Les molécules-aimants ou Single–Molécule Magnets (SMM) ont attiré une attention croissante au cours des dernières années en raison de leur potentiel attrayant en tant que dispositifs de stockage magnétique à haute densité. Beaucoup d'efforts ont été faits pour améliorer la performance magnétique de ces molécules à l’aide des techniques de chimie de coordination.Dans cette thèse, le travail est organisé en deux parties principales. La première partie est constituée des chapitres 2 et 3 qui se concentrent principalement sur les familles Lanthanide-radicaux zéro- et mono-dimensionnelles. La deuxième partie contient les chapitres 4 et 5, ou des ligands diamagnétiques sont utilisés afin concevoir des matériaux multifonctionnels.Dans la première partie, neuf radicaux TEMPO-R (R représente le substituant) sont utilisés. Leur structure cristalline, ainsi que leurs propriétés magnétiques ont été caractérisées. Dans le chapitre 2, quatre radicaux (TEMPO-OCH3, TEMPO-NH2 TEMPO-Acetamido et TEMPO-OCH2CCH) sont utilisés pour synthétiser des complexes zéro-dimensionnels, dont trois présentent des propriétés de SMM. Dans le cas particulier de TEMPO-OCH3, un très rare comportement de SMM avec lanthanides légers est observé (CeIII, PrIII et NdIII). La première SMM à base de PrIII est ainsi reportée. Dans le chapitre 3, l'objectif est de concevoir des SMM organisés mono-dimensionnellement dans l’empilement cristallin. Cinq autres radicaux sont utilisés: TEMPO-Méthacrylate, TEMPO-OCOPh, TEMPO-oxo, TEMPO-OH et TEMPO-CN. Parmi toutes les chaînes obtenues, [Pr(hfac)3(H2O)(TEMPO-OH)]n (17), [Dy(hfac)3-TEMPO-OH)]n (18) et [Tb(hfac)TEMPO-CN)]n (22) sont identifiés comme SMM. 22 présente la relaxation magnétique la plus lente parmi tous les SMM 4f-2p obtenues dans cette thèse, avec une d'hystérèse magnétique à basse température. Son analogue à base GdIII (23) présente une des plus grandes valeurs d'échange dans les composés de Gd-2p. Enfin un très rare exemple de réseau bidimensionnel 4f-2p de formule [(Ce(hfac)3)3(Oxo-TEMPO)4]n (15) est obtenu. Dans la deuxième partie, une chaine de dimère est obtenue par réaction d'un ligand carboxylique photo-commutable avec des sels d’ions LnIII. La photo-sensibilité du ligand sous irradiation UV a été testée et des mesures magnétiques en solution ont été entreprises. En outre, un composé de type Metal-Organic-Framework (MOF) présentant un comportement de SMM de {[Dy2(o-PDA)3(H2O)2]2H2O}n (28) a été conçu et caractérisé. Une interaction ferromagnétique Ln-Ln a été observée dans ce MOF-SMM et le dopage diamagnétique démontre que, contrairement à ce qui est observé sur [Ln(AZO)3(DMSO)(H2O)]2•4DMSO, cette interaction favorise le comportement de SMM. / Single-molecule-magnet (SMM) has attracted increasing attention in recent years due to their appealing potential for high-density storage devices. Much effort has been made to improve the magnetic performance through flexible coordination chemistry strategy.In this thesis, the work is organized in two main parts. The first part is constituted of chapter 2 and chapter 3, primarily focus on the Ln-Radical families aiming at designing zero-dimensional and one-dimensional single-molecule-magnet (SMM). The second part contains chapter 4 and chapter 5, in which the ligands are replaced by diamagnetic ones for the purpose of designing the multifunctional materials.In the first part, nine TEMPO-R (R represents the substituent) radicals are employed to construct zero-dimensional and one-dimensional complexes. These kinds of compounds were prepared by reactions in the dichloromethane/n-heptane co-solvents between the precursor [Ln(hfac)3(H2O)2] and TEMPO radicals. Subsequently their molecular structure as well as magnetic properties have been characterized and described. In chapter 2, four radicals (TEMPO-OCH3, TEMPO-NH2 TEMPO-Acetamido and TEMPO-OCH2CCH) are used to synthesize monometallic or dimetallic complexes, among which three are successful to construct the SMM. For the special case of TEMPO-OCH3 a rare light lanthanide ions (CeIII, PrIII and NdIII) SMM behavior is reported. The PrIII derivative is the first PrIII-based SMM ever reported. In chapter 3, the target is to design SMM in one dimension by using another five radicals: TEMPO-Methacrylate, TEMPO-OCOPh, TEMPO-oxo, TEMPO-OH and TEMPO-CN. Among all the chains, [Pr(hfac)3(H2O)(TEMPO-OH)]n (17), [Dy(hfac)3-TEMPO-OH)]n (18) and [Tb(hfac)3(TEMPO-CN)]n (22) are identified as chains of SMM. 22 exhibits the slowest magnetic relaxation among all the 4f-2p SMMs obtained in this thesis, with a small opening of magnetic hysteresis. Its analogue of [Gd(hfac)3(TEMPO-CN)]n (23) even exhibits one of the largest exchange values in Gd-2p compounds. Last a very rare example of bidimensional 4f-2p network of formula [(Ce(hfac)3)3(Oxo-TEMPO)4]n (15) is obtained.In chapter 4, the salt of a photo-switchable carboxylic ligand was reacted with LnIII ions to afford a chain-like arrangement of dinuclear complexes of formula [Ln(AZO)3(DMSO)(H2O)]2•4DMSO. Photo-sensitivity of the ligand under the irradiation of UV has been tested together with magnetic measurements in solution. In chapter 5, a Metal-Organic-Framework (MOF) (28) has been designed and characterized. Ln-Ln ferromagnetic interaction has been observed and diamagnetic doping highlight that, contrary to what observed on [Ln(AZO)3(DMSO)(H2O)]2•4DMSO, this interaction promote SMM behavior in a so-called MOF-SMM.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24872号 / 理博第4982号 / 新制||理||1711(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 北川 宏, 教授 有賀 哲也, 教授 堀毛 悟史 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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The packaging does not serve as a mere containment but also can be designed to play a key role in preserving the product from quality-deteriorating factors, including oxygen, light irradiation, and foodborne pathogenic microorganisms (e.g., Escherichia coli). There has been a growing interest in employing ultra-porous metal-organic frameworks (MOF) with visible light-responsive antibacterial mechanisms to generate reactive oxygen species (ROS) that can eliminate bacteria via an oxidative burst. MOF is made of inorganic metal ions/nodes/clusters/secondary building units linked by organic bridge ligands, where titanium dioxide (TiO2) and tetrakis(4-carboxyphenyl)porphyrin) (TCPP) were selected for these components, respectively. TiO2 is an exceptional UV-A/B/C-blocker; meanwhile, TCPP dye performs a remarkable photocatalytic ability even under visible light, on top of its macro-heterocyclic structure that is ideal as a MOF linker. Both have good compatibility but suffer from the notorious tendency to self-quench/aggregate. The incorporation of MOF-based conjugates into a polymeric matrix, like cellulose, is among the proven-successful solutions. Cellulose is the Earth's most abundant and naturally biodegradable, and cellulose nanofibril (CNF) was particularly chosen for its high specific surface area and surface activity. However, a straightforward, cheap, and environmentally friendly approach of multicycle homogenization (0-25 passes) was conducted to solve neat cellulose's challenge of natural hydrophilicity, where low pressure (<10 MPa) was applied to prevent the common over-shearing effect. The antibacterial efficacy of CNF films functionalized with TiO2-TCPP conjugate on inhibiting E. coli growth was analyzed with and without light of different intensities (3000 and 6000 lux). The positive impacts of CNFs' promoted fibrillation and subsequent inter/intra-molecular hydrogen bonding post-homogenization were evidenced in an array of functional properties, i.e., crystallinity, TiO2-TCPP conjugate dispersion, surface smoothness, mechanical properties, thermal stability, hydrophobicity, oxygen barrier (comparable to ethylene-vinyl alcohol (EVOH), a commercial high-barrier polymer), and 100%-antibacterial rate (under 6000 lux after 72 hours). Varying optimum cycles of homogenization demonstrated the prospect of the proposed homogenization approach in preparing CNF with diverse processability and applicability. These findings also exhibited a promising potential for a myriad of high-barrier, UV-blocking, and/or visible light-responsive antibacterial film applications, including food packaging and biomedical. / Doctor of Philosophy / Packaging is useful not only as a container but can also be designed to help prevent products from being spoiled due to various reasons such as oxidation, light, and bacterial contamination. Researchers have discovered the promising antibacterial feature of the metal-organic framework (MOF). Packaging made with MOF technology can harness light and oxygen in the environment to produce a special form of oxygen called reactive oxygen species (ROS) that can kill unwanted bacteria. MOF is an extremely porous sponge-like material made of two ingredients: an inorganic metal cluster and an organic linker; in this study, titanium dioxide (TiO2) and a porphyrin called TCPP were selected, respectively. TiO2 is an excellent ultraviolet blocker, while TCPP has a unique, ring-like geometry that is ideal for use as a linker and an antimicrobial feature that works well under the visible light spectrum. The pair are compatible but still suffer from MOF's notorious challenge, where it tends to clump together because of its tiny size. To resolve this problem, TiO2-TCPP MOF can be deposited evenly in a cast made of polymer. Cellulose has been proven to work effectively as a polymeric cast; moreover, it is natural, biodegradable, and in abundant supply. A type of nanosized cellulose—cellulose nanofibril (CNF)—was specifically chosen because its high surface area and activity are useful when blended with other materials. However, cellulose is naturally a poor water-repellant that is not ideal for packaging applications. As a solution, cellulose can be treated with a homogenization technique by passing the material through a very narrow hole under high pressure. Homogenization can be problematic as it possibly damages the cellulose's structure, and its high pressure can also be expensive and energy consuming. Therefore, low pressure with multiple cycles was applied in this work. CNF-TiO2-TCPP films were tested for their ability to slow down E. coli bacteria growth with and without light of varying brightness to compare its light-sensitive antimicrobial feature. Homogenization was found helpful in producing higher-quality CNF, which improved several of the film's final characteristics, including an even material dispersion, structural order, smoothness, strength, heat resistance, and water repellency. Most importantly, it produced films with oxygen barrier ability comparable to commercial high-barrier plastics and completely eliminated bacteria after 72 hours. The optimum number of homogenization cycles was found to be dependent on the desired characteristics and application. Overall, these findings carry a promising potential for a variety of applications, including food packaging and the biomedical field.

The aim of this thesis was to examine the ability of metal organic frameworks (MOFs) to store and controllably release biologically significant amounts of nitric oxide (NO). Initial work involved the synthesis of a series of isostructural MOFs, known as M-CPO-27, which display coordinatively unsaturated metal sites (CUSs) when fully activated (guest solvent molecules both coordinated and uncoordinated to the metal atom are removed). Two of these frameworks (Ni and Co CPO-27) displayed exceptional performance over the entire cycle of activation, storage and delivery showing the largest storage and release of NO of any known porous material (up to 7 mmolg⁻¹). These frameworks would therefore be considered for initial research into the formulation of MOFs, for possible use in medical applications. It was shown that they still release large amounts of NO even when placed inside porous paper bags, creams or hydrocolloids. The other versions of M-CPO-27 also displayed significant adsorption of NO however they show poor total NO release. It was also shown that it is possible to synthesise both Ni and Co CPO-27 using microwave synthesis without any detrimental effect to the porous structure. Several iron-based MOFs were also investigated for NO storage and release. The results showed that Fe MIL-88 based structures adsorb good amounts of NO but only release a small amount of the irreversibly adsorbed NO. Two successfully amine grafted giant pore MOFs were then investigated to attempt to improve the NO adsorption and release. This result was not observed however, due to the poor total amine grafting coverage and pore blockage resulting from the amines. In-situ IR studies reveal that when exposed to NO, activated Fe MIL-100 forms a chemical bond with the NO. The studies also displayed that when water is then allowed to attempt to replace the NO that only a small amount of NO is actually released, the majority of the NO either remains chemically bonded to the Fe atom or forms N₂O in conjunction with a Fe-OH group. Other MOFs were also successfully synthesised and characterised for NO storage and release. Both Ni succinate and Ni STA-12 display good adsorption and excellent release of NO. This indicates that Ni based MOFs show the best results for NO adsorption and release. In the conclusion of the thesis I am able to categorise the NO release ability of MOFs based on composition and formulate a theory as to why this happens.

A modular approach for the synthesis of highly ordered porous and chiral auxiliary (Evans auxiliary) decorated metal–organic frameworks is developed. Our synthesis strategy, which uses known porous structures as model materials for incorporation of chirality via linker modification, can provide access to a wide range of porous materials suitable for enantioselective separation and catalysis. Chiral analogues of UMCM-1 have been synthesized and investigated for the enantioseparation of chiral compounds in the liquid phase and first promising results are reported. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

The research presented in this thesis aims to determine the effectiveness of the uptake of toxic gases by several MOFs for future use in gas-mask cartridges, and to attempt to compensate for any deficiencies they show in “real-world” conditions. The main findings of this thesis confirm that MOFs are suitable candidates for the use in respirator cartridge materials and provide high capacity for adsorption of toxic gases like ammonia and STAM-1 in particular showed an impressive improvement in humid conditions, which normally decrease the performance of MOFs made from the same materials, such as HKUST-1. STAM-1's improved performance in humid conditions is attributed to the structural shift it displays upon dehydration and rehydration and this was shown to be the case in a structural analogue, CuEtOip, which was synthesised in the author's research group. This analogue was analysed using a combination of single crystal XRD and solid state MAS-NMR, both of which showed the structural change occurring and displays similar gas sorption behaviours, suggesting that this mechanism is the source of STAM-1's improved performance in humid conditions. This thesis also examines the “Armoured MOF” process and investigates the transferability of the process of deposition of mesoporous silica onto MOFs with vastly different properties and synthetic methods compared to those published in the original publication. Alongside this, attempts to protect MOFs using mesoporous silicates were investigated for their viability.

The main theme of this dissertation is to engineer nanoporous materials and nanostructured surfaces for applications in gas separation membranes. Tunable methods have been developed to create inorganic hydroxide nanostructures on zeolite surfaces, and used to control the inorganic/polymer interfacial morphology in zeolite/polymer composite membranes. The study of the structure-property relationships in this material system showed that appropriate tuning of the surface modification methods leads to quite promising structural and permeation properties of the membranes made with the modified zeolites. First, a facile solvothermal deposition process was developed to prepare roughened inorganic nanostructures on zeolite pure silica MFI crystal surfaces. The functionalized zeolite crystals resulted in high-quality ̒mixed matrix̕ membranes, wherein the zeolite crystals were well-adhered to the polymeric matrix. Substantially enhanced gas separation characteristics were observed in mixed matrix membranes containing solvothermally modified MFI crystals. Gas permeation measurements on membranes containing nonporous uncalcined MFI revealed that the performance enhancements were due to significantly enhanced MFI-polymer adhesion and distribution of the MFI crystals. Solvothermal deposition of inorganic nanostructures was successfully applied to aluminosilicate LTA surfaces. Solvothermal treatment of LTA was tuned to deposit smaller/finer Mg(OH)₂ nanostructures, resulting in a more highly roughened zeolite surface. Characterization of particles and mixed matrix membranes revealed that the solvothermally surface-treated LTA particles were promising for application in mixed matrix membranes. Zeolite LTA materials with highly roughened surfaces were also successfully prepared by a new method: the ion-exchange-induced growth of Mg(OH)₂ nanostructures using the zeolite as the source of the Mg²⁺ ions. The size/shape of the inorganic nanostructures was tuned by adjusting several parameters such as the pH of the reagent solution and the amount of magnesium in the substrates and systematic modification of reaction conditions allowed generation of a good candidate for application in mixed matrix membranes. Zeolite/polymer adhesion properties in mixed matrix membranes were improved after the surface treatment compared to the untreated bare LTA. Surface modified zeolite 5A/6FDA-DAM mixed matrix membranes showed significant enhancement in CO₂ permeability with slight increases in CO₂/CH₄ selectivity as compared to the pure polymer membrane. The CO₂/CH₄ selectivity of the membrane containing surface treated zeolite 5A was much higher than that of membrane with untreated zeolite 5A. In addition, the use of metal organic framework (MOF) materials has been explored in mixed matrix membrane applications. ZIF-90 crystals with submicron and 2-μm sizes were successfully synthesized by a nonsolvent induced crystallization technique. Structural investigation revealed that the ZIF-90 particles synthesized by this method had high crystallinity, microporosity and thermal stability. The ZIF-90 particles showed good adhesion with polymers in mixed matrix membranes without any compatibilization. A significant increase in CO₂ permeability was observed without sacrificing CO₂/CH₄ selectivity when Ultem® and Matrimd® were used as the polymer matrix. In contrast, mixed matrix membranes with the highly permeable polymer 6FDA-DAM showed substantial enhancement in both permeability and selectivity, as the transport properties of the two phases were more closely matched.

A new mesoporous MOF, Zn4O(bpdc)(btctb)4/3 (DUT-32), containing linear ditopic (bpdc2−; 4,4′-biphenylenedicarboxylic acid) and tritopic (btctb3−; 4,4′,4′′-[benzene-1,3,5-triyltris(carbonylimino)]tris-benzoate) linkers, was synthesised. The highly porous solid has a total pore volume of 3.16 cm3 g−1 and a specific BET surface area of 6411 m2 g−1, adding this compound to the top ten porous materials with the highest BET surface area.