The work is focused on the investigation of synthesis and structure of crystalline coordination networks by combining first a row transition metal ion with one anionic and one neutral bridging ligand. In the field of crystalline coordination networks, the goal is to synthesize porous 3D crystalline coordination networks with molecular sized cavities. The materials are characterized by XRD and TGA. It is important to understand the structural topologies to develop practical applications, such as gas storage, gas separation, and catalysis. The bi- and tetra-dentate flexible imidazole ligands, 9,10-bis(imidazol-1-ylmethyl)anthracene (Chapter 2) and 1, 2, 4, 5-tetrakis(imidazol-1ylmethyl)benzene (Chapter 3), are synthesized and used as linkers to construct 1D, 2D, and 3D crystalline coordination networks with cobalt(II) or zinc(II) cations and H3BTC anions under solvothermal conditions. Two 1D chain networks, [M(HBTC²⁻)(C₂₂H₁₈N₄)(H₂O)₂]•H₂O, are constructed from M(Zn(II) or Co(II)), H₃BTC, and 9,10-bis(imidazol-1-ylmethyl)anthracene (Compound 2.1 and 2.2). These two 1D zigzag chains are linked into infinite 2D sheets by inter-chain π•••π stacking and hydrogen bonding. ⁺ Two 2D and one 3D cobalt(II) coordination networks are constructed from the tetradentate imidazole ligand and H3BTC. Compound 3.1 has a 2D corrugated sheet structure that is linked by inter-layer π•••π stacking and hydrogen bonding. Compound 3.2 has a 2D sheet structure. These sheets are interconnected by hydrogen bonds at the free acid group of the HBTC²⁻ ligand. Compound 3.3 forms a two fold interpenetrated 3D network structure. Void spaces in the structure are filled with six water molecules. Six 3D cobalt (II) coordination networks are constructed with bidentate rigid imidazole containing neutral ligands, 1,4-bis(imidazol-1-yl)benzene(L1), 1,4-bis(imidazol-1-yl)naphthalene(L2), and 9,10-bis(imidazol-1-yl)anthracene(L3), and H₂BDC or H₃BTC anion (Chapter 4). In 4.1-4.3, L1-L3 affects on degree of interpenetrations constructed with H₂BDC ligand. In 4.1 and 4.2 are interpenetrating 3D networks with no accessible void space. In 4.3, void spaces of 3D networks are filled with 2D sheets. Compounds 4.4-4.6 are prepared by different concentrations of starting materials and different solvents. In 4.4-4.6, L3 serves as a pillar building block to construct 3D networks by applying with H₃BTC ligand. The solvent exchange experiment for 4.4 is further discussed. / Ph. D.

Chapter 1: The unique chemical and biological properties of porphyrins have led to increased interest in the development of porphyrin-based materials. Metal organic frameworks (MOFs) can act as a scaffold for the immobilization of porphyrins in desired arrangements. The crystalline nature of MOFs allows for control over spatial arrangement of porphyrins and the local environment of the porphyrin molecules. This opens up the possibility of conducting systematic studies aimed at exploring structure-property relationships. Several strategies for the design and synthesis of porphyrin-based frameworks have been developed over the last two decades, such as, the pillared-layer strategy, construction of nanoscopic metal-organic polyhedrals (MOPs), post-synthetic modification, etc. These strategies provide an opportunity to engineer porphyrin-based MOFs that can target a specific application or serve as multi-functional assemblies. Porphyrin-based MOFs provide a tunable platform to perform a wide variety of functions ranging from gas adsorption, catalysis and light harvesting. The versatile nature of these frameworks can be exploited by incorporating them in multi-functional assemblies that mimic biological and enzymatic systems. Nano-thin film fabrication of porphyrin-based MOFs broadens their application range, making it possible to use them in the construction of photovoltaic and electronic devices. Chapter 2: The reaction of zirconium salts with meso-tetracarboxyphenylporphyrin (TCPP) in the presence of different modulators results in the formation of a diverse set of metal-organic frameworks (MOFs), each displaying distinct crystalline topologies. However, synthesis of phase-pure crystalline frameworks is challenging due to the concurrent formation of polymorphs. The acidity and concentration of modulator greatly influence the outcome of the MOF synthesis. By systematically varying these two parameters, selective framework formation can be achieved. In the present study, we aimed to elucidate the effect of modulator on the synthesis of zirconium-based TCPP MOFs. With the help of powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM), modulator candidates and the optimal synthetic conditions yielding phase-pure PCN-222, PCN-223 and MOF-525 were identified. 1H NMR analysis, TGA and N2 gas adsorption measurements were performed on select MOFs to gain insight into the relationship between their defectivity and modulator properties. Chapter 3: Singlet-singlet energy transfer in PCN-223(free-base), a highly stable Zr-MOF based on meso-tetrakis(4-carboxyphenyl)porphyrin was investigated, using diffuse reflectance spectroscopy, steady-state emission spectroscopy, time-correlated single photon counting (TCSPC) spectroscopy and nanosecond transient absorption spectroscopy. The effects of the surrounding media and temperature on the excited-state properties of PCN-223(fb) were explored to understand the mechanistic aspects of energy transfer. Stern-Volmer photoluminescence quenching of PCN-223(fb) suspensions was performed to extract quenching rate constants and gain insight into the efficiency of energy transfer. Chapter 4: The fourth chapter of this thesis is adapted from chapter 14 of the book "Elaboration and Applications of Metal-Organic Frameworks" authored by Jie Zhu, Shaunak Shaikh, Nicholas J Mayhall and Amanda J Morris. This chapter summarizes the fundamental principles of energy transfer in MOFs and provides an overview of energy transfer in lanthanide-Based luminescent MOFs, Ru/Os-Based MOFs, porphyrin- and metalloporphyrin-based MOF materials, and nonporphyrinic, organic chromophore-based MOFs. / Master of Science / Metal Organic frameworks (MOFs) composed of Zirconium-oxo clusters connected through meso-tetra(4-carboxyphenyl)porphyrin (TCPP) linker molecules have emerged as promising solid-state materials because of their unique structural features and diverse applications. Although these MOFs have demonstrated great potential over the years, synthesizing them in phase-pure form has proven to be very challenging as they are susceptible to polymorphism. Syntheses of these frameworks often result in phase mixtures and have poor reproducibility. To address, this issue, we conducted a systematic exploration of the synthetic parameter landscape to identify reaction conditions for the synthesis of phase-pure Zirconium-based porphyrin MOFs, and to gain deeper insights into the factors governing the formation of these MOFs. We also investigated the defectivity of pristine Zr-TCPP MOFs using a variety of techniques, including 1H NMR spectroscopy, thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry (ICP-MS), and Nitrogen gas adsorption/desorption measurements. The long-term goal of this project is to use phase-pure Zr-based porphyrin MOFs as model systems to study energy transfer in three dimensional structures. To achieve this goal, we characterized the photophysical properties of PCN-223(fb) (a Zr-based porphyrin MOF) using a variety of techniques including steady-state photoluminescence spectroscopy, time-resolved photoluminescence spectroscopy, nanosecond transient absorption spectroscopy and femtosecond transient absorption spectroscopy. Understanding the mechanistic aspects of energy transfer in PCN-223(fb) can pave the way for the design of a new generation of solar energy conversion devices.

Yes / Three highly porous Zr(IV)-based metal–organic frameworks, UBMOF-8, UBMOF-9, and UBMOF-31, were synthesized by using 2,2′-diamino-4,4′-stilbenedicarboxylic acid, 4,4′-stilbenedicarboxylic acid, and combination of both linkers, respectively. The mixed-linker UBMOF-31 showed excellent hydrogen uptake of 4.9 wt% and high selectivity for adsorption of CO2 over N2 with high thermal stability and moderate water stability with permanent porosity and surface area of 2552 m2 g−1. / University of Bath; Royal Society of Chemistry; Engineering and Physical Sciences Research Council

Yes / The synthesis of metal–organic frameworks with large three-dimensional channels that are permanently porous and chemically stable offers new opportunities in areas such as catalysis and separation. Two linkers (L1=4,4′,4′′,4′′′-([1,1′-biphenyl]-3,3′,5,5′-tetrayltetrakis(ethyne-2,1-diyl)) tetrabenzoic acid, L2=4,4′,4′′,4′′′-(pyrene-1,3,6,8-tetrayltetrakis(ethyne-2,1-diyl))tetrabenzoic acid) were used that have equivalent connectivity and dimensions but quite distinct torsional flexibility. With these, a solid solution material, [Zr6O4(OH)4(L1)2.6(L2)0.4]⋅(solvent)x, was formed that has three-dimensional crystalline permanent porosity with a surface area of over 4000 m2 g−1 that persists after immersion in water. These properties are not accessible for the isostructural phases made from the separate single linkers. / Financial support from EPSRC under EP/H000925, access to the HPC service ARCHER via EP/L000202. S.N. thanks the EU for a Marie Curie fellowship (PIEF-GA-2010-274952). C.M.-G. thanks the Spanish MINECO for a Ramón y Cajal Fellowship (RYC-2012-10894).

Yes / Pesticide contamination is a global issue, affecting nearly 44% of the global farming population, and disproportionately affecting farmers and agricultural workers in developing countries. Despite this, global pesticide usage is on the rise, with the growing demand of global food production with increasing population. Different types of porous materials, such as carbon and zeolites, have been explored for the remediation of pesticides from the environment. However, there are some limitations with these materials, especially due to lack of functional groups and relatively modest surface areas. In this regard, metal-organic frameworks (MOFs) provide us with a better alternative to conventionally used porous materials due to their versatile and highly porous structure. Recently, a number of MOFs have been studied for the extraction of pesticides from the environment as well as for targeted and controlled release of agrochemicals. Different types of pesticides and conditions have been investigated, and MOFs have proved their potential in agricultural applications. In this review, the latest studies on delivery and extraction of pesticides using MOFs are systematically reviewed, along with some recent studies on greener ways of pest control through the slow release of chemical compounds from MOF composites. Finally, we present our insights into the key issues concerning the development and translational applications of using MOFs for targeted delivery and pesticide control.

The synthesis, characterization and photophysical properties of three Zr-based Metalorganic frameworks (MOFs) assembled from 2,6-anthracenedicarboxylic acid (2,6-ADCA, 2,6- MOF) and 1,4-anthracenedicarboxylic (1,4-ADCA, 1,4-MOF), and 9,10-anthracenedicarboxylic acid (9,10-ADCA, 9,10-MOF) are described. The crystal structure of the 9,10-MOF was elucidated by synchrotron powder X-ray diffraction (PXRD) analysis and is isostructural with the well-known UiO-66 framework. The 2,6-MOFs also form highly crystalline, octahedral-shaped structures and was characterized by PXRD. Le Bail refinement of the powder pattern revealed that the 2,6-MOF also has UiO-type crystal structure. Conversely, incorporation of the 1,4-ADCA ligand results in large rod-shaped crystals. The excited-state properties of the MOFs were examined using steadstate diffuse reflectance, steady-state emission spectroscopy and time-correlated single photon counting (TCSPC) spectroscopy and are compared to those of the corresponding ligand in solution. Both the unique fluorescent properties of the ligand as well as individual framework structure, result in distinctive luminescent behavior and dictate the extent of intermolecular interactions. Specifically, the 2,6-MOF displays monomeric emission with a fluorescence lifetime (t) of 16.6 ± 1.1 and fluorescence quantum yield (Ff). On the other hand, the 1,4-MOF displays both monomeric and excimeric emission, with corresponding lifetime values of 7.5 ± 0.01 and 19.9 ± 0.1, respectively and a quantum yield of 0.002 ± 0.0001. The propensity for photon upconversion through sensitized triplet-triplet annihilation (TTA-UC) was probed in the three anthracene-based MOFs. The MOFs were surface-modified with Pd(II) mesoporphyrin IX (PdMP) as the triplet sensitizer. Upconverted emission from the 9,10-MOF was observed, with a quantum efficiency (FUC) of 0.46 % and a threshold intensity (Ith) of 142 mW/cm2 . The variation of the spacing between the anthracene units in the MOFs was found to have significant impact on TTA-UC. As a result, upconverted emission is only displayed by the 9-10-MOF. The distance between anthracene linkers in the 2,6-MOF are too large for TTA to occur, while the short distances in the 1,4-MOF inhibit upconversion through competitive excimer formation. To further explore the effects of chromophore spacing on energy transfer processes, a series of zinc-based mixed-ligand MOF were constructed from Zn(II) tetrakis(4- carboxyphenyl)porphyrin (ZnTCPP) and pyrazine, 2,2′-bipyridine (pyz) or 4,4′-bipyridyl (bpy) or 1,4-di(4-pyridyl)benzense (dpbz), comprising ZnTCPP/Zn paddlewheel layers. Across this series, the porphyrin spacing was approximately 6 Å, 11 Å and 16 Å for pyz, bpy and dpbz, respectively. The photophysical properties of the MOFs were explored using stead-state diffuse reflectance spectroscopy and steady-state and time-resolved emission spectroscopies. Florescence quenching studies examined the correlation between porphyrin spacing and efficiency of energy transfer. / Ph. D. / Metal-organic frameworks (MOFs) are crystalline materials composed of metal clusters connected by organic molecules. Their modular nature and synthetic tunability allows for rational design of MOFs with different functionalities and has afforded their application in a variety of fields including gas storage and separation, catalysis, optoelectronics, energy conversion and storage, chemical sensing and biomedicine. MOFs provide an ideal platform for studying the structure-property relationships that govern energy-transfer processes. Furthermore, efficient and long-ranging, directional energy transfer has been demonstrated in MOFs. The work presented in this dissertation focuses on MOFs with applications in solar energy conversion schemes. The design and synthesis of photoactive MOFs is described and the effects of their structure on energy-transfer processes is explored. Photovoltaic cells (PVCs) absorb sunlight and convert it into electricity. However, only photons that are high enough in energy are absorbed by the PVC, while the lower energy photons are not absorbed and therefore do not contribute to power production, resulting in decreased efficiency of the solar cell. One approach to enhancing solar cell efficiencies is to collect the lower energy photons and convert them into higher energy photons through a process called sensitized photon upconversion (UC). This process involves a molecule (sensitizer chromophore) that absorbs lower-energy photons and then transfers the absorbed energy to a second molecule (acceptor chromophore), which emits higher-energy photons. In order to understand how to optimize the efficiency of the UC process, we integrated sensitizer and acceptor chromophores into MOFs various molecular arrangements and probed UC in these materials. Close proximity and he appropriate orientation between chromophores resulted in UC from the framework. Natural photosynthetic systems contain highly ordered arrays of chromophores that efficiently absorb sunlight and funnel the energy to a reaction center. Energy-harvesting materials that mimic natural photosynthetic processes also have potential applications in solar energy conversion. Porphyrins are often used in artificial photosynthetic systems because of their similarity to chlorophyll pigments found in nature. In order to design highly efficient artificial photosynthetic systems, we first need to understand how energy transfer processes are influenced by the structure of the system. Therefore, we synthesized a series of MOFs containing Zn=porphyrin layers at varied distances and examined the effects of distance between porphyrin layers on the energy-transfer processes within the MOFs. This work provides insight into the structure-property relationships in photoactive MOFs that can serve as a guide for the rational design of light-harvesting MOFs in future studies.

Les MOFs résultent de l’organisation de polyèdres métalliques reliés par des molécules organiques chélatantes pour former un réseau poreux. La construction de solides hybrides organiques/inorganiques permet d’imaginer un très grand nombre de matériaux aux propriétés structurales et physico-chimiques variées. Le confinement du substrat dans une structure rigide, associé à des propriétés particulières des clusters métalliques ainsi qu’à des parois pouvant être fonctionnalisées, fournissent un environnement catalytique unique, plaçant les MOF à la frontière entre les espèces types zéolites et les enzymes. Cependant, il existe aujourd’hui très peu de MOFs possédant plus d’une fonction catalytique. Néanmoins, les propriétés catalytiques des MOFs peuvent être améliorées de façons non négligeables grâce aux méthodes de post-fonctionalisation. Dans ce travail, nous reportons le développement d’une méthode de post-fonctionnalisation originale des amino-MOFs. La première étape consiste à convertir la fonction amine en fonction azoture. Puis, sans isolation ni purification, le MOF fonctionnalisé est obtenu par « Click Chemistry » en ajoutant l’alcyne correspondant. Cette méthode peut être appliquée à tous les types d’amino-MOFs et à quasi toutes les fonctions chimiques que l’on souhaite greffer. Une large librairie de nouveaux matériaux a ainsi été obtenue et complètement caractérisée. Cette méthode a aussi été utilisée pour créer des MOFs catalytiques à façon pour une réaction de transesterification, ainsi que pour l’investigation de nouvelles applications plus fines (niches industrielle) / MOFs result from the association of metallic clusters connected by organic linkers to form a net. It is acknowledged that ultimately MOFs could mimic “enzymes” using “molecular recognition” concept to allow high chemio-, regio-, enantio-selectivity. We could indeed anticipate MOFs as potential “artificial enzymes” that can combine several properties at the nanometer scale in a concerted fashion. However to date, the number of MOFs with more than one reactive “catalytic” function is rather scarce. A key to address advanced MOF materials suitable for more sophisticated applications is to add functionalities of greater complexity in a controlled manner. The ability to modify the chemical environment of the cavities within MOFs would allow tuning of the interactions with guest species, and serve as a route to tailor the chemical reactivity of the framework. However, the introduction of reactive chemical functions by self-assembly methods is not a trivial task. In this work, we report an original PSM method starting from amino derived MOFs. The first step consists in converting the amino group into azide (N3). Without isolation nor purification, the desired functionalized material is obtained by grafting the corresponding alkyne using “Clik Chemistry”. This method can be applied to all kind of amino-MOFs and to all kind of grafted chemical functions. A diverse library of original MOFs was synthesized and characterized. Finally, this method was used to engineer catalytic MOFs for the transesterification of ethyldecanoate with methanol or to investigate applications in specialized industrial niches

Polímeros de coordenação têm atraído a atenção de pesquisadores na última década por conta de sua incrível versatilidade e virtualmente infinito número de possibilidades de combinação de ligantes orgânicos e centros metálicos. Estes compostos normalmente herdam as características magnéticas, eletrônicas e espectroscópicas de seus componentes base. Entretanto, apesar do crescente número de trabalhos na área, ainda são raros os polímeros de coordenação que apresentem condutividade elétrica. Para este fim, utilizou-se a N,N\'-bis(4-piridil)-1,4,5,8-naftaleno diimida, ou NDI-py, que pertence a uma classe de compostos rígidos, planares, quimicamente e termicamente estáveis e que já foram extensamente estudados por suas propriedades fotoeletroquímicas e semicondução do tipo n. O primeiro polímero de coordenação sintetizado, MOF-CoNDI-py-1, indicou ser um polímero linear, de estrutura 1D. O segundo, MOF-CoNDI-py-2, que conta com ácido tereftálico como ligante suporte, é um sólido cristalino com cela unitária monoclínica pertencente ao grupo espacial C2/c, determinado por difração de raios-X de monocristal. A rede apresenta um arranjo trinuclear de íons Co(II) alto spin com coordenados em uma geometria de octaedro distorcido, enquanto os ligantes NDI-py se encontram em um arranjo paralelo na estrutura, em distâncias apropriadas para transferência eletrônica. Com o auxílio de cálculo teóricos a nível de DFT, foi realizado um estudo aprofundado dos espectros eletrônicos e vibracionais, com atribuição das transições observadas, tanto para o MOF-CoNDI-py-2 quanto para o ligante NDI-py livre. A rede de coordenação absorve em toda a região do espectro eletrônico analisada, de 200 nm a 2500 nm, além de apresentar luminescência com característica do ligante. Dispositivos eletrônicos fabricados com um cristal do MOF-CoNDI-py-2 revelaram condutividades da ordem de 7,9 10-3 S cm -1, a maior já observada para um MOF. Além de elevada, a condutividade elétrica dos cristais demonstrou-se altamente anisotrópica, sendo significativamente menos condutor em algumas direções. Os perfis de corrente versus voltagem foram analisados em termos de mecanismos de condutividade, sendo melhores descritos por um mecanismo limitado pelo eletrodo to tipo Space-Charge Limited Current, concordando com a proposta de condutividade através dos planos de NDI-py na rede. A condutividade dos cristais também é fortemente dependente de luz, apresentando fotocondução quando irradiado por um laser vermelho, de 632 nm, enquanto apresenta um comportamento fotorresistivo frente a uma fonte de luz branca. Estes resultados, combinados, trazem um MOF em uma estrutura incomum e com elevada condutividade elétrica, modulada por luz, em medidas diretas de corrente. Não existem exemplos conhecidos de MOFs na literatura com estas características. / Coordination polymers have been a major topic in materials science during the past decade, thanks to their versatility and virtually infinite possible combinations between metal centers and organic ligands. These coordination polymers usually inherit the properties of their components, such as magnetic, spectroscopic and electronic characteristics. However, despite the increasing number of research papers in this topic, it is still hard to find coordination polymers featuring electronic conductivity. To achieve that, we used a naphthalene diimide derivative, N,N\'-bis(4-pyridyl)-1,4,5,8- naphthalene diimide or NDI-py, which belongs to a class of rigid, planar, thermally and chemically stable compounds, extensively studied due to their photoelectrochemical properties and their n-type semiconductivity. The first coordination polymer synthesised, MOF-CoNDI-py-1, was an amorphous linear polymer, with a 1D structure. Based on these observations, MOF-CoNDI-py-2 was synthesised by using terephthalic acid as a supporting ligand, and it is a crystalline solid which its monoclinic unit cell belongs to a C2/c space group, as determined by single crystal X-ray diffraction. This network features a trinuclear high-spin Co(II) unit, and each metal ion sits on a distorted octahedra coordination geometry, while the NDI-py ligands sit in a parallel arrangement, with distances suitable for electronic transfers. A detailed study of their vibrational and electronic spectra, supported by DFT calculations, was performed, as well as a full description and assignment of the observed bands. MOF-CoNDI-py-2 absorbs in the whole studied spectral region, from 200 nm to 2500 nm, while it also features a ligand-centered emission spectrum. Electronic devices built around its crystals revealed electric conductivities of 7.9 10 -3 S cm -1, which is, to the best of our knowledge, the highest for a MOF to this date. This conductivity is also highly anisotropic, being significantly less conductive in certain directions. The current versus voltage profiles were analysed in terms of known conduction mechanisms, with best fits when using an electrode-limited Space-Charge Limited Current mechanism, in agreement with the proposition that this conductivity happens through the NDI-py stacking planes. Additionally, this mechanism is influenced by an external light source, being a photoconductor with a red laser, 632 nm, and a photoresistor with a white light. Combined, these results bring a light-modulated, highly conductive MOF material with an unusual structure. As far as we know, there are no similar MOFs in the literature, which makes MOF-CoNDI-py-2 one of a kind.

Les Poly(HydroxyAlcanoates) (PHA) sont des polymères naturels, biodégradables et biocompatibles, synthétisés par de nombreux organismes, et plus particulièrement des procaryotes. Il existe à ce jour plus de 150 types de monomères de PHA différents, accumulés chez différents genres bactériens, en tant que source d’énergie et de carbone. En effet, les granules de PHA intracellulaires sont produites en réponse à un apport en excès de sources de carbone dans l’environnement (glucides, acides gras…), couplé à une carence en éléments azotés nécessaires à la division cellulaire. De par leur caractère biodégradable et biocompatible, les PHA sont employés depuis plus de 20 ans comme biomatériaux dans les domaines pharmaceutiques et biomédicaux, notamment comme micro/nanovecteurs à visée thérapeutique. Ce doctorat met en évidence des méthodes de criblage moléculaire par PCR pour la sélection de bactéries productrices de PHA, isolées de sites hydrothermaux des océans Atlantique et Pacifique au cours de campagnes océanographiques Ifremer. Selon des protocoles de fermentation standardisés et optimisés, des polymères de poly(3-hydroxybutyrate-4-hydroxybutyrate) P(3HB4HB) d’intérêt biomédical ont été produits, puis des études taxonomiques et phylogénétiques ont été menées pour explorer la biodiversité microbienne associée aux environnements marins profonds. Ensuite, des PHA ont été modifiés par réaction thiol-ène photoactivée afin d’obtenir des copolymères hydrosolubles, adaptés pour l’enrobage de nanoparticules poreuses de type Metal-Organic Frameworks (MOF). La caractérisation physicochimique a été réalisée par différentes techniques, et notamment par SEM et STEM-EDX. Les systèmes hybrides poreux MOF-PHA ont ensuite été évalués quant à leur biocompatibilité vis-à-vis de cellules immunitaires (macrophages), par des tests de cytotoxicité et de prolifération cellulaire. Cette étude met en lumière les potentialités de cette nouvelle génération de nanovecteurs, synthétisés pour augmenter le bénéfice thérapeutique tout en minimisant les effets secondaires sur l’organisme humain. / Poly(HydroxyAlkanoates) (PHA) are natural polymers, biodegradable and biocompatible, synthesized by many organisms, especially prokaryotes. There are over 150 kinds of these polyesters, accumulated in a wide variety of bacteria as carbon and energy storage material. PHA granules are deposited intracellularly when microorganisms are cultivated in the presence of an excess of carbon source (glucids, fatty acids...) together with a nitrogenous nutrient deficiency. Due to their biodegradability and biocompatibility, PHA can be used as biomaterials in medical or pharmaceutical fields, and numerous therapeutic micro/nanovectors have already been developed over the past two decades.The present PhD research project highlighted molecular screening methods by PCR for the PHA producing Bacteria selection, isolated during Ifremer cruises from hydrothermal vents in Atlantic and Pacific oceans.According to standardized and optimized fermentation protocols, poly(3-hydroxybutyrate-4-hydroxybutyrate) P(3HB4HB) polymers of biomedical interest were produced, then taxonomic and phylogenetic studies were performed to explore microbial biodiversity associated with deep-sea environments. Next, PHA were modified by ‘click chemistry’ to obtain hydrosoluble copolymers, suitable for coating high porous Metal-Organic Frameworks (MOF) therapeutic nanoparticles. Physico-chemical characterization was performed using different techniques, and more particularly by SEM and STEM-EDX. MOF-PHA hybrid porous systems were then evaluated for their biocompatibility against immune cells (macrophages), by cytotoxicity and cellular proliferation tests. This study highlights potentials of these new generations of nanovectors, synthesized to increase the therapeutic benefit while minimizing side effects on the human body.

Polímeros de coordenação têm atraído a atenção de pesquisadores na última década por conta de sua incrível versatilidade e virtualmente infinito número de possibilidades de combinação de ligantes orgânicos e centros metálicos. Estes compostos normalmente herdam as características magnéticas, eletrônicas e espectroscópicas de seus componentes base. Entretanto, apesar do crescente número de trabalhos na área, ainda são raros os polímeros de coordenação que apresentem condutividade elétrica. Para este fim, utilizou-se a N,N\'-bis(4-piridil)-1,4,5,8-naftaleno diimida, ou NDI-py, que pertence a uma classe de compostos rígidos, planares, quimicamente e termicamente estáveis e que já foram extensamente estudados por suas propriedades fotoeletroquímicas e semicondução do tipo n. O primeiro polímero de coordenação sintetizado, MOF-CoNDI-py-1, indicou ser um polímero linear, de estrutura 1D. O segundo, MOF-CoNDI-py-2, que conta com ácido tereftálico como ligante suporte, é um sólido cristalino com cela unitária monoclínica pertencente ao grupo espacial C2/c, determinado por difração de raios-X de monocristal. A rede apresenta um arranjo trinuclear de íons Co(II) alto spin com coordenados em uma geometria de octaedro distorcido, enquanto os ligantes NDI-py se encontram em um arranjo paralelo na estrutura, em distâncias apropriadas para transferência eletrônica. Com o auxílio de cálculo teóricos a nível de DFT, foi realizado um estudo aprofundado dos espectros eletrônicos e vibracionais, com atribuição das transições observadas, tanto para o MOF-CoNDI-py-2 quanto para o ligante NDI-py livre. A rede de coordenação absorve em toda a região do espectro eletrônico analisada, de 200 nm a 2500 nm, além de apresentar luminescência com característica do ligante. Dispositivos eletrônicos fabricados com um cristal do MOF-CoNDI-py-2 revelaram condutividades da ordem de 7,9 10-3 S cm -1, a maior já observada para um MOF. Além de elevada, a condutividade elétrica dos cristais demonstrou-se altamente anisotrópica, sendo significativamente menos condutor em algumas direções. Os perfis de corrente versus voltagem foram analisados em termos de mecanismos de condutividade, sendo melhores descritos por um mecanismo limitado pelo eletrodo to tipo Space-Charge Limited Current, concordando com a proposta de condutividade através dos planos de NDI-py na rede. A condutividade dos cristais também é fortemente dependente de luz, apresentando fotocondução quando irradiado por um laser vermelho, de 632 nm, enquanto apresenta um comportamento fotorresistivo frente a uma fonte de luz branca. Estes resultados, combinados, trazem um MOF em uma estrutura incomum e com elevada condutividade elétrica, modulada por luz, em medidas diretas de corrente. Não existem exemplos conhecidos de MOFs na literatura com estas características. / Coordination polymers have been a major topic in materials science during the past decade, thanks to their versatility and virtually infinite possible combinations between metal centers and organic ligands. These coordination polymers usually inherit the properties of their components, such as magnetic, spectroscopic and electronic characteristics. However, despite the increasing number of research papers in this topic, it is still hard to find coordination polymers featuring electronic conductivity. To achieve that, we used a naphthalene diimide derivative, N,N\'-bis(4-pyridyl)-1,4,5,8- naphthalene diimide or NDI-py, which belongs to a class of rigid, planar, thermally and chemically stable compounds, extensively studied due to their photoelectrochemical properties and their n-type semiconductivity. The first coordination polymer synthesised, MOF-CoNDI-py-1, was an amorphous linear polymer, with a 1D structure. Based on these observations, MOF-CoNDI-py-2 was synthesised by using terephthalic acid as a supporting ligand, and it is a crystalline solid which its monoclinic unit cell belongs to a C2/c space group, as determined by single crystal X-ray diffraction. This network features a trinuclear high-spin Co(II) unit, and each metal ion sits on a distorted octahedra coordination geometry, while the NDI-py ligands sit in a parallel arrangement, with distances suitable for electronic transfers. A detailed study of their vibrational and electronic spectra, supported by DFT calculations, was performed, as well as a full description and assignment of the observed bands. MOF-CoNDI-py-2 absorbs in the whole studied spectral region, from 200 nm to 2500 nm, while it also features a ligand-centered emission spectrum. Electronic devices built around its crystals revealed electric conductivities of 7.9 10 -3 S cm -1, which is, to the best of our knowledge, the highest for a MOF to this date. This conductivity is also highly anisotropic, being significantly less conductive in certain directions. The current versus voltage profiles were analysed in terms of known conduction mechanisms, with best fits when using an electrode-limited Space-Charge Limited Current mechanism, in agreement with the proposition that this conductivity happens through the NDI-py stacking planes. Additionally, this mechanism is influenced by an external light source, being a photoconductor with a red laser, 632 nm, and a photoresistor with a white light. Combined, these results bring a light-modulated, highly conductive MOF material with an unusual structure. As far as we know, there are no similar MOFs in the literature, which makes MOF-CoNDI-py-2 one of a kind.