Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14868号 / 工博第3136号 / 新制||工||1470(附属図書館) / 27290 / UT51-2009-K664 / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 榊 茂好, 教授 今堀 博, 教授 杉野目 道紀 / 学位規則第4条第1項該当

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23220号 / 工博第4864号 / 新制||工||1759(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 佐藤 啓文, 教授 佐藤 徹, 教授 田中 勝久 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

The majority of state-of-the-art polymeric membranes for industrial or medical applications are fabricated by phase inversion. Complexation induced phase separation (CIPS)—a surprising variation of this well-known process—allows direct fabrication of hybrid membranes in existing facilities. In the CIPS process, a first step forms the thin metal-rich selective layer of the membrane, and a succeeding step the porous support. Precipitation of the selective layer takes place in the same solvent used to dissolve the polymer and is induced by a small concentration of metal ions. These ions form metal-coordination-based crosslinks leading to the formation of a solid skin floating on top of the liquid polymer film. A subsequent precipitation in a nonsolvent bath leads to the formation of the porous support structure. Forming the dense layer and porous support by different mechanisms while maintaining the simplicity of a phase inversion process, results in unprecedented control over the final structure of the membrane. The thickness and morphology of the dense layer as well as the porosity of the support can be controlled over a wide range by manipulating simple process parameters. CIPS facilitates control over (i) the thickness of the dense layer throughout several orders of magnitude—from less than 15 nm to more than 6 μm, (ii) the type and amount of metal ions loaded in the dense layer, (iii) the morphology of the membrane surface, and (iv) the porosity and structure of the support. The nature of the CIPS process facilitates a precise loading of a high concentration of metal ions that are located in only the top layer of the membrane. Moreover, these metal ions can be converted—during the membrane fabrication process—to nanoparticles or crystals. This simple method opens up fascinating possibilities for the fabrication of metal-rich polymeric membranes with a new set of properties. This dissertation describes the process in depth and explores promising applications: (i) catalytic membranes containing palladium nanoparticles (PdNPs), (ii) antibiofouling tight-UF membranes containing silver chloride (AgCl) crystals, and (iii) palladiumrich PBI hollow fibers for H2 recovery.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20632号 / 工博第4370号 / 新制||工||1679(附属図書館) / 京都大学大学院工学研究科分子工学専攻 / (主査)教授 佐藤 啓文, 教授 白川 昌宏, 教授 山本 量一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24177号 / 理博第4868号 / 新制||理||1697(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 吉村 一良 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24446号 / 理博第4945号 / 新制||理||1706(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 吉村 一良 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Investigations presented here are (a) the study of reorientational dynamics and internal rotation in transition metal complexes by NMR relaxation experiments, and (b) the study of ligand exchange dynamics in transition metal complexes by exchange NMR experiments. The phenyl ring rotation in Ru3(CO)9(μ3-CO)(μ3-NPh) and Re(Co)2(CO)10(μ3- CPh) was monitored by 13C NMR relaxation experiments to probe intramolecular electronic and/or steric interactions. It was found that the rotation is relatively free in the first complex, but is restrained in the second one. The steric interactions in the complexes were ascertained by the measurement of the closest approach intramolecular distances. The rotational energy barriers in the two complexes were also calculated by using both the Extended Hiickel and Fenske-Hall methods. The study suggests that the barrier is due mainly to the steric interactions. The exchange NMR study revealed two carbonyl exchange processes in both Ru3(CO)9(μ3-CO)(μ3-NPh) and Ru3(CO)8(PPh3)(μ3-CO)(μ3-NPh). The lower energy process is a tripodal rotation of the terminal carbonyls. The higher energy process, resulting in the exchange between the equatorial and bridging carbonyls, but not between the axial and bridging carbonyls, involves the concerted formation of edge-bridging μ2-CO moieties. The effect of the PPh3 ligand on the carbonyl exchange rates has been discussed. A combination of relaxation and exchange NMR found that PPh3 ligand rotation about the Ru-P bond is slow on the exchange NMR time scale and the phenyl rotation about the P-Cipso bond is fast on the exchange NMR time scale but is slow on the NMR relaxation time scale.

No description available.

<p>This thesis deals with synthetically modified chiral molecules and their application in asymmetric catalysis. The first part of the thesis describes the use of commercially available chiral diamine ligands in the iridium catalyzed transfer hydrogenation of aromatic ketones. The chiral diamine ligands were mixed with an appropriate transition-metal complex, which after addition of suitable base provided a chiral transition metal complex capable of reducing a range of different aromatic ketones in high yields and enantioselectivities. The developed methodology constitutes a cost effective and readily available procedure for transfer hydrogenation reactions. The following chapters in the thesis are completely devoted to rational design of small organic molecules acting as catalyst in various organocatalytic transformations. Organocatalytic methodology, represent a new and complementary approach to asymmetric organic synthesis, as compared to e.g. transition metal based methodology. Advantages of this methodology typically include mild and less stringent reaction conditions. This, in combination with the lack of toxic transition metal by-products, makes the process more environmentally benign; the organocatalytic methodology, therefore represent a promising approach towards implementation of green chemistry in organic synthesis. Despite this promise, typical drawbacks of the current methodology are long reaction times and the need for high catalyst loadings. Thus, a large demand exists for enhancing reactivity and increasing selectivity in organocatalytic reactions. The present thesis describes several efforts where we have tried to rationally design improved catalysts for various enantioselective organocata-lytic reactions. First, a structurally modified L-proline, incorporating a 1H-tetrazolic acid, was synthesized and evaluated in the direct asymmetric organocatalytic aldol reaction. As shown in Paper II, the catalyst displayed very high reactivity and subsequent studies were initiated in order to rationalize the reactivity enhancement (Paper III). Delightfully, the design principle of a 1H-tetrazolic acid as replacement for a carboxylic acid has since been widely used in the community, including our own efforts in organocatalytic asymmetric cyclopropanations (Paper V)and Diels-Alder reactions (Paper VII). Novel catalysts, including other functionalizations, were also designed for organocatalytic asymmetric addition of nitroalkanes to α,β-unsaturated aldehydes (Paper IV) and for cyclopropanations (Paper VI).</p>

This thesis deals with synthetically modified chiral molecules and their application in asymmetric catalysis. The first part of the thesis describes the use of commercially available chiral diamine ligands in the iridium catalyzed transfer hydrogenation of aromatic ketones. The chiral diamine ligands were mixed with an appropriate transition-metal complex, which after addition of suitable base provided a chiral transition metal complex capable of reducing a range of different aromatic ketones in high yields and enantioselectivities. The developed methodology constitutes a cost effective and readily available procedure for transfer hydrogenation reactions. The following chapters in the thesis are completely devoted to rational design of small organic molecules acting as catalyst in various organocatalytic transformations. Organocatalytic methodology, represent a new and complementary approach to asymmetric organic synthesis, as compared to e.g. transition metal based methodology. Advantages of this methodology typically include mild and less stringent reaction conditions. This, in combination with the lack of toxic transition metal by-products, makes the process more environmentally benign; the organocatalytic methodology, therefore represent a promising approach towards implementation of green chemistry in organic synthesis. Despite this promise, typical drawbacks of the current methodology are long reaction times and the need for high catalyst loadings. Thus, a large demand exists for enhancing reactivity and increasing selectivity in organocatalytic reactions. The present thesis describes several efforts where we have tried to rationally design improved catalysts for various enantioselective organocata-lytic reactions. First, a structurally modified L-proline, incorporating a 1H-tetrazolic acid, was synthesized and evaluated in the direct asymmetric organocatalytic aldol reaction. As shown in Paper II, the catalyst displayed very high reactivity and subsequent studies were initiated in order to rationalize the reactivity enhancement (Paper III). Delightfully, the design principle of a 1H-tetrazolic acid as replacement for a carboxylic acid has since been widely used in the community, including our own efforts in organocatalytic asymmetric cyclopropanations (Paper V)and Diels-Alder reactions (Paper VII). Novel catalysts, including other functionalizations, were also designed for organocatalytic asymmetric addition of nitroalkanes to α,β-unsaturated aldehydes (Paper IV) and for cyclopropanations (Paper VI).