Les travaux de recherche doctorale présentés dans ce manuscrit traitent de l'utilisation de ligands organométalliques associés à des briques organométalliques luminophores. Ces ligands rganométalliques, appelés organométalloligands sont des complexes sandwichs où un ruthénium(II) ou un iridium(III) est -coordonné à un cycle portant une ou deux fonctions chélatantes. Ces fonctions sont des atomes de soufre ou de sélénium. Les briques luminophores sont constituées d'un atome de platine(II) complexé par des ligands aromatiques. En faisant varier la topologie des organométalloligands employés ainsi que le type de briques de platine, des assemblages polynucléaires variés sont obtenus. Pour chaque famille d'assemblages synthétisés, une étude des propriétés d'absorption et de luminescence est menée. Au travers de ces divers assemblages, différents aspects particulier de la chimie de coordination sont mis en avant. Ainsi, nous pouvons avec un organométalloligand servant d'espaceur créer des chaînes monodimensionnelles, leur formation étant assurée par des interactions de type supramoléculaires Pt···Pt et - . La stratégie de l'organométalloligand permet par ailleurs d'amoindrir le caractère non-innocent d'un ligand dithiolène complexé à une brique de platine luminescente, ce qui peut être confirmé par étude électrochimique. Enfin, la synthèse d'un organométalloligand portant une information chirale mène, en contrôlant cette chiralité, à moduler les agrégations intermoléculaires ce qui permet d'observer une modulation en terme de luminescence. / The PhD research work presented herein deals with the use of organometallic ligands as connectors to luminescent organometallic building blocks to provide novel luminescent coordination assemblies. These organometallic ligands, called "organometalloligands" are sandwich-complexes where a ruthenium(II) or an iridium(III) is pi-bonded to a carbo-cycle bearing one or two chelating ligands. These ligands are either sulfur or selenium atoms. The luminescent building blocks are basically cyclometallated platinum(II) or polypyridyl Pt(II) moieties. Upon variation of the geometrical structures of the organometalloligands as well as the platinum luminophores, various polynuclear assemblies displaying unique appealing architectures are obtained. Moreover for each type of coordination assembly, a full investigation of their absorption and emission properties is presented. For instance, such assemblies with organometalloligand spacer display 1D infinite chains, where the individual units exhibit supramolecular Pt···Pt and pi-pi interactions. On the other hand, the non-innocent character of the pi-bonded dithiolene ligand is controlled as it is shown by electrochemistry experiments. Finally, the synthesis of a novel organometalloligand bearing chiral function allows, the control of the chirality of the assemblies, the modulation of the intermolecular Pt···Pt and pi-pi interactions and overall their luminescent properties.

Title: Copper(I) complexes with phosphinonitrile donors Author: Bc. Filip Horký Department: Department of Inorganic chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. Abstract: Although coordination compounds with phosphinonitrile ligands are already well known, in the vast majority of these complexes these ligands coordinate as simple P-donors with their cyano groups acting as auxiliary substituents. This led us to synthesize and study a series of Cu(I) complexes with two isomeric phosphinonitrile donors, namely 2-(diphenylphosphino)benzonitrile (Lo ) and 2-(diphenylphosphino)benzonitrile (Lp ), with different ligand-to-metal ratios and possibly characterize further coordination modes offered by these hybrid donors. This work describes the preparation of phosphinonitrile complexes from the aforementioned ligands and simple copper(I) halides (CuX, X = Cl, Br, I), pseudohalides (X = CN) and from [Cu(MeCN)4][BF4]. The products were characterized by nuclear magnetic resonance, infrared spectroscopy and elemental analysis, mass spectrometry, and their solid-state structures were determined by single-crystal X-ray crystallography. In addition, luminescent properties of the Cu(I) complexes were studied and catalytic activity of selected complexes was tested in copper-catalyzed alkyne-azide cycloaddition...

Le pigment blanc de plomb, composé de deux phases cristallines carbonates de plomb (cérusite PbCO3 et hydrocérusite 2PbCO3.Pb(OH)2) est synthétisé et utilisé en peinture depuis l'Antiquité. L'étude des sources historiques révèle que les artistes pouvaient se procurer des qualités variées de ce matériau, selon le degré de sophistication de la synthèse. Particulièrement, l'amélioration des propriétés optiques du pigment était recherchée. Notre travail, fondé sur la combinaison d'une caractérisation micro-structurale par diffraction des rayons X et optique par étude de la luminescence des deux phases d'intérêt a permis une meilleure compréhension de ces qualités. Une étude cristallochimique a précisé les mécanismes de formation des phases apparaissant au cours de la synthèse du pigment par corrosion du plomb métallique, et démontré l'influence des procédés antiques sur les paramètres de composition et de microstructure du pigment (morphologie des cristallites à l'échelle nanométrique). En utilisant différentes configurations d'analyse DRX (notamment fondées sur le rayonnement Synchrotron), combinées à l'affinement Rietveld, il a été possible de remonter à ces paramètres structuraux au sein même des couches de blanc de plomb d'¿uvres peintes du Musée du Louvre, notamment un ensemble d'¿uvres de Léonard de Vinci. Les résultats ont été complétés par l'étude de la photoluminescence des blancs de plomb induite par rayonnement laser. Le mécanisme de cette luminescence a ainsi été précisé. Les propriétés optiques ont enfin été connectées aux paramètres structuraux et aux traitements utilisés dans le passé visant à obtenir un pigment aux qualités maitrisées. / The lead white pigment, composed of two main mineral phases (cerussite PbCO3 and hydrocerussite 2PbCO3.Pb(OH)2) has been synthesized and used in paintings since the Antiquity. The study of historical sources reveals that a large variety of lead white qualities that painters could select existed, according to the degree of sophistication of the synthesis.This work, based on the combination of micro-structural and optical characterization, using X-ray diffraction (XRD) and luminescence properties, has permitted a better understanding of those pigment qualities. In a first time, a cristallo-chemical study was performed to specify the formation mechanisms of the crystalline phases during the antique synthesis, based on the corrosion of metallic lead. The impact of post-synthesis processes on the composition and the microstructure of the pigment was highlighted. Using several XRD analysis configurations (in particular based on the Synchrotron radiation) combined with Rietveld refinement, it was possible to gain insight on those parameters within lead white-based paint layers of prestigious paintworks of the Louvre Museum. Those results have been completed by the laser-induced photoluminescence study of lead white pigments. The mechanism of this luminescence has been defined. In addition, the optical properties have been connected to the structural parameters, and to the post-synthesis processes used to obtain high quality pigments in the past. Luminescence can be used as a probe of the pigment history.

No description available.

La première partie de ce travail porte sur l’élaboration et la caractérisation de nouvelles nanoparticules (NPs) multifonctionnelles de silice à architectures complexes. L’enjeu est de répondre à la demande croissante d’élaboration de nouveaux systèmes colloïdaux non toxiques, magnétiques et/ou luminescents dans la région NIR pour des applications potentielles en biotechnologie. Cet objectif a été atteint en associant intimement des composés à clusters de molybdène avec des nanocristaux de maghémite et/ou d’or dans une NPs de silice de 50 nm. Une évaluation de la cytotoxicité des NPs contenant des clusters d’éléments de transition Cs2Mo6Br14 ainsi qu’un suivi par microscopie de fluorescence en temps retardé des NPs Cs2Mo6I8(C2F5COO)6@SiO2 incorporées dans des cellules cancéreuses sont présentés. Dans la deuxième partie, des poudres microcristallines de composés hétéronucléaires de polymères de coordination à base de terres rares de formule chimique générale [Ln2-2xLn’2x(bdc)3,4H2O]∞ avec 0 ≤ x ≤ 1 ont été nanométrisées dans du glycérol. Ces NPs présentent des propriétés luminescentes identiques à celles du matériau massif. Une étude détaillée de cette nouvelle voie de synthèse répondant aux principes de la chimie verte ainsi qu’une étude de la stabilité en fonction du temps et de la dilution des colloïdes obtenus ont été réalisées. / The first part of this work involves the development and characterization ofnovel nanoparticles (NPs) of multifunctional silica with complex architectures.The challenge is to meet the increasing demand for development of newnon-toxic colloidal systems, magnetic and/or luminescent in the NIR regionfor potential applications in biotechnology. This objective was achievedby closely associating molybdenum clusters compounds with maghemitenanocrystals and/or gold in 50 nm silica NPs. An evaluation of thecytotoxicity of NPs containing clusters of transition elements of Cs2Mo6Br14and a time-gated fluorescence microscopy of Cs2Mo6I8(C2F5COO)6@SiO2NPs incorporated in cancer cells are presented.In the second part, microcrystalline powders of heteronuclear lanthanidebasedcoordination polymers with general chemical formula [Ln2-2xLn’2x(bdc)3,4H2O] ∞ 0 ≤ x ≤ 1 were dissolved in glycerol . These NPsexhibit luminescent properties identical to that of the bulk material.A detailed study of this new green synthetic route and a study of thestability over time and a dilution of the obtained colloids were performed.

Les cristaux dopés par des ions de terre rare (TR) apparaissent prometteurs pour des applications dans le traitement quantique de l'information. Parmi ces matériaux, les cristaux massifs d'Eu3+:Y2O3 présentent un long temps de cohérence optique (T2), un paramètre fondamental pour les technologies quantiques. Ce travail de thèse porte sur l'étude de ce système à l'échelle nanométrique, ce qui pourrait permettre de développer des systèmes hybrides dans lesquels les TR sont couplées à d'autres systèmes quantiques. Des nanocristaux de différentes tailles ont été élaborés par précipitation homogène. La largeur optique inhomogène diminue avec des recuits à haute température et peut atteindre les valeurs mesurées dans des cristaux massifs. Une corrélation quasi-linéaire avec les largeurs de raie Raman a aussi été observée. Les temps de vie de population sont plus longs que dans les échantillons massifs et peuvent être modélisés par un indice de réfraction effectif. Les T2 optiques ont ensuite été déterminés par écho de photon et creusement de trou spectral. Nous avons mesuré un temps de cohérence de 7.1 µs à 1.7 K dans un échantillon dopé à 0.5 % en Eu3+, la valeur la plus élevée observée pour un nanocristal. Une étude en température et de la diffusion spectrale indique que le déphasage est dominé par des fluctuations de la structure et des basculements de spins. / Rare earth (RE) doped crystals are promising materials for quantum information processing (QIP). In particular, Eu3+:Y2O3 bulk crystals present long optical coherent lifetimes (T2), a fundamental parameter for QIP. In this thesis, we investigated this system at the nanoscale, which could be used to build hybrid devices where RE are coupled to other quantum systems. This work focuses on the development of Eu3+: Y2O3 particles with sub-wavelength size and on the static and dynamical contributions to Eu3+ optical linewidth. Systems with different particle and crystallite sizes were prepared using homogeneous precipitation. Optical inhomogeneous linewidths were found to decrease with high temperature annealing and reached values close to those of bulk crystals, showing that low defect concentrations can be obtained. A quasi-linear correlation with Raman linewidths was also observed. T1 population decays were measured by fluorescence and found longer than in the bulk, in good agreement with a model based on an effective refractive index model. Optical T2 were investigated by photon echo (PE) and holeburning techniques. We observed a coherence lifetime of 7.1 µs at 1.7 K in a 0.5 % Eu3+ doped sample, the highest value reported for any nanocrystal. Temperature dependence and spectral diffusion studies indicate that structure fluctuations and spin flips dominate dephasing.

Multi-junction photovoltaic devices based on III-V semiconductors have applications in space power systems and terrestrial concentrating photovoltaics, as well as in power-over-fibre and optical power conversion systems. These devices have between two and twenty junctions arranged in tandem, connected in series with optically transparent tunnel diodes. In some cases, they may include as many as eight different materials, including ternary and quaternary alloys, and >100 epitaxial layers in total. A general method for simulating performance of these devices using drift-diffusion based device simulation tools is reviewed. This includes discussion of the geometry, discretization, and physical equations to be solved. A set of material parameters for some important materials is listed, and solutions are shown for an example of a lattice-matched four-junction GaInP / (In)AlGaAs / InGaAsN(Sb) / Ge solar cell including a dilute nitride based p-i-n junction with ∼ 0.9 eV band gap. A sample of this dilute nitride junction with a 650 nm absorber layer was grown by molecular beam epitaxy and was shown to have short-circuit current density of 15.1 mA/cm2, sufficient for use in the 4-junction structure, while transmitting sufficient light through to the bottom (germanium) junction. Open-circuit voltage was up to 0.186 V at 1-sun, increasing to 0.436 V under 1500 suns concentration. The device simulation methodology was extended to include effects of luminescent coupling and photon recycling. These effects are included by adding a term to the electron and hole continuity equations, and the resulting coupled system of equations is solved. No external iterative loop is required, as has been the case in other efforts to model these effects. A five-junction photonic power converter (PPC) is simulated and it is shown that the quantum efficiency of the device is significantly broadened through luminescent coupling. There is a 350 mV reduction in simulated open-circuit voltage (70 mV per junction) if luminescent coupling is neglected. This work was later extended to a 12-junction PPC device, where the simulation predicts a wavelength sensitivity of -1.1%/nm in the absence of luminescent coupling; this is reduced to -0.4%/nm when luminescent coupling is included in the calculation. The latter result, and the overall shape of the simulated quantum efficiency curve agree closely with experimental measurements. Finally, two specific applications of PPCs are demonstrated. The first is in a step-up DC-to-DC converter, where a linear regulator combined with a laser/PPC pair can convert a 3.3 V input (commonly available from a single lithium polymer battery cell) into 12 V. Unlike conventional switching boost converters, this ‘photonic boost converter’ is not a source of ripple. In testing, a >80 dB reduction in ripple was measured compared with an equivalent switching boost converter, limited only by input noise of the instrument.The second application is in a 60 kW, 650 V switching circuit such as might be found in a hybrid or electric vehicle drivetrain. These circuits need several isolated power supplies to power gate drivers for the IGBT or SiC MOSFET switching components. This isolation is commonly provided by a small transformer, which inherently has a parasitic capacitance between primary and secondary windings and creates a path for EMI currents to flow from the high-power components to the power supply and control circuitry. By using a laser/PPC pair to provide the needed isolation, this parasitic capacitance can be largely eliminated; a 20 dB reduction in EMI current reaching the control FPGA is demonstrated.

Glacial-interglacial cycles drive changes in the discharge and sediment flux from the headwaters of glaciated basins, which are recorded by proglacial fluvial sediments. Linking braided river stratigraphy to the Quaternary climate record could indicate the control of climate-driven variations in discharge and sediment flux on fluvial processes, and the magnitude and frequency of past climate variations. New Zealand is a key location for investigating terrestrial records of Southern Hemisphere climate change. The Late Quaternary braided river deposits on the Canterbury Plains, South Island, New Zealand have formed over the last 400 ka. The coastal cliff marking the southeastern margin of the Canterbury Plains provides excellent exposure of fluvial sediments deposited during the last glacial period, from ~40 ka until the end of the Last Glacial Maximum (LGM) (~18 ka).Deposition at the modern coastline of the Canterbury Plains is interpreted in the context of the climate event stratigraphy for New Zealand, which requires a precise geochronology. This thesis demonstrates the first successful application of optically stimulated luminescence (OSL) dating to glaciofluvial sediments on South Island: a technique that was previously considered unsuitable for this region. Ages produced for the coastal stratigraphy range from 36.7 ± 2.9 to 18.2 ± 1.3 ka, indicating that deposition took place during the last glacial, with little or no postglacial aggradation. Three adjacent catchments on the southern Canterbury Plains - the Rakaia, Ashburton and Rangitata - have undergone glacial-drainage capture during the period represented by the coastal stratigraphy. During glacials, transfluent ice reversed the flow direction in several key tributaries, resulting in dramatic variations in effective drainage area of the Ashburton and Rangitata, and variations in discharge and sediment flux which are recorded in the stratigraphy of these catchments. The magnitude, timing and duration of drainage capture were quantified using the Plummer and Phillips (2003) glacier model. The Ashburton catchment increased to 160% of the modern effective drainage area when temperature change relative to modern conditions exceeded -6°C during the LGM. Meanwhile, the effective drainage area of the Rangitata decreased to 63%, and the Rakaia to 93%, reducing discharge from these catchments. Furthermore, glaciation dramatically affects the seasonality of the annual hydrograph. At four coastal sites, the fluvial stratigraphy was surveyed to investigate possible variations in depositional architecture, due to both climate variations, and glacial-drainage capture in the Ashburton and Rangitata. Unexpectedly, little vertical variation in depositional architecture was found, indicating that the deposits created by the braided rivers represent sediment transport during a similar set of flow (and by inference, climate) conditions. Laterally extensive erosional surfaces separating storeys of one or two flow depths in thickness, in combination with the OSL geochronology, suggest that the gravel-bed braided river stratigraphy primarily records a response to climate variations within glacial maxima, rather than on the scale of the glacial-interglacial cycle.

The major topics discussed are the phosphorescence sensitization in the lanthanides via energy transfer and in the organics by heavy atom effects. The f-f transitions in lanthanides are parity forbidden and have weak molar extinction coefficients. Upon complexation with the ligand, ttrpy (4'-p-Tolyl-[2,2':6',2"]-terpyridine) the absorption takes place through the ligand and the excitation is transferred to the lanthanides, which in turn emit. This process is known as "sensitized luminescence." Bright red emission from europium and bright green emission from terbium complexes were observed. There is ongoing work on the making of OLEDs with neutral complexes of lanthanide hexafluoroacetyl acetonate/ttrpy, studied in this dissertation. Attempts to observe analogous energy transfer from the inorganic donor complexes of Au(I) thiocyanates were unsuccessful due to poor overlap of the emissions of these systems with the absorptions of Eu(III) and Tb(III). Photophysics of silver-aromatic complexes deals with the enhancement of phosphorescence in the aromatics. The heavy atom effect of the silver is responsible for this enhancement in phosphorescence. Aromatics such as naphthalene, perylene, anthracene and pyrene were involved in this study. Stern Volmer plots were studied by performing the quenching studies. The quenchers employed were both heavy metals such as silver and thallium and lighter metal like potassium. Dynamic quenching as the predominant phenomenon was noticed.

Interest in the synthesis of novel luminescent lanthanide complexes stems from the wide area of application in various fields of science. Thus, the theoretical design becomes an important tool in the search for efficient luminescent complex. Within this context, emerged the Sparkle model that were developed for predicting the ground state geometries of lanthanide complexes. In this work we present a new parameterization of the ion Eu (III) for the AM1 and RM1 semiempirical methods, with the explicit inclusion of orbitals s, p and d in the basis set. With this reasoning, we have limitations in the calculation of lanthanide complexes in the solvent with MOPAC and initiate an improvement in the description of links that show the highest degree of covalency. The parameterization process of this model had a robust statistical analysis to select the set of parameterization, since our whole universe has 144 structures of lanthanide complexes. Thus, we used two methods to identify the structures that should be part of the parameter set: (i) the method of hierarchical grouping known as AGNES and (ii) the DIANA method. The models that we developed (AM1/Eu and RM1/Eu) showed an improvement compared to the versions of the Sparkle model, considering the low average absolute errors for the distances Eu L (L = O, N, C, S, P, F, Cl, Br and Eu), maintaining the commitment to the low computational cost involved in performing the calculations of the geometries of the ground state. We also investigated the accuracy of quantum-chemical methods in the reproduction of the coordination polyhedron of lanthanide ion complexes. We compared semiempirical methods (the PCC approach and Sparkle model) and also those with the ab initio methodology RHF/ECP/STO-3G. After this study, we conclude that the only semiempirical Sparkle model (hundreds of times faster) present similar accuracy to what can be obtained by present-day ab initio/ECP full geometry optimization calculations on such lanthanide complexes. In addiction it further indicates that the PCC approach is inappropriate to predict the coordination polyhedron geometries of lanthanide complexes. / O interesse na síntese de novos complexos de lantanídeos luminescentes advém da vasta área de aplicação em diversos campos da ciência. Deste modo, o design teórico torna-se uma importante ferramenta na busca de eficientes complexos luminescentes. Dentro desse contexto, surgiram as versões do modelo Sparkle que foram desenvolvidas para a predição da geometria do estado fundamental de complexos de lantanídeos. Nesta dissertação, buscaremos parametrizar o íon Eu(III) para os métodos semiempíricos AM1 e RM1, com a inclusão explícita de orbitais do tipo s, p e d no conjunto de base. Com essa fundamentação, acabamos com limitações no cálculo de complexos lantanídicos em meio solvente com o MOPAC e iniciamos uma melhoria na descrição de ligações com grau de covalência mais elevados. O processo de parametrização deste modelo contou com uma análise estatística robusta para a seleção do conjunto de parametrização, uma vez que o nosso conjunto universo apresenta 144 estruturas de complexos de európio. Desta forma, utilizamos dois métodos para identificar as estruturas que deveriam fazer parte do conjunto de parametrização: (i) o método hierárquico de agrupamento conhecido como AGNES e (ii) o método de desagrupamento DIANA. Os modelos que desenvolvemos (AM1/Eu e RM1/Eu) mostraram uma evolução em relação às versões do modelo Sparkle, tendo em vista os baixos erros médios absolutos para as distâncias Eu L, (L = O, N, C, S, P, F, Cl, Br e Eu), mantendo o compromisso com o baixo custo computacional envolvido na execução dos cálculos das geometrias do estado fundamental. Também investigamos a exatidão dos métodos químico-quânticos na reprodução do poliedro de coordenação de complexos de íons lantanídeos. Nós comparamos métodos semiempiricos (a abordagem PCC e o modelo Sparkle) e ainda esses com a metodologia ab initio RHF/ECP/STO-3G. Após este estudo, concluímos que a abordagem PCC é ineficiente para reproduzir o poliedro de coordenação cristalográfico desses complexos. Os resultados obtidos confirmaram também que os modelos Sparkle apresentam exatidão semelhante, à que pode ser obtida pela otimização completa da geometria, utilizando as atuais metodologias ab initio/ECP.