Thèses sur le sujet « Fullerenoly »

Dans la chimioradiothérapie concomitante, il y a un effort pour augmenter son efficacité et atténuer la toxicité pour les cellules saines. Cela peut être atteint par le biais du synergisme et de la délivrance ciblée de médicaments (DCM). La DCM est un transport sélectif des médicaments vers des sites d'intérêt, protégeant ainsi les tissus sains de la toxicité des agents chimiothérapeutiques. Le synergisme est l'effet maximal de la chimioradiothérapie résultant des interactions complexes entre les deux modalités de traitement, comme l'interaction d'un agent radiosensibilisant avec des électrons de basse énergie (EBE) générés dans les tissus irradiés. Dans ce contexte, la thèse se concentre sur le processus de radiosensibilisation afin d'étudier le potentiel et les mécanismes radiosensibilisants des molécules sélectionnées basés sur leur interaction avec les EBE ; l'objectif est d'obtenir de nouvelles informations permettant de concevoir des radiosensibilisateurs plus efficaces et moins toxiques. La partie théorique traite des radiosensibilisateurs existants et leurs composés modèles du point de vue de l'interaction avec les EBE. La partie expérimentale combine des expériences d'attachement électronique en phase gazeuse et des calculs ab initio des affinités électroniques des molécules étudiées, des expériences de radiolyse pulsée en solution, ainsi que l'irradiation par microtron avec évaluation par la spectroscopie de résonance magnétique nucléaire. Sur la base de l'étude des interactions avec les EBE (secondaires), le potentiel radiosensibilisant a été confirmé pour l'agent antiviral favipiravir ; une interaction significative a été prouvée pour le radiosensibiliseur chimiothérapeutique RRx-001, ainsi qu'une forte interaction des électrons solvatés avec les fullerénols comme une plate-forme radiosensibilisante destinée à la DCM<br>In concomitant chemoradiotherapy (CCRT), there is an effort to increase its effectiveness and alleviate toxicity for healthy cells. It may be achieved via synergism and targeted drug delivery (TDD). TDD is the selective drug transport to sites of interest, protecting healthy tissue from chemotherapeutic toxicity. The synergism, the highest chemoradioterapeutic effect, results from complex interactions between both treatment modalities, as the interaction of the radiosensitizing chemo-drug with secondary low-energy electrons (LEEs) arising in irradiated tissue. In light of that work focuses on the radiosensitization process to investigate the radiosensitizing potential and mechanisms of selected molecules based on interaction with LEE; there is an aim to obtain new information to design more effective radiosensitizers with lower toxicity. The theoretical part deals with existing radiosensitizers and their model compounds from the point of view of interaction with LEEs. The experimental part combines electron attachment experiments in the gas phase and ab initio calculations of electron affinities of studied molecules, pulse radiolysis experiments in solution, and microtron irradiation with NMR spectroscopic evaluation. Based on the study of interaction with (secondary) LEEs, the radiosensitizing potential was confirmed for the antiviral agent favipiravir; significant interaction was proven for radiosensitizing chemotherapeutic RRx-001 as well, so as a strong interaction of solvated electrons with fullerenols as a radiosensitizing carrier drug for TGM in CCRT<br>Konkomitantní chemoradioterapie je jedna z důležitých metod léčby rakoviny. Stále existuje snaha zvýšit její účinnost a udržet toxicitu pro zdravé buňky na snesitelné úrovni. Její největší výhodou je synergický efekt plynoucí z mnoha komplexních interakcí mezi oběma léčebnými přístupy (tzn. chemoterapie a radioterapie). Bylo ukázáno, že jednou z příčin synergismu může být interakce chemosložky (tzv. radiosensitizéru) se sekundárními nízkoenergetickými elektrony vznikajícími v hojném počtu během radiolýzy v ozářené tkáni. V této práci se zaměřuji na proces radiosensitizace s cílem prozkoumat radiosensitizační potenciál molekul a odhalit radiosensitizační mechanismy na bázi jejich interakce s nízkoenergetickými elektrony. Motivací této práce bylo získat nové informace pro návrh nových a více účinných radiosensitizérů s menší toxicitou. Práce sestává z teoretické a experimentální části. Teoretická část je postavena na rešerši již existujících radiosensitizérů a jejich modelových sloučenin z pohledu interakce s nízkoenergetickými elektrony. Experimentální část kombinuje experimenty elektronového záchytu v plynné fázi na dvou experimentálních zařízeních, experimenty pulsní radiolýzy v roztoku, dále ozařování na mikrotronu s NMR spektroskopickým vyhodnocením a ab-initio výpočty elektronových afinit studovaných molekul a jejích fragmentů. V této práci bylo studováno antivirotikum favipiravir, pro který jsme na základě interakce s nízkoenergetickými elektrony potvrdili jeho radiosensitizační potenciál. Také byl zkoumán mechanismus radiosensitizace již potvrzeného radiosensitizéru a zároveň chemoterapeutika RRx-001 z pohledu jeho možné interakce se sekundárními nízkoenergetickými elektrony, která byla v této práci potvrzena. Nakonec byla odhalena silná interakce solvatovaných elektronů s fullerenoly studovanými pro použití v rámci platformy, která by prokazovala citlivost na nízkoenergetické elektrony a užívala by se pro dodávání léků v rámci konkomitantní chemoradiační terapii

Memoria para optar al título de Químico<br>Se estudiaron mezclas de tres monómeros líquidos cristalinos con fullereno: dos de ellos son azo compuestos A6OA12 y A6A12, y el tercero una imina, A11R6. No se apreció una buena miscibilidad entre dichos compuestos y fullereno utilizando técnicas de microscopia de luz polarizada y Análisis Térmico Diferencial. Un mejor resultado se obtuvo al utilizar un compósito del tipo polímero:monómero, el cual posee comportamiento antiferroeléctrico. Se obtuvieron mezclas homogéneas que fueron posteriormente dispuestas en celdas de 6,8 μm. Las celdas fueron sometidas al proceso de poling y estudiadas utilizando la técnica piroeléctrica. Las mezclas polímero:monómero con fullereno no perdieron sus propiedades antiferroeléctricas. Se observó un considerable aumento en el valor del coeficiente piroeléctrico. Este aumento se atribuye a un aumento en la absorción de luz y por tanto térmica por parte del compósito en longitudes de onda en el infrarrojo aportadas por el fullereno. Los incrementos registrados en las curvas piroeléctricas fueron más de dos veces amplificados con respecto al composito sin fullereno, a concentraciones tan baja como 2,1% en la mezcla. Es posible considerar aplicaciones de este material en sensores o para el desarrollo de celdas fotovoltaica de alta eficiencia<br>Mixtures of three liquid crystalline fullerene monomers were studied: two of them are azo compounds A6OA12 and A6A12, and the third one an imine, A11R6. Good miscibility between these fullerene and the monomeric compounds was not appreciated using techniques of polarized light microscopy and differential thermal analysis. A better result was obtained by using composite of polymer:monomer, which had been probed to exhibit antiferroelectric behavior. Homogeneous mixtures with fullerene were then arranged into cells of 6.8 microns. The cells were subjected to the poling process and studied using the pyroelectric technique. The mixtures polymer:monomer and fullerene did not lose its antiferroelectrics properties. A considerable increase in the value of the pyroelectric coefficient was observed. This increase is attributed to an increase in light absorption and thus heat in the composite provided by the fullerene inclusion at the near infrared. The pyroelectric curves were more than two times amplified compared with the composite without fullerene, at concentrations as low as 2.1% in the mixture. Applications as sensors of this material or for the development of high efficiency photovoltaic cells may be expected for these materials

Una molécula para los aficionados al fútbol (El descubrimiento de los Fullerenos y su aparición en las estampillas del Reino Unido)<br>A molecule for football fans (The discovery of fullerenes and their appearance on stamps UK)

(Base de datos de tesis doctorales TESEO) <br/><br/>En este trabajo de tesis doctoral se desarrollan básicamente dos aspectos. El primero, es la síntesis de receptores bis-porfirínicos metalados con zinc, tanto acíclicos como cíclicos, y con diferente grado de saturación de las cadenas carbonadas, y el segundo, trata sobre los estudios de complejación llevados a cabo con ligandos de diferente tipo y propiedades: aminas y fullerenos. Los primeros se unen mediante enlaces de coordinación metal-nitrógeno, mientras que los segundos se basan en interacciones &#61552;&#61485;&#61552; entre el anillo aromático de la porfirina y la estructura con un marcado carácter aromático de los fullerenos.<br/>Además, se exponen los resultados obtenidos al derivar uno de los ciclopéptidos del grupo de investigación del Prof. J.R. Granja con una o dos porfirinas de zinc y emplear el ensamblaje supramolecular tipo "sándwich" entre bis-porfirinas y aminas ditópicas para controlar la mezcla regioisomérica que tiene lugar en el proceso de autoensamblaje entre los ciclopéptidos.<br>(Base de datos de tesis doctorales TESEO) English version<br/><br/>In this doctoral thesis two main aspects are developed. The first is the synthesis of bis-porphyrin receptors metallated with zinc, both acyclic and cyclic, and with different degrees of saturation of the carbon chain, and the second deals with the studies of complexation with ligands of different types and properties: amines and fullerenes. The first ligands are connected by metal-nitrogen coordination between the nitrogen of the ligand and the zinc of the porphyrin ring, while the latter are &#61552; &#61485; &#61552; interactions between the aromatic ring of the porphyrin and the fullerenes.<br/>In addition, we present the results obtained when derive one of the cyclopeptides of the research group of Prof. J.R. Granja with one or two zinc porphyrins, using the motif: "sandwich" complexes between bis-porphyrins and ditopic amines, in order to control the regioisomeric mixture that takes place in the self-assembly of the cyclopeptides.

U radu je predstavljena sinteza i karakterizacija&nbsp; novog fulerenol/doksorubicin nanokompozita, sintetisanog sa ciljem dobijanja potencijalne nove nanoformulacije postojećeg antineoplastika doksorubicina, koja bi pokazala veću biolo&scaron;ku aktivnost uz smanjenje neželjenih sporednih efekata koje sam lek izaziva, na prvom mestu kardiotoksičnosti.Nanokompozit fulerenol/doksorbicin je okarakterisan brojnim&nbsp; metodama prateći dva osnovna eksperimentalna pristupa: molekulsko-spektroskopske metode (XPS, denzitometrija i transportne osobine, NMR, UPLC, Ramanska i UV-spektroskopija, SFM) i metode&nbsp; nanokarakterizacije (DLS, AFM, TEM), kao i računske simulacije(RDF). Osnovni cilj ispitivanja je bila detekcija postojanja&nbsp;nekovalentnog nanokompozita koji ostvaruju doksorubicin i fulerenolske nanočestice u vodenom rastvoru. Rezultati karakterizacije jasno i nedvosmisleno ukazuju na postojanje nekovalentnih interakcija unutar nanokompozita, &scaron;to dalje utiče na organizaciju i udruživanje čestica, a &scaron;to uslovljava i drugačiju biolo&scaron;ku aktivnost takvog sistema u odnosu na pojedinačne komponente.&nbsp; Rezultati biolo&scaron;kih ispitivanja na&nbsp;<em>in vitro</em>&nbsp;modelu različitih tumorskih ćelijskih linija pokazuju&nbsp; značajan&nbsp;antiproliferativni efekat nanokompozita, kao i selektivnost prema tumorskim u odnosu na zdravu ćelijsku liniju. Eksperimenti na <em>in vivo</em> modelu zebrica potvrđuju smanjenje toksičnosti nanokompozita u poređenju sa lekom, primarno kardiotoksičnosti. Računske simulacije, mikroskopski i spektroskopski podaci, kao i rezultati&nbsp; <em>in vitro</em> i <em>in vivo</em> studija ukazuju na to da nekovalentne interakcije između fulerenola i doksorubicina mogu biti ključni korak u stvaranju sinergističkog sistema za dostavu leka u biolo&scaron;ki sistem.Multipotentnost fulerenola kao nanonosača lekova i nespecifičnost strukture doksorubicina kao leka, ukazuje na to da bi fulerenol mogao biti efikasan nanonosač i drugih antineoplastika, &scaron;to daje prostora za unapređenje antitumorskih osobina lekova posredstvom istovremene administracije leka.<br>The focus of this thesis was the synthesis and characterization of a novel fullerenol/doxorubicin nanocomposite, with the aim to obtain a potential nanoformulation of antineoplastic drug doxorubicin, which would&nbsp; express greater biological activity and lower level of adverse effects than the drug itself, in the first place cardiotoxicity.Nanocomposite fullerenol/doxorubicin was characterized by means of numerous methods&nbsp; following two main experimental approaches: molecular-spectroscopic methods (XPS, densitometry and transport properties, NMR, UPLC, Raman and UVspectroscopy, SFM) and mehods of&nbsp; anocharacterisation&nbsp; (DLS, AFM,&nbsp; TEM), as well as computer simulations (RDF). The goal of characterization was detection of&nbsp; non-covalent interactions within nanocomposite that are established between fullerenol nanoparticles and doxorubicin in aqueous solution. The results clearly indicate the existence of non- covalent interactions within nanocomposite that affect the organization and assembling of the particles, which further exhibit different biological activity of such a system in comparison to components themselves. Results of biological activity on <em>in vitro </em>model of different tumor cell lines show significant antiproliferative effect of&nbsp; nanocomposite, as well as selectivity towards tumor cell lines. Experiments conducted on <em>in vivo</em> zebrafish model confirm the lowering ofthe adverse effects of the drug, especially cardiotoxicity, in case when nanocomposite was applied. Computer simulations, microscopic and&nbsp; spectroscopic results combined with encouraging <em>in vitro </em>and <em>in vivo</em> results point out&nbsp; that non-covalent interactions between fullerenol nanoparticles and doxorubicin may present the keyrole in formation of a synergistic system for nanodrug delivery into biological system. Multipotential of fullerenol nanoparticles as a nanocarrier and non-specific structure of doxorubicin as a drug imply that fullerenol may serve as a efficient nanocarrier of numerous other antineoplastics, which further allows the improvement of antitumor properties of drugs withsimultaneous drug administration.

Aquesta tesis doctoral està dividida en dues parts. La primera part de la tesi inclou el disseny, la síntesi i caracterització d’una sèrie de receptors trimèrics de porfirines així com l’estudi de la formació de complexes d’inclusió amb ful•lerens (C60, C70, C84, Sc3N@C80), nanotubs de carboni (CNT) i bucky onions. L’objectiu principal d’aquest primer bloc és la preparació de receptors de porfirines capaços de formar, de manera selectiva o preferent, complexos d’inclusió amb ful•lerens grans (>C84) així com carbon nano onions (CNOs) i nanotubs de carboni (CNT). En la segona part de la tesi, es detalla la síntesi i estudi de un monòmer piramidal amb estructura central de CTV quiral connectada a llargues cadenes alquíliques a través d’enllaços d’urea. L’objectiu principal d’aquest segon bloc és la preparació d’un monòmer de CTV capaç d’ampliar tal quiralitat del monòmer a l’estructura supramolecular. Per tal de promoure aquest comportament, els monòmers van ser previstos de urees que degut a la seva habilitat per establir ponts d’hidrogen d’especificitat i direccionalitat alta promourien la formació d’una hèlix macroscòpica.<br>Esta tesis doctoral está dividida en dos partes. La primera parte de la tesis incluye el diseño, síntesis y caracterización de una serie de receptores trimericos de porfirinas así como el estudio de la formación de complejos de inclusión con fulerenos (C60, C70, C84, Sc3N@C80), nanotubos de carbono (CNT) y bucky onions. El objetivo principal de este primer bloque es la preparación de los receptores de porfirinas capaces de formar de manera selectiva o preferente, complejos de inclusión con fulerenos grandes (>C84) así como carbon nano onions (CNOs) y nanotubos de carbono (CNT). En la segunda parte de la tesi se detalla la síntesis y estudio de un monómero piramidal con estructura central de CTV quiral conectada a largas cadenas alquílicas a través de enlaces tipo urea. El objetivo principal de este segundo bloque es la preparación de un monómero capaz de ampliar tal quiralidad a la estructura supramolecular. Para promover tal comportamiento, los monómeros son provistos de ureas que debido a su habilidad para establecer puentes de hidrogeno de alta especificidad y direcctionalidad promoverian la formación de una hélice macroscópica.<br>This thesis is divided in two different parts. The first part includes the design, synthesis and characterization of a series of porphyrin trimeric receptors as well as the study of the inclusion complex formation with fullerenes (C60, C70, C84, Sc3N@C80), carbon nanotubes (CNT) and bucky onions. The main objective of this first bloc is the preparation of porphyrin-based receptors able to selectively encapsulate big fullerenes (>C84) as well as carbon nano onions (CNOs) and carbonnanotubes (CNT). The second part of the thesis deals with the synthesis and studies of a chiral pyramidic monomer bearing a CTV central core connected to long alkyl chains through urea type linkers. The objective of this second block would be the preparation of a CTV-monomer able to transfer the chirality from the CTV central core to the supramolecular column. To promote such behavior, the monomers are provided with urea moieties that due to their high specificity and directionality would promote de formation of the macroscopic helix.

En los últimos años ha surgido una nueva tecnología en el rango nanométrico denominado hoy en día Nanotecnología. Desde su descubrimiento, la producción y uso de nanomateriales se ha visto incrementado rápidamente. Uno de ellos es el Fulereno (C60), el cual es utilizado en diferentes campos de la ciencia y la tecnología como la medicina, cosmética, electricidad, entre otros. Esta nueva industria genera desechos de producción que tienen como destino final los ambientes acuáticos, del mismo modo los residuos del uso de productos que contienen nanomateriales como los son algunos detergentes, bloqueadores solares, desodorantes. Como es sabido los ambientes acuáticos son dinámicos y conformados por múltiples componentes. Sin embargo, no se han realizado suficientes evaluaciones de los posibles efectos de la exposición de dicho compuesto en el ambiente y por ende, en los organismos, más aún, la interacción del mismo con otros contaminantes de origen natural o artificial. El presente estudio fue realizado con el fin de evaluar la influencia de un nanocompuesto denominado Fulereno (C60) sobre un organismo acuático denominado Daphnia magna, mediado por dos factores adicionales: un metal (Cobre) y la luz ultravioleta en condiciones de laboratorio. Para ello, se obtuvieron “dafnias” que posteriormente fueron reproducidas considerando 16h luz/ 8h oscuridad y una alimentación en base a Nutrafiin basic (3g) suplementado con levadura (0.05g). Luego del cultivo, se sometió a los organismos juveniles de Daphnia magna, a diferentes tratamientos durante 48 hrs., luego de los cuales se evaluó lo siguiente: 1) DL50 y la EC50 en diferentes concentraciones de Fulereno (C60) y Cobre; 2) El grado de estrés oxidativo generado por una gradiente de concentraciones de Fulereno (C60) y Cobre; 3) Evaluar su comportamiento considerando la frecuencia de saltos por minuto ante la exposición a diferentes concentraciones y bajo la influencia de luz UV (pre y post); y, 4) Evaluar la producción de melaninas como respuesta a la exposición de Fulereno C60 y Cobre a diferentes concentraciones y bajo la influencia de luz UV (pre y post). Esto permitió estimar el riesgo ambiental del fulereno aunado a contaminantes clásicos como un metal (Cobre) y la luz UV, a fin de proponer posibles mecanismos de acción. Los resultados muestran que no hay diferencias estadísticamente significativas en cuanto a capacidad antioxidante entre un pre y post tratamiento con luz UV-Vis, sin embargo sí existen diferencias a nivel comportamental (frecuencia de saltos) y entre la cantidad de melaninas generadas entre ambos tratamientos considerando la mezcla de Fulereno C60 y Cobre, y la pre y post exposición a radiación UV.<br>In recent years there has emerged a new technology in the nanometer range today called Nanotechnology. Since its discovery, production and use of nanomaterials has been increased rapidly. One is the Fullerene (C60), which is used in different fields of science and technology such as medicine, cosmetics, electricity, among others. This new industry generates waste production are destined for aquatic environments, just as the use of waste products containing nanomaterials as are some detergents, sunscreens, deodorants. As is well known aquatic environments are dynamic and shaped by multiple components. However, there have been sufficient assessments of the potential effects of exposure to this compound in the environment and therefore, in organisms, even more, its interaction with other pollutants of natural or artificial origin. This study was conducted in order to evaluate the influence of a nanocomposite called Fullerene (C60) on a water body called Daphnia magna, mediated by two other factors: a metal (copper) and the ultraviolet light in the laboratory. To do this, “daphnia” which were subsequently reproduced considering 16h light / 8h dark and feeding based on basic Nutrafiin (3g) supplemented with yeast (0.05g) was obtained. After the culture was subjected to youth organizations Daphnia magna, to different treatments for 48 h, after which the following were evaluated: 1) LD50 and EC50 in different concentrations of Fullerene (C60) and Copper; 2) The degree of oxidative stress generated by a concentration gradient of fullerene (C60) and Copper; 3) Assess their behavior considering the frequency of jumps per minute when exposed to different concentrations and under the influence of UV light (pre and post); and 4) Evaluate the production of melanin in response to exposure of fullerene C60 and copper at different concentrations and under the influence of UV light (pre and post). This allowed us to estimate the environmental risk of fullerene contaminants coupled with classics like a metal (copper) and UV light in order to propose possible mechanisms of action. The results show no statistically significant differences in antioxidant capacity between before and after treatment with UV -Vis light, however there are differences at the behavioral level (frequency hopping) and between the amount of melanin generated between both treatments considering fullerene C60 mixture and Copper, and pre and post exposure to UV radiation. Keywords: Fullerene (C60), Copper, antioxidant capacity, frequency jumps, Melanin.<br>Tesis

Aquesta Tesi titulada ‘Computations on Fullerenes: Characterization, Reactivity and Growth’ es focalitza amb els mecanismes de formació i caracterització de ful·lerens prèviament detectats als experiments. Són caixes tancades de carboni formades per hexàgons i dotze pentàgons. Hem col·laborat amb diferents grups experimentals, per tant, ens hem centrat en entendre i racionalitzar els seus experiments. Diferents models de formació de ful·lerens han estat proposats, però encara avui segueix sent un misteri. Els nostres estudis donen completament suport al mecanisme de creixement bottom-up proposat pel Prof. Kroto. Aquest mecanisme ha estat estudiat per càlculs estàtics de DFT i per dinàmica molecular de Car-Parrinello. Una exploració exhaustiva dels isòmers més favorables, així com les superfícies d’energia potencial associades a les insercions d’unitats C2 als ful·lerens i les topologies de les estructures involucrades, han ajudat al desenvolupament d’aquest projecte. Aquest procés d’inserció és exotèrmic/exergònic, i encara que les barreres d’energia lliure són elevades, es poden veure superades a la temperatura de formació de ful·lerens (2000 K). Els isòmers més abundants del Ti@C2n (2n=26-48) i Sc3N@C2n (2n=68-80) s’han relacionat mitjançant unitats C2 i, en alguns casos, alguna isomerització del tipus Stone-Wales. Respecte a la detecció i aïllament dels metal·loful·lerens endoèdrics, ens hem centrat en la seva caracterització. La cloració dels ful·lerens també ha estat estudiada, ja que ha sorgit com una poderosa eina en el món dels derivats de ful·lerens. Famílies de C2n (2n=50,60,66,68,etc.) han estat trobades com cloroful·lerens. Els nostres resultats prediuen que la cloració s’esdevé un cop es formada la caixa neutra a temperatures més baixes de 2000 K, mitjançant l’addició de radical lliure i tenint en compte les distribucions del HOMO i de la densitat d’spin. La majoria dels nostres projectes han estat d’acord amb els resultats experimentals.<br>La Tesis titulada ‘Computations on Fullerenes: Characterization, Reactivity and Growth’ se focaliza con los mecanismos de formación y caracteritzación de fullerenos previamente detectados a los experimentos. Son cajas cerradas de carbono formadas por hexágonos y doce pentágonos. Hemos colaborado con diferentes grupos experimentales, por tanto, nos hemos centrado en entender y racionalizar sus experimentos. Diferentes modelos de formación han sido propuestos, pero todavía hoy sigue siendo un misterio. Nuestros estudios dan soporte al mecanismo de crecimiento bottom-up propuesto por el Prof. Kroto. Este mecanismo ha sido estudiado mediante cálculos estáticos de DFT i por dinámica molecular de Car-Parrinello. Una exploración exhaustiva de los isómeros más favorables, así como las superficies de energía potencial asociadas a las inserciones de unidades C2 a los fullerenos y las topologías de las estructures involucradas, han ayudado al desarrollo de este proyecto. Este proceso de inserción es exotérmico/exergónico, y todavía que las barreras de energía libre son elevadas, se pueden ver superadas a la temperatura de formación de fullerenos (2000 K). Los isómeros más abundantes del Ti@C2n (2n=26-48) y Sc3N@C2n (2n=68-80) se han relacionado mediante unidades C2 y, en algunos casos, alguna isomerización del tipo Stone-Wales. Respecto a la detección y aislamiento de los metallofullerenos endoédricos, nos hemos centrado en su caracteritzación. La cloración de los fullerenos también ha sido estudiada, ya que ha surgido como una poderosa herramienta en el mundo de los derivados de fullerenos. Familias de C2n (2n=50,60,66,68,etc.) han sido encontradas como clorofullerenos. Nuestros resultados predicen que la cloración se forma una vez es formada la caja neutra a temperaturas más bajas de 2000 K, mediante la adición de radical libre y teniendo en cuenta las distribuciones del HOMO y de la densidad de espín. La mayoría de nuestros proyectos han estado de acuerdo con los resultados experimentales.<br>The Thesis titled ‘Computations on Fullerenes: Characterization, Reactivity and Growth’ is mainly focused on the formation mechanisms and characterization of fullerenes previously detected in experiments. These molecules are closed carbon cages formed by only hexagons and twelve pentagons. Most part of our research has been carried out in collaboration with different experimental groups, therefore we aimed to understand and rationalize their experiments. Although many hypothetical models have been proposed, the fullerene formation mechanism is still a mystery. Our studies rules out the bottom-up mechanism as a model of fullerene formation. We have explored this mechanism by means of static DFT and Car-Parrinello molecular dynamics calculations for series of different endohedral fullerenes. A comprehensive exploration of the most favourable isomers, potential energy surfaces associated with the successive C2 insertions and topologies of the involved structures, helped us to develop this project. The insertion of a C2 unit to already formed EMF is always an exothermic/exergonic process, and the free energy barriers for each step are attainable at temperature of fullerene formation (2000 K). The most abundant isomers of Ti@C2n (2n=26-48) and Sc3N@C2n (2n=68-80) are formally linked by direct C2 insertions and in a few cases by additional Stone-Wales transformations. Regarding the detection and isolation of endohedral metallofullerenes let us to perform a computational study of the rationalization and characterization of these isomers. Chlorination has emerged as a powerful tool in fullerene derivatives. Several C2n families (2n=50,60,66,68,etc.) have been found to show cages exohedrally chlorinated. According to our results, chlorination would take place at a temperature significantly lower than 2000 K by free radical addition considering the HOMO and the spin density distributions of the pristine cage and intermediates, once the lowest energy neutral isomers are formed. Most of our projects resulted in suitable and in agreement with experiments.

Nesta tese foram perseguidos novos avanços no campo das tetrapiridilporfirazinas supramoleculares polimetaladas, visando explorar a maior capacidade de conjugação eletrônica esperada para essa classe de compostos, e seus reflexos nas propriedades eletrônicas e eletroquímicas. Foram apresentadas novas rotas sintéticas para obtenção de tetra(3,4-piridil)porfirazinas centrometaladas coordenadas a complexos polipiridínicos de rutênio, MTRPyPz (M = Cu, Co). As propriedades espectroscópicas e eletroquímicas foram investigadas com o auxílio de técnicas de espectroscopia UV-Vis, Raman ressonante, voltametria cíclica, espectroeletroquímica e espectrometria de massas. Foram desenvolvidas aplicações em dispositivos amperométricos para determinação eletrocatalítica de substratos importantes nas indústrias, como nitrito, sulfito e ácido ascórbico. Os estudos também abrangeram a formação de compósitos das porfirazinas tetrarrutenadas com fullereno. Os nanomateriais híbridos apresentaram uma alta eficiência nos processos eletrocatalíticos com menor sobrepotencial no eletrodo, abrindo perspectivas interessantes de utilização em dispositivos moleculares<br>Research in supramolecular polymetallic tetrapyridylporphyrazines has been pursued in this Thesis, aiming the exploitation of the favorable electronic delocalization associated with conjugated aromatic rings, and its influence on the electronic and electrochemical properties. New synthetic routes have been developed for the preparation of tetra(3,4-pyridyl)porphyrazines containing Cu(II) and Co(II) ions in the center, and four chlorobis(2,2´bipyridine)ruthenium(II) complexes attached to the peripheral pyridyl groups. Their spectroscopic and electrochemical behaviors were investigated by means of UV-Vis and resonance Raman spectroscopy, cyclic voltammetry, spectroelectrochemistry and mass spectrometry. Applications in amperometric devices for determination of nitrite, sulfite and ascorbic acid were successfully developed. The thesis also focused on nanocomposites generated from the polymetallic porphyrazines and fullerene (C60). Such hybrid nanomaterials exhibited enhanced electrocatalytic activity associates with a significant decrease of overpotential, opening exciting perspectives of use in molecular devices

Des del descobriment del buckminster ful.lerè el 1985, s'ha despertat un interés enorme per entendre la reactivitat química així com les propietats d'aquests compostos. La funcionalització exoèdrica del ful.lerè més abundant, el C60, està força ben establerta. Tanmateix, la investigació en aquest camp encara continua oberta ja que s'han sintetitzat una gran varietat de derivats molt prometedors donades les seves futures aplicacions. La tesi comprèn quinze capítols que contenen set publicacions relacionades. Els primers dos estudis es basen en la reacció Diels-Alder sobre els anomenats metal.loful.lerens endoèdrics TNT X3N@C78, X= Sc, Y. Aquest projecte de investigació està motivat pel desconeixament existent sobre les possibles conseqüències de l'encapsulació del grup X3N. El tercer estudi descriu minuciosament els canvis detectats en la funcionalització exoèdrica un cop s'ha produït l'encapsulació dels diferents gasos nobles. En aquesta tesi s'estudia en detall l'ús de l'aproximació ONIOM per a estudiar reaccions de cicloaddició en compostos ful.lerènics. Els resultats d'aquest projecte són d'alt interès per a la realització dels estudis posteriors sobre la reacció de Diels-Alder i la 1,3-dipolar en ful.lerens i derivats. Finalment, l'última part d'aquesta tesi es basa en les propietats antioxidants de determinats ful.lerens. A l'últim treball inclòs en aquesta tesi s'estudia en detall el mecanismo de reacció per a la eliminació del ió superòxid en presència de ful.lerens.<br>Since the buckminster fullerene discovery in 1985, a huge interest for understanding the chemical reactivity as well as the chemical properties of fullerene compounds has been awakened. The exohedral functionalization of the archetypal compound C60 is nowadays considered to be quite well-established. Still, the research in this field is open as a wide variety of derivatives with intriguing potential applications have been synthesized. The thesis is divided into fifteen chapters that contain seven related publications. The first two studies are based on the Diels-Alder reaction involving the Trimetallic Nitride Template (TNT) endohedral metallofullerenes X3N@C78, X = Sc, Y . This investigation project was basically motivated by the unclear evidence about the possible consequences of the X3N. The third study thoroughly describes the change on the exohedral functionalization upon noble gas encapsulation. In the fourth study included in this thesis, the performance of the ONIOM approach for studying cycloaddition reactions involving fullerene compounds is studied in detail. Results from the latter project are of interest for the following studies involving the 1,3-dipolar and the Diels-Alder cycloaddition reactions where the ONIOM strategy is employed. Finally, the last part of this thesis is based on the antioxidant properties of fullerene compounds, where the mechanism of action for the superoxide removal involving fullerene compounds is unraveled. The understanding of the SOD removal mechanism could represent a big improvement to design new fullerene derivatives with higher antioxidant properties.

Des del seu descobriment, a la molècula C60 se li coneixen una varietat de derivats segons el tipus de funcionalització amb propietats fisicoquímiques específiques de gran interès científic. Una sel·lecció de derivats corresponents a addicions simple o múltiple al C60 s'ha considerat en aquest treball d'investigació. L'estudi a nivell de química computacional de diversos tipus d'addició al C60 s'han portat a terme per tal de poder donar resposta a aspectes que experimentalment no s'entenen o són poc clars.<br/>Els sistemes estudiats en referència a l'addició simple al C60 han estat en primer lloc els monoiminoful·lerens, C60NR, (de les dues vies proposades per la seva síntesi, anàlisis cinètic i termodinàmic han ajudat a explicar els mecanismes de formació i justificar l'addició a enllaços tipus [5,6]), i en segon lloc els metanoful·lerens i els hidroful·lerens substituits, C60CHR i C60HR, (raons geomètriques, electròniques, energètiques i magnètiques justifiquen el diferent caràcter àcid ente ambdós derivats tenint en compte una sèrie de substituents R amb diferent caràcter electrònic donor/acceptor). Els fluoroful·lerens, C60Fn, i els epoxid ful·lerens, C60On, (anàlisi sistemàtic dels seus patrons d'addició en base a poder justificar la força que els governa han aportat dades complementàries a les poques que existeixen experimentalment al respecte).<br>Since the discovery of C60 molecule a large number of derivatives molecules have been described with a great scientific interest of their specific physical and chemical properties. A selection of single and multiple addition products has been considered in this investigation. Study at Computational Chemistry level for this selected derivatives have been carried out in order to give answer to several points that experimentally are not understandable or not enough clear.<br/>As single addition derivatives, firstly were studied the monoiminofullerenes, C60NR, (two routes of synthesis have been considered, kinetic and thermodynamic analysis have help to explain formation mechanisms and justify the possible addition at [5,6]-type bonds), and secondly the methanofullerenes and the substituted hydrofullerenes, C60CHR and C60HR, (geometric, electronic, energetic and magnetic reasons justify the different acid character between both series of derivatives taking care on the influence of R substituents with different donor/acceptor character). The fluorofullerenes, C60Fn, and the epoxide fullerenes, C60On, have been studied as multiple addition derivatives (systematic analysis of the addition pattern have been performed in the way to find reasons to justify the driving force of the multiple addition process).

Fullerenes are a group of spherical molecules with outstanding 2/1 physicochemical properties that make them important materials in a variety of fields, ranging from biomedicine to photovoltaics. However, in order to become useful molecules, fullerenes have to be previously modified. In this sense, since the early days of fullerene science, organic chemists have managed to prepare a plethora of fullerene derivatives by employing different synthetic strategies. On the other hand, transition metal-catalyzed cyclization reactions provide a powerful synthetic tool to access molecular complexity with high efficiency and selectivity. The works developed in the context of this doctoral thesis deal with the development of Rh(I)-catalyzed cyclization reactions directed to the functionalization of fullerene C60. Moreover, the mechanism of the processes described has been extensively studied by quantum chemical calculations and some of the prepared products have been used as electron-transporting materials in perovskite solar cells<br>Els ful·lerens constitueixen un grup de molècules esfèriques que presenten un seguit de propietats que els converteixen en materials d&#39;interès en diversos camps com la medicina o la generació d&#39;energia fotovoltaica. No obstant això, per convertir-se en molècules útils, l&#39;estructura química dels ful·lerens ha de ser prèviament modificada.En aquest sentit, els ful·lerens poden ser funcionalitzats mitjançant diferents estratègies sintètiques. D&#39;altra banda, les reaccions de ciclació catalitzades per metalls de transició proporcionen una potent eina sintètica per accedir a molècules d&#39;elevada complexitat de forma eficient i selectiva. La major part dels treballs desenvolupats en el context d&#39;aquesta tesi doctoral tracten sobre el desenvolupament de reaccions de ciclació catalitzades per complexes de rodi(I) dirigides a la funcionalització del ful·lerè C60. El mecanisme dels processos descrits ha estat estudiat mitjançant càlculs de química quàntica i alguns dels productes preparats s&#39;han utilitzat com a materials transportadors d’electrons en cèl·les fotovoltaiques de tipus perovskita

Nanotechnology is the multidisciplinary science consisting in modifying the matter at the nanometre scale. Due to the unique properties exhibited by nanomaterials, the number of investigations devoted to obtain new materials and their applications has increased dramatically. However, the potential risk associated to nanomaterials and nanostructures continues being poorly understood. Different gaps of information were identified including their environmental occurrence, fate, behaviour and toxicity. In addition, some nanomaterials can also be emitted by natural events or incidental sources. Under this context, this doctoral Thesis presents the study of the occurrence and toxicity of nanomaterials and nanostructures in the environment, focusing on pristine and functionalized fullerenes and volatile dimethylsiloxanes. Different extraction procedures for the analysis of pristine and functionalized fullerenes in different environmental compartments were developed: (i) For the investigation of their occurrence in air particulate two extraction procedures are presented, based on ultrasound assisted solvent extraction with toluene with recoveries from 60 to 70 %, and using accelerated solvent extraction with recoveries ranging from the 70 to 113 %; (ii) for the investigation of soils using a long-term ultrasound assisted solvent extraction with toluene; (iii) for the simultaneous analysis of fullerenes in the particulate and dissolved phases of water samples. Two analytical methods based on liquid chromatography coupled to mass spectrometry for the analysis of fullerenes in environmental samples were developed. The first one employed C18 analytical column with toluene:methanol as mobile phase and an ESI source in negative ionization conditions coupled to a triple quadrupole analyzer. The second method consisted in the use of pyrenylpropyl stationary phase columns with toluene as mobile phase. LC was coupled to HRMS with an APPI source. The main improvements of the second approach were in terms of lower matrix effect, better sensibility and selectivity. The occurrence of pristine and non-polar functionalized fullerenes was evaluated in several compartments. - Air particulate: The concentrations of C60 ranged from 10 pg/m3 to 50 ng/m3 in the Mediterranean Sea atmosphere, and between the MLOQ and 63 pg/m3 in air particulate of Barcelona city. - Soils: Samples were taken in Saudi Arabia and Brazil, close to potential emission points. The concentrations of pristine fullerenes were in the pg/g–ng/g levels, showing the incidental emission these compounds and subsequent deposition. - Freshwater and sediments from the Llobregat River. The relationship between the occurrence of natural colloids and the sedimentation of fullerenes because of heteroaggregation and flocculation was studied. Pristine fullerenes were detected in all the compartments while functionalized fullerenes were detected very rarely. The results show that incidental combustion sources are the main contributor to the environment, in contrast to nanotechnology. The occurrence of siloxanes was studied in several environmental compartments. According to our results the intensive manufacture and application of cVMS such as in personal care products, industry, nano-emulsions, etc. lead to the emission of these compounds at global-scale: - Wastewater: Siloxanes were detected in almost all influent and effluent samples at concentrations up to 24 µg/L. In general, for VMS relevant elimination rates during WW treatments were shown. - Fish: Fish directly sampled in the Xúquer River and fish for human consumption collected in different markets stores were analysed. Market fish presented higher levels, which can be attributed to contamination during food manipulation, storage and ambient air. - Samples from the Antarctic region: VMS were found in all types of the analyzed samples (krill, phytoplankton, soil and vegetation). These results reveal for first time the potential long-range environmental transport of VMS and their posterior cool-deposition supported by the snow scavenging during winter time and their posterior liberation to sea water and soils during the Antarctic summer. The acute toxicity of carbon nanomaterials (fullerene soot, carbon nanotubs and graphene) dispersed in artificial estuary medium in ecologically relevant conditions was studied using two standardized acute toxicity tests. The results are to fullerenes aggregation in presence of humic acid and salts. The presence of fullerene soot is relevant because inhibited the activity of most of the organic co-contaminants due to their sorption properties.<br>El desenvolupament de la nanotecnologia ha generat una miríada de nous materials que, sumats als nanomaterials presents de forma natural al medi ambient, generen un seguit d’incerteses. La present tesi va tenir l’objectiu de contribuir en l’estudi d’aquests nanomaterials i nanoestructures determinant la presència de ful·lerens i siloxans de mida nanomètrica en el medi ambient. Es van desenvolupar mètodes d’anàlisi per a ful·lerens en diverses matrius ambientals: particulat atmosfèric, sòls, sediments, aigües de riu i de depuradora. Per al seu anàlisi instrumental, es van desenvolupar dos mètodes. El primer, basat en cromatografia de líquids amb columnes de fase estacionària C18 i fase mòbil toluè-metanol, acoblada a espectrometria de masses en tàndem amb font d’electrosprai. El segon mètode, basat en cromatografia de líquid amb columna de fase estacionària de pirenilrpopil i toluè com a fase mòbil, acoblada a espectrometria de masses d’alta resolució amb font de fotoionització a pressió atmosfèrica. La segona metodologia millorava les prestacions de la primera en termes d’efecte matriu, selectivitat i sensibilitat. Es va determinar la presència de ful·lerens en particulat atmosfèric, sòls i sediments i aigua de riu. Es van detectar ful·lerens no funcionalitzats a nivells traça en la majoria de mostres, podent-se localitzar fonts d’emissió. Els ful·lerens funcionalitzats es van detectar esporàdicament, demostrant la preponderància dels processos accidentals en front de la nanotecnologia. Es van analitzar els siloxans en diversos compartiments ambientals. Els resultats d’aquesta tesi demostren com l’ús intensiu d’aquests compostos en productes domèstics, aplicacions industrials, nano-emulsions, etc, contribueix a la seva emissió al medi ambient a escala global. Es van detectar siloxans en totes les mostres d’aigües residuals analitzades, en mostres de peix de mercat i de riu i en mostres remotes de l’Antàrtida. Es va modelitzar la seva deposició. Finalment es va estudiar la toxicitat aguda de tres nanomaterials de carboni (pols de ful·lerens, nanotubs de carboni i grafè) dispersos en medi artificial d’estuari i en condicions ecològicament rellevants. Es van emprar dos tests estandarditzats de toxicitat aguda i es va determinar que la toxicitat dels agregats resultants ve determinada per la presència d’àcids húmics i salinitat del medi. També es va observar com la presència de pols de ful·lerè inhibia l’activitat d’altres co-contaminants orgànics presents en el medi.

It all started in 1985, when Kroto, Smalley and Curl discovered by serendipity a new carbon allotrope. They synthesized for the first time the C60 molecule, and named it as ”Buckminsterfullerene”, because of the similarity between its structure and the famous geodesic dome designed by the architect Richard Buckminster Fuller. An interesting type of fullerenes are the so-called endohedral (metallo)fullerenes, which are fullerenes containing atoms, small molecules or metallic clusters inside. A huge interest in this new class of molecules has been awakened mainly due to their potential applications in many different fields, for example in (bio)medicine as a magnetic resonance imaging contrast agents, or in photovoltaics as a new and more efficient dye sensitized solar cells. To that end, it is essential to know and understand their chemical structure and reactivity to ensure their use for (bio)medical purposes and to modify their properties to develop new fullerene-based technology devices or biomaterials. In this thesis the chemical structure and reactivity of endohedral (metallo)fullerenes is studied in detail using state-of-the-art computational tools<br>Al 1985, Kroto, Curl i Smalley van sintetitzar per primera vegada la molècula C60, i la van anomenar ”Buckminsterful·lerè” degut a la similitud entre la seva estructura i la famosa cúpula geodèsica dissenyada per l’arquitecte Richard Buckminster Fuller. Un tipus de ful·lerens molt interessants són els anomenats (metalo)ful·lerens endohèdrics, que són aquells que contenen àtoms, molècules petites o agregats metàl·lics encapusulats al seu interior. Des del seu descobriment s’ha despertat un enorme interès en aquestes molècules degut a les seves potencials aplicacions en camps molt diferents, com per exemple en (bio)medicina per al seu ús com a agents de contrast en imatge per ressonància magnètica, o en el camp de l’energia fotovoltaica per a la fabricació de noves cèl·lules solars. Per aquesta raó, és imprescindible conèixer i entendre la seva estructura i reactivitat química per tal de garantir el seu ús amb finalitats (bio)mèdiques i per modificar les seves propietats per desenvolupar nous (bio)materials basats en ful·lerens. En aquesta tesi, l’estructura química i la reactivitat dels (metalo)ful·lerens endohèdrics s’estudien en detall utilitzant les eines de la química computacional

The main goal of this work is to introduce new carbon structures - carbon nanotubes. The main objective of this work is to take advantage of the unique characteristic of carbon nanotubes to emit electrons at very low supply voltage.

Given the existing problem of Climate Change, we must work towards more environmentally friendly chemical processes that would help us solve it. The thesis focuses on the study of different chemical reactions involved in the production of hydrogen for use as fuel, as well as the optimization of industrial processes to reduce unwanted products and thus, improve the efficiency of the reaction. In addition, it deals with the recycling of dinitrogen monoxide and carbon dioxide to lighten the planetary load, and the study of the reactivity of carbon nano-onions as a basis for the construction of more efficient solar panels<br>Dado el problema existente del Cambio Climático, debemos hacer un esfuerzo para hacer procesos químicos más amigables con el medioambiente que nos ayuden a resolverlo. La tesis se centra en el estudio de diferentes reacciones químicas involucradas en la producción de hidrógeno para usarlo como combustible, así como la optimización de procesos industriales para reducir los productos no deseados y mejorar así la eficiencia de la reacción. Además, se trata el reciclado de monóxido de dinitrógeno y dióxido de carbono para aligerar la carga planetaria, y el estudio de la reactividad de las nano-cebollas de carbono como base para la construcción de placas solares más eficientes<br>Programa de Doctorat en Química

The interest in the detail knowledge about elementary electronic processes during photogeneration of charge carriers, which allow achieving higher efficiency of organic solar cells, grows with advent of the commercial organic solar cells production. The thesis is focused on study of photogeneration of charge carriers in organic semiconductors, especially in -conjugated polymer materials. First part of the thesis summarized state of the art in studies of photogeneration of charge carriers in polymer solar cells. Subsequent experimental and results part are focused on study of polymeric solar cells prepared from electron donor polymers MDMO-PPV, Tg-PPV, PCDTBT and PCBTDPP and electron acceptor derivates of fullerenes PC60BM and PC70BM. Results of the thesis are divided in tree main parts: 1) study of charge transfer between electron donor and electron acceptor materials by optical methods, 2) study of charge transfer between electron donor and electron acceptor materials by optoelectrical methods and 3) development of organic solar cells on flexible substrates. The last part is focused largely on deposition methods of active materials thin layer.

The physical and chemical properties of fullerenes and nanotubes can be conveniently tuned by the attachment of different functional groups to them. Therefore, the systematic understanding of different problems such as chemical reactivity, catalysis, and even charge transfer can be achieved. In the current thesis, these challenges are faced transcending in interesting outcomes. That is to say, the covalent junction between chemical species and carbon nanostructures are explained in detail, thus providing a characterization of the experimentally observed products. In a second part of the thesis, the role of fullerene C60 in chemical reactions catalyzed by transition metals is elucidated. Finally, the potential applications of derivatives of fullerene C60 in the design of solar cells are illustrated. The thesis is widely supported by quantum chemistry methodology and conclusions were corroborated through experimental evidence<br>Les propietats físiques i químiques dels ful·lerens i nanotubs poden ser convenientment modificades mitjançant la unió de diferents grups funcionals. Per tant, és possible aconseguir la comprensió sistemàtica de diferents problemes com ara la reactivitat química, catàlisi, i fins i tot de transferència de càrrega. A la tesi actual, aquests reptes s'afronten donant lloc a resultats interessants. És a dir, la unió covalent entre espècies químiques i nanoestructures de carboni s'expliquen detalladament, proporcionant així una caracterització dels productes observats experimentalment. En una segona part de la tesi, es descriu el paper de ful·lerè C60 en les reaccions químiques catalitzades per metalls de transició. Finalment, s'il·lustren les aplicacions potencials dels derivats de ful·lerè C60 en el disseny de cèl·lules solars. La tesi és àmpliament fonamentada per metodologia de la química quàntica i les conclusions van ser corroborades a través d'evidències experimentals

Diploma thesis is focused on the study of optoelectric properties of thin layers of organic materials based on phthalocyanines, which can be used as an active layer of photovoltaic cells. Especially are studied the properties of the thin active layers of PdPc and PdPc + IL on the glass or ceramic substrates with aluminium contact, which are prepared by material printing here. On the prepared samples were first measured current-voltage characteristics in the dark and in the light and then were measured impedance spectrums in the dark. The received results will be used to improve the properties and structures of photovoltaic cells.

The first exhaustive purification and characterization of fullerenol samples, prepared by reaction of C60 in toluene with NaOH solution using tetrabutylammonium hydroxide as a phase transfer catalyst, have been performed. The resulting fullerenol was determined to have a molecular formula of Na+n[C60Ox(OH) y]n- (where n = 2--3, x = 7--9, and y = 12--15 for three different, but identical, preparations). The Na +-fullerenol was found to contain both hemiketal moieties (6--8 per fullerenol) and a carbonyl moiety (1 per fullerenol) by an X-ray photoelectron spectroscopy study. In addition, Na+-fullerenol was found to be anionic with an average negative charge of 2--3 and a molar conductance in water in the range of 174--297 cm-1mol -1O-1 at 25&deg;C. Surprisingly, the Na+-fullerenol is also paramagnetic exhibiting mueffective values in aqueous solution of 1.9--2.1 B.M. at 0.5 T and 300 K and R1 proton relaxivities of 0.55--0.77 mM-1s-1 at 20 MHz and 40&deg;C, values both slightly higher than those expected for a pure S = &frac12; spin system. In solid state SQUID measurements, the Na+-fullerenols had mueffective values of ca. 1.3 B.M. (300K). ESR studies of frozen aqueous solutions at 1.5 and 5.0 K established that Na+-fullerenol is mainly S = &frac12; with a minor, but significant, concentration of S = 1. Thus, this is the first report to characterize the widely-studied, water-soluble fullerenols as radical anion species. The Na+-fullerenol paramagnetism was partially quenched by the addition of acid, but was reversed upon addition of base. This acid/base chemistry can be used to partition a Na+-fullerenol sample into less paramagnetic and more paramagnetic fullerenol species, with the more paramagnetic species having more S = 1 character. It is hypothesized that the paramagnetic character of Na+-fullerenol results from the formation of cyclopentadienyl radical centers on the fullerene cage, formed by an oxidation reaction with atmospheric oxygen. Sodium ions in Na+-fullerenol can be ion exchanged for other cations (e.g. Ba2+, H+, tetrabutylammonium cation, and protonated meglumine) producing fullerenols with varying magnetic and spectroscopic properties. Finally, paramagnetic Na+-fullerenol (110 mg/kg) has been shown to serve in vivo as a magnetic resonance imaging (MRI) contrast agent in a rat model, although, the rat did not survive the experiment.

Doxorubicin (DOX) is an important anthracycline antineoplastic drug used to treat a variety of cancers. As well as other antineoplastic agents, DOX has negative side effects; the most serious one is cardiotoxicity. Conjugation of DOX with nanomaterials could help to reduce its adverse effects. The presented thesis entitled ,,Nanomaterials as a platform for the DOX transport -- Fluorescence imaging" is primarily focused on the study of DOX interaction with biomolecules such as amino acids and albumin. The interaction was analysed by fluorescence spectrometry and by other analytical methods and significant interaction with amino acids as well as with protein albumin was detected. Next work was focused on the utilization of nanoparticles in DOX transport. DOX was conjugated with fullerenes or encapsulated in liposomes and properties of these nanoconstructs, in vitro and in vivo, were analysed. Both of these nanomaterials seemed to be good nanotransporters for DOX targeted delivery.

Tese de Doutoramento em Ciência e Engenharia de Polímeros e Compósitos<br>Organic photovoltaics (OPVs) have experienced significant developments in power conversion efficiency (PCE), attaining recently over 16 % for small area single junction devices. Aiming to bring the OPV technology to market, much efforts are being made to further improve their efficiencies and the development of novel fullerenes and the improvement of the active layer morphology (ex: additives, annealing) are some of the strategies currently being pursued. In this thesis, 16 novel N-methyl-fulleropyrrolidine acceptors, based on the fullerenes C60 (8) and C70 (8), were synthesized (Prato reaction). The functionalization of C70 yields a mixture of 4 regioisomers that have different HOMO/LUMO levels as determined by DFT calculations. The sixteen fullerene derivatives were tested in bulk-heterojunction (BHJ) solar cells with the low bandgap polymer PffBT4T-2OD. The different pendant groups attached to the N-methylfulleropyrrolidines consisted of phenyl groups (Chapter II) and thiophene and carbazole groups (Chapter III). For both sets, the corresponding HOMO/LUMO energy levels were determined by cyclic voltammetry. Even though several of the synthesized fulleropyrrolidine acceptors have more favorable (higher) LUMO levels than the standard PC71BM, when tested in PffBT4T-2OD based solar cells they originate devices with lower performances than reference devices based on PC71BM. Additionally, devices based on C60-fulleropyrrolidines show in general better photovoltaic performances than the corresponding devices based on C70-fulleropyrrolidines (structural and energetic disorder introduced by the regiosomer mixture of C70 derivatives) . The effect of different additives on the morphology and performance of PffBT4T-2OD:PC71BM based OPVs is investigated in Chapter IV. Some additives possess antagonist effects: some are shown to improve the PCE; others decrease PCE by ~30% and others eliminate any PCE. Grazing- Incidence Wide-Angle X-ray Scattering (GIWAXS) reveals a clear stepwise variation in the crystallinity of the systems when changing the additive between the two extreme-situations of maximum PCE (1-chloronaphthalene) and PCE null (hexadecane). Small Angle Neutron Scattering (SANS) reveals that the morphology of devices with PCE ~0% is composed of large phase domains with correlation lengths ~30 nm, i.e. much larger than the typical exciton diffusion length in organic semiconductors.<br>A energia fotovoltaica orgânica (OPVs) tem vivenciado desenvolvimentos significativos na eficiência de conversão de energia (PCE), atingindo recentemente mais de 16% para dispositivos de junção única de área pequena. Com o objetivo de trazer a tecnologia OPV ao mercado, estão sendo feitos muitos esforços para melhorar ainda mais suas eficiências e o desenvolvimento de novos fulerenos e o aprimoramento da morfologia da camada ativa (por ex: aditivos, recozimento) são algumas das estratégias atualmente adotadas. Nesta tese, 16 novos aceitadores de N-metil-fulleropirrolidina, com base nos fulerenos C60 (8) e C70 (8), foram sintetizados (reação de Prato). A funcionalização do C70 produz uma mistura de 4 regioisômeros que têm níveis diferentes de HOMO / LUMO, conforme determinado pelos cálculos de DFT. Os 16 derivados de fulereno foram testados em células solares BHJ com o polímero de baixo intervalo de banda PffBT4T-2OD. Os diferentes grupos pendentes ligados às N-metilfulleropirrolidinas consistiram em grupos fenil (capítulo II) e grupos tiofeno e carbazol (capítulo III). Para ambos os conjuntos, os níveis de energia HOMO / LUMO correspondentes foram determinados por voltametria cíclica. Embora vários dos aceitadores de fulleropyrrolidina sintetizados tenham níveis LUMO mais favoráveis (mais altos) do que o PC71BM padrão, quando testados em células solares baseadas em PffBT4T-2OD, eles originam dispositivos com desempenho mais baixo do que os dispositivos de referência baseados no PC71BM. Além disso, os dispositivos baseados em C60-fulleropirrolidinas apresentam, em geral, melhores desempenhos fotovoltaicos do que os dispositivos correspondentes baseados em C70-fulleropyrrolidinas (desordem estrutural e energética introduzida pela mistura de regiosômeros dos derivados C70). O efeito de diferentes aditivos na morfologia e desempenho dos OPVs baseados em PffBT4T- 2OD: PC71BM é investigado no Capítulo IV. Alguns aditivos possuem efeitos antagonistas: alguns melhoram o PCE; outros diminuem o PCE em ~ 30% e outros eliminam qualquer PCE. A dispersão de raios-X de ângulo amplo de incidência rasante (GIWAXS) revela uma clara variação gradual na cristalinidade dos sistemas ao alterar o aditivo entre as duas situações extremas de PCE máximo (1-cloronaftaleno) e PCE nulo (hexadecano). A dispersão de neutrões a baixos angulos (SANS) revela que a morfologia de dispositivos com PCE ~ 0% é composta por grandes domínios de fase com comprimentos de correlação ~ 30 nm, ou seja, muito maiores que o comprimento típico de difusão do excitão em semicondutores orgânicos.