Neste trabalho analisou-se por ressonância magnética nuclear em baixa (RMN-BR) e em alta resolução (RMN-AR), compostos de coordenação contendo íons paramagnéticos em solução. Demonstrou-se que estas são importantes ferramentas para o estudo destas espécies em meio aquoso, visando aplicações tanto em química analítica quanto em química inorgânica e bioinorgânica. Os estudos iniciais foram realizados com o ligante EDTA (Y4-), clássico agente quelante, e seus complexos com os íons Cu2+, Fe3+ e Mn2+. Os resultados demonstraram que a RMN-BR (20 MHz para o 1H) torna-se uma eficiente alternativa à espectrofotometria, principalmente para o estudo de complexos que não absorvem radiação no visível, como por exemplo, o quelato [Mn-Y]2-. A relaxometria por RMN-BR também foi usada para estudar soluções de quitosana (Chi) e seus complexos com os mesmos íons paramagnéticos previamente abordados para o EDTA. Os resultados demonstraram a eficiência da relaxometria tanto para os estudos de agregação polimérica em função do pH quanto para os estudos de complexação.<a name=\"_Hlk488851348\"> Foram também abordados complexos de sorbitol com íons Cu2+ tanto por relaxometria quanto por RMN-AR (600 MHz para o 1H). Neste caso, os resultados apresentaram uma alta complementariedade, permitindo inferir tanto acerca da troca de ligantes em solução e do pH ótimo para a complexação, quanto do surgimento de espécies macromoleculares com baixos coeficientes de autodifusão (D &asymp; 1,58 x10-10 mm2.s-1) em meio alcalino (pH &asymp; 12). Além do mais, foram avaliados novos complexos de Gd3+ com relevância biológica (agentes de contrastes), derivados do ligante AAZTA (6-amino-6-metilperhidro-1,4-diazepina). Os resultados demonstraram que as relaxividades paramagnéticas (r1p) foram de 7,44 mM-1.s-1 e 9,41 mM-1.s-1 para os derivados funcionalizados lateralmente com os ácidos propanoico e pentanoico, respectivamente, em comparação ao ligante precursor, 7,10 mM-1.s-1. Os estudos relaxométricos in vitro mostraram que estes novos derivados são menos susceptíveis à transmetalação com íons endógenos (Zn2+ e Ca2+), quando comparado ao AAZTA, possibilitando projetar o seu uso como agentes de contraste em tomografia por ressonância magnética (MRI). Aplicações relaxométricas in vivo foram realizadas utilizando o derivado contendo o ácido pentanoico conjugado ao peptídeo FibPep, apto a se ligar à proteína fibrina (presente em células tumorais). Os resultados demonstraram uma alta habilidade deste complexo para o assinalamento precoce e inequívoco do câncer de próstata (linhagem tumoral PC-3) em camundongos. / Low-resolution (LR) and high-resolution (HR) nuclear magnetic resonance (NMR) was used in this work for study coordination compounds containing paramagnetic ions in solution. It was demonstrated that these spectroscopies are important tools for the study of these species in aqueous medium, aiming applications in both, analytical chemistry and inorganic and bioinorganic chemistry. The initial studies were conducted using the EDTA (Y4-) ligand, classical complexant, and its chelate with the paramagnetic ions, among them Cu2+, Fe3+ and Mn2+. The results demonstrated that LR-NMR (20 MHz to 1H) becomes an efficient alternative to spectrophotometry, mainly for the study of complexes that do not absorb visible radiation, such as [Mn-Y]2- chelate. The LR-NMR relaxometry was also used to study chitosan (Chi) solutions and their complexes with the same paramagnetic ions previously discussed for EDTA. The results demonstrated the efficiency of the relaxometry for studies involving complexation and polymer aggregation as a function of the pH. Complexes of sorbitol with cupric ions were also addressed by relaxometry and HR-NMR (600 MHz to 1H). In this case, the results showed a high complementarity, allowing to infer about the ligand exchange and the optimum pH for the complexation reaction occurs. Besides, this study showed the appearance of species with low auto diffusion coefficients (D &asymp; 1.58 x10-10 mm2.s-1) in alkaline mediums (pH &asymp; 12), as consequence of the macromolecular character of this complex in this environment. In addition, new biologically relevant Gd3+ complexes (contrast agents) derived from AAZTA (6-amino-6-methylperhydro-1,4-diazepine) ligand were evaluated. The results demonstrated that the paramagnetic relaxivities (r1p) were 7.44 mM-1.s-1 and 9.41 mM-1.s-1 for derivatives laterally functionalized with propanoic and pentanoic acids, respectively, in comparison to precursor ligand, 7.10 mM-1.s-1. In vitro relaxometric studies demonstrated that these new derivatives are less susceptible to transmetallation reactions towards to endogenous ions (Zn2+ and Ca2+), in comparison to AAZTA (precursor ligand), becoming possible to design their use as contrast agents in magnetic resonance imaging (MRI) tomography applications. In vivo studies were conducted using the pentanoic acid derivative conjugated to FibPep peptide, able to bind to fibrin protein (present in tumor cells). The results for this study demonstrated a high ability of this complex for the early and unequivocal signaling for prostate cancer (PC-3 tumoral cell line) in mice.

Os eletrólitos poliméricos sólidos têm sido alvo de estudos devido às suas diversas aplicações em baterias e dispositivos eletrocrômicos. O material que estudamos é composto por amilopectina, um dos principais componentes do amido, polimerizado com glicerol, que forma filmes. Quando dopamos esse material com sal de lítio, LiClO4, ele se comporta como um eletrólito polimérico sólido, condutor iônico de lítio (&#963; &#8776; 3x105 S/cm a 300K). Nesse trabalho apresentaremos o estudo desse material utilizando técnicas de Ressonância Magnética Nuclear (RMN) nos núcleos H e 7Li. Fizemos medidas da largura de linha e do tempo de relaxação spin-rede (T11) em função da temperatura (183K a 393K) com o objetivo de obter informações tanto sobre a dinâmica iônica, através da ressonância do 7Li, como sobre a dinâmica dos prótons existentes na cadeia polimérica e do plasticizante através da ressonância do 1H. Os resultados das medidas de relaxação do 7Li mostram a presença de um máximo em T1-1 a temperatura de &#8776; 320k. Nosso estudo mostra que o mecanismo de relaxação dominante para o 7Li é a interação entre o momento quadrupolar do 7Li e as flutuações dos gradientes de campo elétrico produzidos pelas distribuições de carga no sítio do núcleo. A energia de ativação para o processo de difusão do lítio é Ea &#8776 0.19eV, e o tempo de correlação à temperatura ambiente é &#964; &#8776; 1.6x10-9s, que indica uma mobilidade do lítio superior às observadas em eletrólitos poliméricos com base de PEO e com base de PEO-hidroxietilcelulose, mas comparáveis às observadas em eletrólitos poliméricos com plasticizante / Solid polymer electrolytes have been studied due to his several applications in batteries and electrochromic devices. The material studied is a thermoplastic material that was obtained from amylopectin rich starch plasticized with glycerol. When doped with lithium salt, LiClO4, this material has the property to form films and it can be used as a solid polymer electrolyte, lithium ionic conductor (&#963; &#8776; 3x105 S/cm a 300K). In this work, we report H e 7Li. nuclear magnetic resonance (NMR) measurements as a function of temperature in a series of amylopectin films. Measurements of lineshapes and spin-lattice relaxation times (T11) as a function of temperature (183K - 393K) were used to obtain information about ionic motion (7Li resonance) and polymer chain dynamics (1H) in polymer electrolytes. The results of 7Li spin-lattice relaxation show a maximum T1-1 at around &#8776; 320k. Our study shows that the 7Li dominant relaxation mechanism is the interaction between quadrupolar moment of 7Li and the fluctuations of the electric field gradient produced by the charge distributions on the nucleus site. The activation energy for the lithium diffusion process is Ea &#8776 0.19eV, and the correlation time at room temperature is &#964; &#8776; 1.6x10-9s. That indicates a lithium mobility greater than the observed in polymer electrolytes based on PEO and on PEO-hidroxiethilcelulose, but comparable to the ones observed in solid polymer electrolyte

Foram realizadas pesquisas em uma série de condutores iônicos que apresentam aplicações na área dos dispositivos eletroquímicos de estado sólido, utilizando-se basicamente a técnica de Ressonância Magnética Nuclear (RMN). A primeira parte deste trabalho é dedicada aos compostos de intercalação baseados na matriz de dissulfeto de molibdênio (MoS2) onde as espécies intercalantes (íons de lítio e moléculas de aminas) são inseridas num espaço de dimensionalidade reduzida gerado pela matriz. Já a segunda parte envolve os condutores iônicos poliméricos do tipo compósitos, nos quais foram utilizadas nanopartículas de carbono (Carbon Black) e titânio (TiO2) no eletrólito formado pelo poli(óxido de etileno) (POE) e o perclorato de lítio (LiClO4). Todos estes sistemas apresentam, em geral, uma considerável complexidade estrutural, o que significa que os movimentos moleculares e de difusão iônica se produzem num meio semicristalino (caso dos compósitos) ou num meio de dimensionalidade reduzida (caso dos intercalados). A espectroscopia de RMN dos núcleos de 7Li e 1H é uma técnica conveniente para o estudo destes materiais, pois é possível avaliar, através dos resultados obtidos das medidas dos tempos de relaxação e formas de linha, os efeitos provocados pela baixa dimensionalidade dos movimentos em estruturas laminares (caso dos intercalados), bem como identificar e aferir as interações e os mecanismos de relaxação resultantes dos diferentes graus de liberdade dos movimentos (iônicos e moleculares), fornecer parâmetros estruturais (distâncias interatômicas) que auxiliam na proposta de possíveis modelos estruturais e caracterizar completamente a escala temporal dos movimentos iônicos e moleculares. / Nuclear Magnetic Resonance (RMN) techniques were used to study a series of ionic conductor materials, which present applications in the area of the solid-state electrochemical devices. The first part of this work is dedicated to the study of intercalation compounds based on the molybdenum disulfide matrix (MoS2), where the intercalated species (lithium ion and amine molecule) are inserted in the low-dimensionality space generated by the matrix. The second part involves the study of a composite polymer electrolyte, employing fillers like Carbon Black and titanium dioxide (Tio2) nano particles in the electrolyte formed by the poly(ethy1ene oxide) and a lithium salt (LiClO4). In general, these systems present a considerable structural complexity, meaning that the molecular movements and ionic diffusion are produced in a semicrystalline environment (case of the composites) or in an environment of reduced dimensionality (case of intercalates). The 7Li and 1H NMR spectroscopy is a convenient technique for the study of these materials. Relaxation time and line shape measurements may provide a tool to investigate the effects provoked by the low-dimensionality of the movements in laminate structures (case of intercalate), to identify the interactions and relaxation mechanisms of the ionic and molecular motions, to supply structural parameters (interatomic distances) that would help the proposal of possible structural models, and finally, to characterize the time scale of the ionic and molecular movements completely.

Demonstrou-se nesta tese a potencialidade da ressonância magnética nuclear no domínio do tempo (RMN-DT) para medir a temperatura de sementes oleaginosas isoladas e inseridas em solos. Os métodos desenvolvidos baseiam-se na correlação entre o tempo de relaxação do óleo das sementes com a temperatura. As medidas com o tempo de relaxação transversal, T2, foram realizadas com a sequência Carr-Purcell-Meiboom-Gill (CPMG) e as medidas de relaxação T*, com a sequência de pulsos Precessão Livre em Onda Contínua (CP-CWFP). Tanto o T2 quanto o T* apresentaram uma correlação exponencial crescente com a temperatura, utilizando espectrômetros de bancada. Com a medida do decaimento da temperatura de sementes e solos, previamente aquecidos a 70&deg;C, em um banho térmico a 23&deg;C, pode-se calcular a difusividade térmica de sementes e sementes em solos, obtendo valores similares aos obtidos com métodos padrões. Para ímãs com homogeneidade muito baixa, com gradientes de campo magnético maiores do que 1 T/m (ímãs de campos opostos, Unilateral e Halback) somente a sequência CPMG pode ser usada. A sequência CP-CWFP não gerou um sinal de onda contínua, necessário para a medida de T*. No ímã unilateral a correlação exponencial entre o decaimento do sinal CPMG e temperatura foi decrescente devido ao efeito da difusão molecular na refocalização dos ecos. Com isso a RMN unilateral, que detecta o sinal da amostra fora do sensor de RMN (ímã e sonda) tem potencial para análise da temperatura e difusividade térmica em campo. A grande vantagem da RMN sobre os métodos de termometria baseado em termômetros de mercúrio, termopares, termistores, etc., é que é um método que não precisa danificar as sementes para inserção do agente sensível à temperatura. Além disso, a RMN pode ser usada para medir a temperatura da semente, mesmo quando esta está sob uma camada de vários centímetros de solos, o que não ocorre com o sensor de Infravermelho, por exemplo. / The potential of time domain nuclear magnetic resonance (TD-NMR) to measure the temperature of isolated oilseeds and oilseeds inserted into soil was demonstrated in this thesis. The methods were based on the correlation between relaxation time of the oilseeds with temperature. The measurement with the transverse relaxation time, T2, was performed with the Carr - Purcell - Meiboom - Gill (CPMG) pulse sequence. The measurement of decay T*, was performed with the Continuous Wave Free Precession (CP- CWFP) pulse sequence. Both the T2 as T* showed an exponentially correlation with temperature using bench top spectrometers. With the measurement of the temperature decay of seeds and soils, previously heated to 70&deg;C and placed in a bath at 23&deg;C, was used to calculate the thermal diffusivity of seeds and seeds in soil. The results were similar to those obtained with standard methods. For the magnets with very low homogeneity, with strong magnetic field gradients 1 T/m (Opposite field, Unilateral and Halback magnets) only the CPMG pulse sequence could be used. The CP-CWFP sequence do not generated a continuous wave signal, necessary for the measurement of T*. The unilateral magnet shows an upward-sloping exponential curve between the decay of the CPMG signal and temperature due to the effect of molecular diffusion, in refocusing echoes. Therefore, the unilateral NMR, which detects the signal from the sample outside the NMR sensor (magnet and probe), has the potential to analyze the temperature and thermal diffusivity in the field. The big advantage of NMR over thermometry methods based on mercury thermometers, thermocouples, thermistors, etc., is that it is a method that does not need to damage the seeds for insertion of the sensor. In addition, NMR can be used to measure the seed temperature, even when it is under a layer of several centimeters of soil, which does not occur with the infrared sensor, for example.

Completely inorganic nanoscale clusters play an essential role in many aspects of inorganic chemistry, materials chemistry, and geochemistry. The underlying dynamic behavior of these species in solution defines how and why they make successful thin film precursors as well as exist naturally in the environment. There have been a limited number of previous solution studies involving inorganic nanoscale clusters due to the lack of spectroscopic handles and availability of analytical techniques. This dissertation outlines the available and appropriate characterization techniques needed for identifying and studying inorganic nanoscale species and then uses proton Nuclear Magnetic Resonance (1H-NMR) and Diffusion Ordered Spectroscopy (DOSY) to fully characterize the Ga13-xInx(µ3-OH)6(µ-OH)18(H2O)24(NO3)15 (0 ≤ x ≤ 6) cluster series in solution. This research lays a foundation for a multitude of future studies on the dynamic behavior of these species that was previously unachievable. This dissertation includes previously published and unpublished co-authored material.

The halogen bond has recently risen in prominence as a non-covalent interaction for use in supramolecular chemistry, allowing for the rational design of materials, pharmaceuticals, and functional molecules. The occurrence of the σ-hole opposite to the C-X covalent bond (X = F, Cl, Br, I) renders the halogen bond a highly directional and tuneable interaction, offering desirable features to crystal engineers. The halogen bond can be divided into its two components: the halogen bond donor bearing the halogen atom, and the electron-rich halogen bond acceptor. In this thesis, we investigate the nature of the halogen bond, its role in supramolecular assembly and impact on the local dynamics, along with developing synthetic methods to prepare this class of materials. We begin by fully characterizing the halogen bond donor by using 35Cl ultra-wideline solid-state nuclear magnetic resonance (NMR) spectroscopy on a series of single-component chloronitriles exhibiting the C-Cl···N halogen bond. We then perform the first modern nuclear quadrupole resonance (NQR) investigations of the halogen bond, observing the 79/81Br and 127I nuclei in a series of cocrystals exhibiting the C-Br···N and C-I···N halogen bond, respectively. Computational results attribute the observed increases in the quadrupolar coupling constants (CQ) to a reduction in the carbon-halogen σ-bonding contribution to V33 and an increase in the lone-pair and core orbital contributions, providing the first model of the electronic changes occurring on the halogen bond donor upon the formation of the halogen bond. Attention is then turned on characterizing the halogen bond acceptor and its surrounding environment, beginning by investigating a solid-state NMR approach relying on the 19F nucleus to characterize perfluorinated cocrystals. This strategy has reduced analysis times from hours to minutes while providing higher sensitivity and resolution, with the resulting chemical shifts permitting the unambiguous identification of the halogen bond and allowing for the refinement of X-ray crystal structures. The halogen bond acceptor is then investigated in a series of isomorphous dimers exhibiting both the halogen bond and hydrogen bond in the C≡C-I···X-···H-N+ motif, revealing the halogen bond’s relative contribution to the electric field gradient increasing in the order of Cl- > Br- > I-, contrasting the contributions of the hydrogen bond. We then explore the impact of the halogen bond on the surrounding environment, using the rotating methyl groups of 2,3,5,6-tetramethylpyrazine as a model. Upon the introduction of a halogen bond, we observe a reduction in the rotational energy barrier of 56% on average, overshadowing the 36% reduction observed in the hydrogen bonded cocrystals. This is the first instance of the halogen bond directly catalyzing the local dynamics, coining the term “dynamics catalyst”. These results provide an effective strategy of enhancing the dynamics in molecular systems, such as molecular machines, supramolecular catalyst, as well as correcting the faulty dynamics encountered in diseased proteins. The role of halogen bonding in crystal engineering is then explored, reporting the first supramolecular triangle, a series of discrete charged dimers, and supramolecular architectures built from 1,3,5-tri(iodoethynyl)-2,4,6-trifluorobenzene, with the potential of creating fully organic porous structures for gas absorption. Mechanochemistry is then investigated as a synthetic method, allowing for the preparation of cocrystals featuring 3-iodoethynylbenzoic acid as the donor, with the resulting structures exhibiting concurrent halogen and hydrogen bonding. Mechanochemical ball milling is shown to reduce preparation times of powdered cocrystals from days to a single hour, while using a fraction of the organic solvent. Lastly, we pioneer cosublimation as a solvent-free synthetic technique for rapidly preparing halogen bonded cocrystals, yielding quality single crystals within a few hours, and a microcrystalline product within 15 minutes. Among its advantages, cosublimation offers a significant acceleration of discovery, while eliminating the environmental footprint associated with conventional synthetic methods.

Foram estudados compósitos poluméricos e vidros fluoroindatos utilizando as espectroscopias de Ressonância Magnética Nuclear (RMN) pulsada e Ressonância Paramagnética Eletrônica (RPE). O estudo de RMN do 1H nos compósitos baseado no polímero polióxido de etileno e partículas de carbono permitiu diferenciar as mobilidades das cadeias poluméricas e identificar as contribuições destas fases. A partir das medidas de RPE foi possível sugerir uma interpretação das interações entre as partículas de carbono nos compósitos. Nos vidros fluoroindatos foi estudado o processo de cristalização, sendo acompanhada sua influência na relaxação nuclear do 19F. A cristalização foi observada por RPE nos vidros dopados com Cu2+, Mn2+ e Gd3+, sendo verificadas as alterações locais causadas por este processo. / Polymeric composites and fluoroindate glasses were studied using pulsed Nuclear Magnetic Resonance (NMR) and Electron Paramagnetic Resonance (EPR) spectroscopies. Study of the composite formed by the polymer poly-ethylene oxide and carbon particles allowed us to distinguish the mobilities of polimeric chains and to identify the contributions from different phases. From EPR measurements it was possible to suggest an interpretation of the interactions between carbon particles in the composites. The main objective in the fluoroindate glasses study was to follow the crystallzation process. The 19F NMR measurements allowed to the observation of the influence of this process in the nuclear relaxation. The crystallization was also tracked by EPR spectroscopy in the doped glasses with the paramagnetic ions Cu2+, Mn2+ and Gd3+. This was accomplished by observing the local alterations caused by that process.

Standard catalyst characterisation techniques such as gas adsorption porosimetry and mercury porosimetry only account for some of the physical heterogeneity of the catalyst surface. They completely ignore the chemical heterogeneity present and in most cases consider pores present in the medium to be independent of each other. Thus, most results of characterisation (pore space descriptors such as BET surface area, BJH pore size distribution, mercury porosimetry surface area, etc.) are not accurate. This has been a major issue that remains to be resolved during the characterisation of fresh and coked catalysts. In this thesis, the use of a multi-component adsorption system is recommended as a step-change solution to this limitation. Two approaches are adopted. Firstly, integrated nitrogen-waternitrogen gas adsorption experiments are performed on fresh and coked catalysts. This established the significance of pore coupling by showing the presence of advanced adsorption. The method also helped to determine the location of coke deposits within catalysts and indicated that water vapour adsorption was a good probe to understand the sites responsible for coking. Secondly, coadsorption of immiscible liquids – cyclohexane and water – was performed on fresh and coked catalysts following which the displacement of cyclohexane by water was studied using NMR relaxometry and diffusometry. This novel approach takes the wettability of the surface into consideration, unlike the former methods. It is therefore a method that accounts for the chemical heterogeneity of the surface. It also helped determine the location of coke within catalysts. The different approaches are presented in the context of combustion of heavy oil in bitumen reservoirs, and the use of supercritical conditions that help to dissolve coke precursors in the isomerisation of 1-hexene. Thus, the solutions provided in this thesis are directions in which catalyst characterisation, especially distinguishing fresh and coked catalysts, and other porous materials, must be carried out.

Membrane proteins are important targets that represent more than 50% of current drug targets. However, characterisation of membrane proteins falls behind compared to their soluble counterparts. The most challenging part of membrane protein research is finding a suitable membrane mimetic that stabilises them in solution and maintains their native structure and function. The recently developed saposin-A (SapA) based lipid nanoparticle system seems to be advantageous over existing membrane mimetic system. It provides a native-like lipid bilayer, high incorporation yield and more importantly size adaptability. SapA lipid nanoparticles have been applied to structural studies and two high-resolution structures of membrane proteins were previously obtained using cryo-electron microscopy. This thesis aimed to study small-to-medium sized membrane proteins in SapA lipid nanoparticles using NMR spectroscopy. We first explore the mechanism of SapA lipid nanoparticle formation for the purpose of establishing an incorporation protocol that can be applied to most membrane proteins. The effect of pH and the presence of detergents on the opening of SapA was investigated in Chapter 2. A proposed energy diagram describing the mechanism of SapA opening is reported with which we were able to develop a protocol that can generate different sizes of SapA-1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) nanoparticles. In addition, we also showed that SapA can form lipid nanoparticles with various lipid compositions, showing the versatility of the system. In Chapter 3, we validated the ability of SapA lipid nanoparticles to be used as a membrane mimetic. A -barrel model protein, bacterial outer membrane protein X (OmpX), was incorporated into SapA-DMPC nanoparticles and a 2D 15N-1H correlation NMR spectrum was recorded. Our result was compared to the NMR parameters of the same protein in MSP nanodiscs from the literature, and it was concluded that SapA lipid nanoparticles indeed provide a lipid bilayer environment similar to MSP nanodiscs. Because of high incorporation yield, we were able to incorporate OmpX into different lipid compositions to investigate the effect of lipid head groups and aliphatic chains on the membrane protein's chemical environment. Next, the applicability of SapA lipid nanoparticles was expanded to -helical transmembrane proteins in Chapter 4. Two microbial rhodopsins, Anabaena sensory rhodopsin (ASR) and Natronomonas pharaonis sensory rhodopsin II (pSRII), were tested. The parameters for expression and purification of ASR were first screened for the optimal yield. Although incorporation of ASR resulted in inhomogeneous particles due to imperfect experimental procedure, pSRII in SapA-DMPC nanoparticles showed high sample quality. The 2D NMR spectrum of pSRII in SapA-DMPC nanoparticles shows distinct differences to pSRII in detergent micelles, suggesting substantial effects from the membrane mimetic on the conformation of the membrane protein. Despite the good NMR spectral quality considering the large particle size, perdeuteration of pSRII and the lipids will be necessary for further investigation. With the SapA lipid nanoparticles established, we aimed to use it for the study of a biologically important G protein-coupled receptor, 1-adrenergic receptor (1AR), discussed in Chapter 5. The possibility of expressing 1AR using a cell-free expression system was explored first. Although a good amount of the protein was obtained, only a fraction of it was functional. Therefore, a conventional baculovirus-insect cell expression system was used to produce selective isotope labelled 1AR for NMR studies. NMR spectra of 1AR in SapA-DMPC nanoparticles with activating ligands and an intracellular binding partner were recorded and compared to the spectra of the same protein in detergents. This revealed a more active-like conformation of ligand-bound 1AR in the lipid bilayer, suggesting that certain parts of the protein are sensitive to the membrane mimetic used. This emphasises the importance of using a native-like membrane mimetic to capture the full properties of membrane proteins. In conclusion, I demonstrate in this thesis that SapA lipid nanoparticles are a versatile membrane mimetic system that can accommodate membrane proteins with different sizes and folds. This system is also compatible with solution NMR spectroscopy enabling structure and dynamics studies of biologically important membrane proteins. We believe SapA lipid nanoparticles will have a significant impact on membrane protein research in the future.

Novos materiais poliméricos foram desenvolvidos utilizando como uma das matérias-primas o óleo de palma (OP). Para tanto, um novo monômero de norborneno, denominado norbornenil óleo de palma (NOP), foi obtido a partir da inserção de norborneno substituído com grupo carboxílico nos triglicerídeos do óleo da palma. O óleo de palma, assim como os produtos de cada etapa de síntese do NOP foram caracterizados por RMN-1H. Foi determinado um teor de 52% de ácidos graxos insaturados no OP, resultando no NOP com 1,0 norborneno por triglicerídeo. Reações de ROMP de NOP com norborneno, na presença de catalisador de Grubbs de segunda geração, resultaram em materiais insolúveis em uma diversidade de solventes polares e apolares. Testes de inchamento em clorofórmio extraíram frações solúveis dos materiais, compostas por poliNBE e unidades NOP não polimerizadas. Dados obtidos por TGA sugerem a presença de cis e trans poliNBE, além de uma etapa de degradação desconhecida, atribuída ao copolímero poli(NOP-co-NBE) o qual seria o componente insolúvel resultante dos experimentos de inchamento. Assim, os materiais desenvolvidos foram classificados como blendas poliméricas de poliNBE e poli(NOP-co-NBE). Foram avaliados os tempos de gelificação de amostras com diferentes concentrações de catalisador e combinações NOP/NBE através de RMN em baixo campo magnético, obtendo-se comportamentos regulares que podem permitir a previsão do tempo de gelificação de outras amostras. A análise da distribuição dos valores de T2 mostrou aumento na rigidez dos materiais finais ao se aumentar o teor inicial de NOP. / New polymeric materials have been developed using palm oil as a raw material. For this, a new monomer of norbornene, called norbornene palm oil (NPO) was obtained from insertion of norbornene containing the carboxylic group in the palm oil triglycerides. Palm oil as well as products of each step NPO synthesis were characterized by 1H-NMR. It was determined 52% unsaturated fatty acids content in the OP, resulting in NPO with 1.0 norbornene per triglyceride. ROMP reactions of norbornene with NPO, in the presence of the Grubbs second generation catalyst, resulting insoluble materials in a variety of polar and nonpolar solvents. Soluble fractions were extracted in swelling, containing polyNBE and unpolymerized NPO units. TGA data suggests the presence of cis and trans polyNBE, plus an unknown degradation step, attributed to poly(NPO-co-NBE) copolymer which would be insoluble component resulted from the swelling experiments. Thus, the developed materials were classified as polymer blends of polyNBE and poly(NPO-co-NBE). The gelation times of samples having different catalyst concentrations and NPO/NBE combinations were evaluated by low magnetic field NMR, obtaining regular behaviors that may allow the gelation time prediction of other samples. The analysis of T2 values distribution showed increased in the stiffness of the final material by increasing the initial NPO content.