Correlated many-particle dynamics in Coulombic systems is one of today‟s grand challenges in physics. In order to address this task, the electronic structure and electron correlations of multiply ionised systems are studied in this thesis, aiming to obtain information on the dynamics of electron emission processes at unprecedented ease and high resolution. State-of-the-art multi-electron correlation spectrometers are used, which were originally developed at Oxford University, UK, and which are now frequently in use at the Ångström laboratory in Uppsala, Sweden.The research is so far based mainly on single-photon excitations using laboratory light sources and synchrotron radiation facilities, and expands now gradually into non-linear and time-resolved studies of atoms, molecules and clusters using high intensive Free Electron Lasers (FEL) in the Vacuum Ultra-Violet (VUV) and X-ray spectral region. This development is highly relevant for even more deep-going applications regarding the ion and excited-state balance in the Earth‟s outer atmosphere and in astrophysical contexts, for photochemistry and biochemistry, for materials science, and to test current atomic and molecular structure theories to their limits.We will focus on the multiple ionization of the buckminsterfullerene (C60) which is of scientific interest as an exceptionally stable and symmetric cluster. Its applications are quite large in nanotechnologies.

In this work we will discuss fragmentation and molecular growth processes in collisions of Polycyclic Aromatic Hydrocarbon (PAH) molecules, fullerenes, or their clusters with atoms or atomic ions. Simple collision models as well as molecular structure calculations are used to aid the interpretations of the present and other experimental results. Fragmentation features at center-of-mass collision energies around 10 keV are dominated by interactions between the fast ion/atom and the electron cloud in the molecules/clusters (electronic stopping processes). This electronic excitation energy is rapidly distributed on the vibrational degrees of freedom of the molecule or of the molecules in a cluster and may result in fragmentation. Here, the fragmentation is statistical and favors the lowest-energy dissociation channels which are losses of intact molecules from clusters, H- and C2H2-losses from isolated PAHs, and C2-loss from fullerene monomers. We will also discuss the possibility of formation of molecular H2 direct from native PAHs which reach high enough energies when interacting with ions, electrons, or photons. For the experiments at lower center of mass collision energies (~100 eV) a single atom may be knocked out in close atom-atom interaction. Such non-statistical fragmentation are due to nuclear stopping processes and gives highly reactive fragments which may form covalent bonds with other molecules in a cluster on very short time scales (picoseconds). This process may be important when considering the formation of new species. For collision between 12 keV Ar2+ and clusters of pyrene (C16H10) molecules, new molecules, e.g. C17H10+, C30H18+, C31H19+, etc are detected. We also observe molecular fusion processes for He and Ar ions colliding with clusters of C60 molecules. These and related molecular fusion processes may play a key role for understanding molecular growth processes under certain astrophysical conditions.

Nos travaux antérieurs ont développé la débenzylation DIBAL-H de α-, β- et γ-CDBn, qui génère une fonctionnalisation regiosélective sur le bord primaire. De plus, la déméthylation DIBAL-H de α- et β-CDMe donne accès à une modification régiosélective sur le bord secondaire sans changer la conformation de l'unité suger. La déméthylation DIBAL-H optimisée pourrait également influer sur la modification du bord primaire. En raison de la grande cavité du γ-CD sur la solubilisation et l'encapsulation C60, l'un des objectifs de mon travail est d'obtenir le γ-CDMe sélectivement modifié sur le bord secondaire. Sur la base de la déméthylation DIBAL-H de α-, β- et γ-CDMe, 7 conjugués α-CD-C60 sont soumis à l'évaluation biologique en tant qu'agents antiviraux potentiels et un conjugué β-CD-C60 est en cours d'étude en tant que potentiel anti-allergique agent. En outre, le conjugué 2A-γ-CDMe-C60 avec attachement de jante secondaire présente la plus grande solubilité dans l'eau parmi les conjugués CD-C60 et les complexes γ-CD / C60. Le conjugué 2A-γ-CDMe-C60 et le conjugué 6A-γ-CDMe-C60 avec fixation du jonc primaire ont montré un rendement quantique 1O2 plus élevé que les conjugués CD-C60 rapportés sous irradiation UV. À la lumière de la méthodologie de la débenzylation DIBAL-H, 6 complexes α- et β-CDMe-Ag hydrosolubles (Cu, Au) ont été synthétisés. On a obtenu des structures cristallines à rayons X d'α-CDMe-AgCl à la fois dans CDCl3 et dans de l'eau. Par ailleurs, nous avons obtenu le monomère α-CDMe-CuCCPh qui est stable dans l'eau. De plus, α- et β-CDMe-AuCl ont été comme catalyseurs en cyclosomérisation regiosélective, énantiéselective et lactonisation dans DCM et eau. / Our previous work have developed DIBAL-H debenzylation of α-, β- and γ-CDBn, which generates regioselective functionalization on the primary rim. Moreover, DIBAL-H demethylation of α- and β-CDMe gives an access to regioselective modification on the secondary rim without changing the conformation of suger unit. Meanwhile, the optimized DIBAL-H demethylation could affordes the modification on the primary rim as well. Because of the large cavity of γ-CD on C60 solubilization and encapsulation, one of the goals of my work is to obtain the selectively modified γ-CDMe on the secondary rim. Based on DIBAL-H demethylation of α-, β- and γ-CDMe, 7 α-CD-C60 conjugates are under the biological evaluation as potential antiviral agents and a β-CD-C60 conjugate is being studied as a potential anti-allergic agent. Furthermore, 2A-γ-CDMe-C60 conjugate with secondary rim attachement displays the highest water-solubility among CD-C60 conjugates and γ-CD/C60 complexes. Both 2A-γ-CDMe-C60 conjugate and 6A-γ-CDMe-C60 conjugate with primary rim attachment showed higher 1O2 quantume yield than the reported CD-C60 conjugates under UV irradiation. In light of the methodology of DIBAL-H debenzylation, 6 water-soluble α- and β-CDMe-Ag(Cu, Au) complexes have been synthesized. X-ray crystal structures of α-CDMe-AgCl in both CDCl3 and water have been obtained. Besides, we got monomer α-CDMe-CuCCPh which is stable in water. In addition, α- and β-CDMe-AuCl have been as catalysts in regioselective, enantioselective cycloisomerization and lactonization in DCM and neat water.

El treball d'aquesta Tesi es pot dividir principalment en tres parts. La primera part es basa en l'estudi de les propietats elèctriques de sistemes tipus tríada (donador-acceptor-donador) formats per una molècula de fullerè i dues de derivats del tetratiafulvalè (TTF). Per HPLC es van poder separar quatre dels isòmers majoritaris de la tríada i es van caracteritzar per UV-Vis i HMBC RMN. Els espectres d'EPR dels cations-radicals derivats són idèntics per tots els isòmers i quan es té l'espècie de valència mixta no es va observar, en cap cas en les condicions assajades, transferència electrònica entre els dos TTF's a través dels diferents fragments de C60. D'altra banda, tant els càlculs semi-empírics com els estudis d'EPR dels anions-radicals derivats posen de manifest que la densitat de spin difereix en els diferents isòmers estudiats. Aquesta metodologia pot ser útil per la caracterització i el disseny de noves tríades que puguin presentar transferències intramoleculars mediades pel fullerè.La segona part de la Tesi es basa en l'obtenció i estudi de sals iòniques radicalàries (SIR's) de derivats de donadors tipus TTF que presenten interessants propietats elèctriques i magnètiques. En l'estudi de SIR's utilitzant anions del tipus [Cr(NCS)4(N-donador)2]n- que poden presentar interaccions de tipus S···S i/o interaccions p-p, es va demostrar que aquest segon tipus d'interaccions és el responsable de que pugui haver ordenament magnètic de llarg abast en aquest tipus de sals. D'altra banda, basant-nos amb la sal (DT-TTF)2Au(mnt)2 que constituí la primera escala de spin orgànica i amb l'objectiu d'obtenir noves escales de spin moleculars, es van sintetitzar i caracteritzar noves SIR utilitzant dues estratègies diferents: i) modificant el donador tetratiafulvalènic; ii) modificant el complex aniònic. L'estratègia d'utilitzar el mateix donador aromàtic DT-TTF i diferents anions dóna resultats més satisfactoris i pot donar lloc a compostos que també presenten escales de spin.Finalment, en la darrera part de la Tesi es demostra que la tècnica Modified Reticulate Doping Technique (MRDT) permet preparar films bicapa (bi-layer, BL), que són pel·lícules polimèriques amb una capa formada per nanocristalls d'un conductor orgànic. D'aquesta manera, s'obtenen films amb potencials aplicacions tecnològiques ja que mostren les mateixes propietats elèctriques que els monocristalls del conductor orgànic preservant a la vegada les propietats del polímer com són flexibilitat, transparència i baixa densitat. / This Thesis can be divided in three main parts. The first part is based on the study of the electrical properties of triads (donor-acceptor-donor) formed by one molecule of fullerene and two molecules of tetrathiafulvalenes (TTF) derivatives. Four of the most abundant isomers were separated by HPLC and were characterized by UV-Vis and HMBC RMN. The EPR spectra of the derived radical cations are identical for all the isomers and, in any of the experimental conditions used herein, no electronic transfer between the two TTF's through the different C60 fragments was observed in the mixed valence specie. On the other hand, either the semi-empiric calculations or the EPR studies of the derived radical anions show that the spin density is different in the studied isomers. This methodology could be useful for the characterization and design of new triads which could present intramolecular electronic transfers mediated by the fullerene.The second part of this Thesis consists in the synthesis and study of ionic radical salts (SIR's) of TTF derivatives which could have interesting electric and magnetic properties. Using anions of the family [Cr(NCS)4(N-donor)2]n- that can form S···S and/or p-p interactions, we showed that the latter sort of interactions are the responsible ones for the long range magnetic order observed in this kind of salts. On the other hand, taking into account the salt (DT-TTF)2Au(mnt)2, which was the first organic spin ladder, and with the aim of obtaining new organic spin ladders, new SIR were synthesized and characterized using two different strategies: i) modifying the TTF donor, ii) modifying the anionic complex. It has been seen that the approach of using the same aromatic donor DT-TTF with different anions gives better results and can give rise to other new compounds which also show spin ladder magnetic interactions.Lastly, we showed that the technique Modified Reticulate Doping Technique (MRDT) allows the preparation of bi-layer films (BL), which are polymeric films with a thin layer formed by nanocrystals of an organic conductor. Using this technique, films with potential technological applications have been prepared. These films reveal the same electrical properties ad the monocrystals of the organic conductor whilst preserving the polymer properties such as flexibility, transparency and low density.

No description available.

No description available.

Acquiring in depth knowledge of the ozone oxidation of surface-bound fullerenes advances the understanding of fullerene fate in the environment, as well as the reactivity of ozone with carbonaceous nanomaterials. Recent ultrahigh vacuum studies of the reaction of gasphase ozone with surface-bound fullerenes have made it possible to observe the formation and subsequent thermal decomposition of the primary ozonide (PO). As the use of nanomaterials, such as C₆₀, continues to increase, the exposure of these molecules to humans and the environment is of growing concern, especially if they can be chemically altered by common pollutants. These experiments are made possible by combining ultrahigh vacuum surface analysis techniques with precision dosing using a pure O₃ gas source. The experimental setup also provides the capability of monitoring surface-bound reactants and products in situ with reflection-absorption IR spectroscopy, while gas-phase products are detected with a mass spectrometer. Our results indicate that ozone adds across a 6/6 bond on the C₆₀ cage, forming an unstable intermediate, the primary ozonide. The observed initial reaction probability for the PO is γ = 4.1 x 10⁻³. Energies of activation for the formation and decomposition of the PO were obtained via temperature-dependent studies. After formation, the primary ozonide thermally decomposes into the Criegee Intermediate which can rearrange or, upon further exposure to ozone, react with another ozone molecule to form a variety of products such as carbonyls, anhydrides, esters, ethers, and ketenes. Larger fullerenes (C₇₀, C₇₆, C₇₈, and C₈₄) were also exposed to gas-phase ozone, in order to observe the reaction rate for ozonolysis and to propose an initial mechanism for ozone exposure. The results indicate that the structure of the fullerenes has little to no impact on the rate of oxidation via ozone. Lastly, Terbium endohedral were exposed to ozone, in an effort to determine whether ozone was capable of oxidizing both the outer fullerene cage, as well as the Tb atom sequestered inside. The preliminary XPS data suggests ozone oxidizes both within an hour of continuous exposure. Understanding this atmospherically-relevant reaction from both a mechanistic and kinetic standpoint will help predict the environmental fate of fullerenes and their oxides. / Ph. D.

Semicondutores orgânicos têm atraído cada vez mais atenção da comunidade científica e de indústrias. O grande interesse se divide entre a riqueza de fenômenos físicos e químicos a serem estudados e o seu grande potencial de aplicação tecnológica nas mais diversas áreas: diodos emissores de luz (OLEDs), células solares e fotodiodos, transistores, biosensores, sensores de radiação ionizante, entre outros. O objetivo deste trabalho foi de contribuir para o avanço de duas áreas de aplicação, ambas relacionadas com a interação de radiação eletromagnética com a matéria: células solares e dosimetria de radiação gama. Na área de células solares, foram explorados dois dos principais limitadores do aumento de eficiência de conversão de potência: a falta de materiais com absorção na região em que o Sol emite mais fótons (infravermelho próximo (NIR)) e a dificuldade de controle da morfologia interna das células. Foi demonstrado um novo conceito de fabricação de células solares através da nanoestruturação de filmes finos poliméricos. A metodologia de estruturação se baseia no processo de separação de fases em blendas poliméricas durante o processo de deposição por spin-coating e a subseqüente remoção de uma das componentes. Assim é possível obter uma camada ativa cobrindo todo o substrato e apresentando ondulações na superfície que podem ser variadas desde alguns nanômetros de altura e largura até micrômetros. O processo de nanoestruturação é discutido e dispositivos fotovoltaicos foram produzidos cobrindo filmes nanoestruturados de MEH-PPV com fulereno C60. A eficiência de conversão de potência destas células é três vezes maior do que o melhor resultado já reportado para este par de materiais até o momento e atinge quase 3% sob irradiação monocromática. Utilizando corantes cianinos, dispositivos fotovoltaicos e fotodiodos com resposta desde no visível até o infravermelhor próximo (~1000 nm) foram demonstrados e foi observado um papel importante dos íons móveis presentes nos corantes. Finalmente, foi demonstrada a aplicabilidade de um corante polimerizado como dosímetro de radiação gama. A faixa de operação do dosímetro pode ser alterada variando-se a concentração da solução do corante, que poderia ser utilizado na região de doses de irradiação de alimentos. / Organic semiconductors have atracted much attention from the scientific community and from the industry. The large interest is divided between the rich number of basic physical and chemical phenomena to be investigated and the great technological potential for application in different areas, such as light emitting diodes (OLEDs), solar cells, photodiodes, transistors, biosensors, ionizing radiation sensors, among others. The subject of this work was to contribute to a deeper understanding of two areas of application, both related to the interaction of electromagnetic radiation with matter: solar cells and gamma ray dosimetry. In the area of solar cells, the lack of materials absorbing in the near infrared (NIR) and the poor control of the morphology of the active films are limiting factor to increasing device efficiency. Therefore both this aspects were explored. A new concept of organic solar cell fabrication was presented based on the anostructuration of polymeric thin films. The methodology is based on phase separation of polymer blends during spin-coating followed by the selective removal of one component. This allows the controlled formation of thin films with characteristic features varying from a few nanometers to micrometers. The effects of molecular weigth, solvent and relative composition were investigated and discussed based on the analysis of AFM images and phase separation models. Devices using structured MEH-PPV layers, covered by C60 were fabricated and showed white light power conversion efficiencies (?) up to 400 % higher than a flat double layer device. Monochromatic ? achieved 2.95 % (480 nm), three times higher than the best reported value for this material combination so far. Using cyanine dyes, photovoltaic devices and photodiodes active in the NIR (~1000 nm) were demosntrated and an important effect of movable ions present in the dyes was observed. Finally, the application of a polymerized dye as gamma ray dosimeter was demonstrated. The operation range can be altered by varying the concentration of polymer in solution, and are useful in the range of low dose food irradiation.

Semicondutores orgânicos têm atraído cada vez mais atenção da comunidade científica e de indústrias. O grande interesse se divide entre a riqueza de fenômenos físicos e químicos a serem estudados e o seu grande potencial de aplicação tecnológica nas mais diversas áreas: diodos emissores de luz (OLEDs), células solares e fotodiodos, transistores, biosensores, sensores de radiação ionizante, entre outros. O objetivo deste trabalho foi de contribuir para o avanço de duas áreas de aplicação, ambas relacionadas com a interação de radiação eletromagnética com a matéria: células solares e dosimetria de radiação gama. Na área de células solares, foram explorados dois dos principais limitadores do aumento de eficiência de conversão de potência: a falta de materiais com absorção na região em que o Sol emite mais fótons (infravermelho próximo (NIR)) e a dificuldade de controle da morfologia interna das células. Foi demonstrado um novo conceito de fabricação de células solares através da nanoestruturação de filmes finos poliméricos. A metodologia de estruturação se baseia no processo de separação de fases em blendas poliméricas durante o processo de deposição por spin-coating e a subseqüente remoção de uma das componentes. Assim é possível obter uma camada ativa cobrindo todo o substrato e apresentando ondulações na superfície que podem ser variadas desde alguns nanômetros de altura e largura até micrômetros. O processo de nanoestruturação é discutido e dispositivos fotovoltaicos foram produzidos cobrindo filmes nanoestruturados de MEH-PPV com fulereno C60. A eficiência de conversão de potência destas células é três vezes maior do que o melhor resultado já reportado para este par de materiais até o momento e atinge quase 3% sob irradiação monocromática. Utilizando corantes cianinos, dispositivos fotovoltaicos e fotodiodos com resposta desde no visível até o infravermelhor próximo (~1000 nm) foram demonstrados e foi observado um papel importante dos íons móveis presentes nos corantes. Finalmente, foi demonstrada a aplicabilidade de um corante polimerizado como dosímetro de radiação gama. A faixa de operação do dosímetro pode ser alterada variando-se a concentração da solução do corante, que poderia ser utilizado na região de doses de irradiação de alimentos. / Organic semiconductors have atracted much attention from the scientific community and from the industry. The large interest is divided between the rich number of basic physical and chemical phenomena to be investigated and the great technological potential for application in different areas, such as light emitting diodes (OLEDs), solar cells, photodiodes, transistors, biosensors, ionizing radiation sensors, among others. The subject of this work was to contribute to a deeper understanding of two areas of application, both related to the interaction of electromagnetic radiation with matter: solar cells and gamma ray dosimetry. In the area of solar cells, the lack of materials absorbing in the near infrared (NIR) and the poor control of the morphology of the active films are limiting factor to increasing device efficiency. Therefore both this aspects were explored. A new concept of organic solar cell fabrication was presented based on the anostructuration of polymeric thin films. The methodology is based on phase separation of polymer blends during spin-coating followed by the selective removal of one component. This allows the controlled formation of thin films with characteristic features varying from a few nanometers to micrometers. The effects of molecular weigth, solvent and relative composition were investigated and discussed based on the analysis of AFM images and phase separation models. Devices using structured MEH-PPV layers, covered by C60 were fabricated and showed white light power conversion efficiencies (?) up to 400 % higher than a flat double layer device. Monochromatic ? achieved 2.95 % (480 nm), three times higher than the best reported value for this material combination so far. Using cyanine dyes, photovoltaic devices and photodiodes active in the NIR (~1000 nm) were demosntrated and an important effect of movable ions present in the dyes was observed. Finally, the application of a polymerized dye as gamma ray dosimeter was demonstrated. The operation range can be altered by varying the concentration of polymer in solution, and are useful in the range of low dose food irradiation.

The diploma thesis deals with the technology of production of the body of an artillery shell caliber 155 mm from C60 steel. The part is manufactured in series of 100,000 pieces. Based on a literature study and materials, a technological procedure of drop forging was designed, taking into account the specific shape of the forging. The volume of the starting blank and the forming force were determined. A suitable forming machine was selected based on the magnitude of the forming force. The design of tools for punching operations and reduction diameters of sets of rollers for forging stretching was also performed. In the technical and economic evaluation, the material costs for the production of the entire series were quantified.