analysis and the continuous variation (Job´s method). Furthermore, the complex characterization was carried out using some techniques, spectrophotometry UV Vis, spectroscopy FT-IR and thermogravimetry (TG/DTG/DSC). The systems [Cy15-Ve5] and [Cy10-DH10] have been chosen in order to study the organometallic complexes formed. The continuous variation method has shown the participation of two extractant molecules in the complexation of cobalt in all organic phases studied in this work, except for the Versatic 10, where was observed the involvement of 5 molecules to form the complex. On the other hand, to form the nickel complex, when the D2EHPA and [Cy10-DH10] were used, five molecules were involved in the complex formation process. Furthermore, two molecules are present in the complex if Cyanex 272 or [Cy15-Ve5] are used like extractant and, when the Versatic 10 is used, three molecules are necessary to form the organometallic complex. The UV-Vis analysis provided the coordination number of the organometallic complexes of nickel and cobalt formed in both the aqueous and all organic phases chosen. It was determined that nickel showed an octahedral symmetry in both aqueous phase and organic phases, whereas the cobalt exhibited an octahedral symmetry both the aqueous solution and Versatic 10, and a tetrahedral symmetry in the other conditions (Cyanex 272, D2EHPA and extractants mixtures). Moreover, the infrared (FT-IR) analysis showed that the metal ion extraction is performed through the cation exchange mechanism (hydrogen substitution of P-O-H bond). Lastly, the thermogravimetric analysis provided the complexes decomposition temperatures and the presence or absence of water molecules. It was confirmed that nickel complexes are hydrated, except for the [Ni-Versatic 10] complex, which corresponds to a dehydrated complex. However, all organometallic complexes with cobalt are dehydrated complexes, that is, coordination sites are completely filled with extractant molecules.
17

Studium termodynamických a kinetických parametrů interakcí oligomerních modelů DNK s organokovovými komplexy aktivními v protirakovinné léčbě stanovených metodami kvantové chemie a kombinovanými QM/MM metodami / Studium termodynamických a kinetických parametrů interakcí oligomerních modelů DNK s organokovovými komplexy aktivními v protirakovinné léčbě stanovených metodami kvantové chemie a kombinovanými QM/MM metodami

Matunová, Petra January 2015 (has links)
It has been proven that platinum and ruthenium complexes are active in anti- cancer treatment. Nowadays, the common chemotherapeutica have a lot of side effects, therefore, drugs with fewer negative impacts are intensively searched for. The first part of the thesis focuses on the study of cis-[Pt(NH3)2Cl2] (cisplatin, DDP) and four platinum potential anticancer agents PtCl2(diaminocyclohexane), PtCl2(NH3)(cyclohexylamine) (JM118), cis-[PtCl2(NH3)(piperidine)] and trans-[PtCl2(NH3)(thiazole)]. Thermodynamic and kinetic parameters of reac- tions of these complexes in semi-hydrated and fully-hydrated form with guanine were studied using QM methods. The reaction with guanine is the key process ini- tiating the anticancer activity. Analyses of electron density were performed at the B3LYP/6-311++G(2df,2pd) level of theory in IEF-PCM model. The second part of the thesis studies the reaction of the so-called 'piano stool' Ru(II) transition metal complex, [Ru(II)(η6 -p-cymene(nalidixic acid)(H2O)]2+ , first with guanine using QM methods and second with ds-DNA model using QM/MM methods. The reaction site, which is described by QM method, is two consecutive guanines and the Ru(II) complex. Analyses of thermodynamic and kinetic parameters, and electron density were performed at the B97D/6-31G* level of theory. All the...
18

Laser-Ionization Time-of-Flight Mass Spectrometry of High Molecular Mass Inorganic Complexes

Watson, R. Craig Jr. 04 November 1997 (has links)
Laser-Ionization Time-of-Flight Mass Spectrometry (LI-TOF-MS) is a sophisticated tool for the molecular-weight determination and structural characterization of a variety of molecules. Advances in instrumentation and ionization methods have recently expanded its role in the analysis of high-mass analytes. Large multimetallic complexes, which are efficient solar-energy converters, rely heavily on their chemical structure for optimum operation. Molecular mass determinations of these multimetallic complexes have been problematic due to their lability and high molecular weights. This thesis describes the characterization of a LI-TOF-MS instrument and confirmation of theoretical time-of-flight mass-separation principles. Several test cases demonstrate the instrument's proper operation and calibration for a wide mass range of analytes. Mass spectral results of three organometallic compounds: i. [Ir(dpp)₂Cl₂](PF₆), ii. {[(bpy)₂Ru(dpp)]₂IrCl₂}(PF₆)₅, and iii. {[(bpy)₂Ru(dpp)]₂RuCl₂}(PF₆)₅ under a variety of laser ionization and sample preparation conditions are compared. A complete structural characterization of the monometallic complex, [Ir(dpp)₂Cl₂](PF₆), is presented. The two trimetallic analytes fragmented easily, but significant components of the molecules are successfully identified. After optimizing the ionization and analytical procedure, LI-TOF-MS proved useful in the analysis of high molecular mass metal complexes. / Master of Science
19

Ingéniérie, synthèse et étude de chromophores organiques et organométalliques pour cellules solaires à colorant / Design, synthesis and study of organic and organometallic dyes for dye-sensitized solar cells

De Sousa, Samuel 05 December 2013 (has links)
Le principal objectif de ce travail de thèse était d’imaginer, de synthétiser et de caractériser de nouveaux chromophores «push-pull» pour finalement évaluer leurs propriétés photovoltaïques en cellules solaires à colorant. Deux approches distinctes ont été développées : i) la première consiste en l’élaboration de chromophores tout-organiques de type « push-pull » basés sur un motif électro-donneur carbazole à potentiel d’oxydation élevé. Ces nouveaux colorants ont été conçus dans le but d’être utilisés avec des électrolytes à potentiel standard supérieur à celui du couple rédox I-/I3- ; ii) la seconde approche est basée sur un nouveau concept de chromophores organométalliques de type ruthénium-acétylure. Ces chromophores ont été développés dans le but de combiner à la fois les propriétés avantageuses d’une structure de type « push-pull » et les transferts de charges (MLCT) impliquant le motif [Ru(dppe)2], également connu pour constituer un excellent relai électronique. / The aim of this PhD research work was to design, synthesize and characterize new push-pull chromophores and finally to determine their photovoltaic properties in dye-sensitized solar cells. Two different approaches were developed: i) the first one consists in the preparation of metal-free organic push-pull chromophores based on a carbazole electron-donor part presenting high oxidation potential. These new chromophores were designed in view of being used with electrolytes showing standard potential superior to that of I-/I3-; redox couple ii) the second approach is based on a new concept of ruthenium-diacetylide organometallic complex dyes. These chromophores were developed in order to combine the advantageous properties of a push-pull structure and the charge transfer processes (MLCT) due to the [Ru(dppe)2] metal fragment, also known as an excellent electron relay.
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Synthesis, physicochemical and biological evaluation studies of ruthenium(II) and osmium(II) anticancer organometallic complexes

Boff, Bastien 11 February 2012 (has links) (PDF)
Since the clinical success of platinum drugs (cisplatin and its derivatives) as anticancer agent, medicinal inorganic chemistry has become a field of growing interest because it offers an alternative for the design of therapeutic agents that are not readily available to organic compounds. Although cisplatin is one of the most widely used drugs in chemotherapy, it is not effective for all types of cancer. Moreover, platinum drugs are the cause of disabling side effects (neurotoxicity, nephrotoxicity, weight loss, nausea...) and their applicability is limited by innate or induced resistance to platinum in a narrow range of tumours. Therefore, this clinical success has promoted the search for cytotoxic compounds with enhanced activities and more acceptable toxicity profiles. This has stimulated interest in complexes containing other heavy metals of the platinum group such as ruthenium because these compounds show lower toxicity than drugs based on platinum. Some ruthenium compounds have already shown promising anticancer activity and two RuIII complexes trans-[RuCl4-(DMSO)(Im)]ImH (NAMI-A and trans-[RuCl4(Ind)2]IndH (KP1019) recently enter in clinical phase for their respectively antimetastatic and cytotoxic properties.In the essential aim of increasing activity and reducing side effects of anticancer agents, the Laboratoire de Synthèses Métallo-Induites has developed for several years organometallic ruthenium compounds RDC (Ruthenium Derivative Compound) in which one of the ligand is strongly bound to the metal via a strong σ C-Ru bond and stabilized by an intramolecular N-Ru bond. This thesis presents the recent advances of the laboratory in this field and the development of a second generation RDC in which the cylometallating ligand is stabilized by two N-Ru bonds. Thus, several complexes pass the symbolic barrier of the nanomolar range for their IC50 indicating a critical improvement. At the same time, we decided to focus our studies on osmium heavier congener, not only to complete the RDC chemical library, but also to verify the impact of exchanging the metal. An extensive chemical library ODC (Osmium Derivative Compound) of forty cyclometalated osmium complexes was synthesized and evaluated in vitro. Biological studies on these ODCs showed that osmium is another metal that deserves attention for the development of new effective antitumour drugs. The measurements of physicochemical properties such as red-ox potential and lipophylicity (log(Po/w)) allowed us to tentatively correlate these parameters to the level of activity, thus approaching a possible Property-Activity Relationship (P.A.R.). More insight into the role of the red-ox potential will probably become clearer as we progress into the mechanism of action of these species.

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