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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Self-Assembly of Organic Nanostructures

Wan, Albert 2011 August 1900 (has links)
This dissertation focuses on investigating the morphologies, optical and photoluminescence properties of porphyrin nanostructures prepared by the self-assembly method. The study is divided into three main parts. In the first part, a large variety of porphyrin nanostructures, including nanoplates, nanofibers, nanoparticles and nanowires, were obtained through direct acidification of tetra(p-carboxyphenyl)porphyrin (TCPP) in aqueous solution. Protonation of the carboxylate groups of TCPP resulted in the formation of nanoplates through the J-aggregation of the porphyrin. Further protonating the core nitrogens of TCPP formed the porphyrin diacids which organized into well-defined structures through their interactions with counter-anions in the solution. The structures of the resulting assemblies were found to be counterion dependent. In the second part of this work, we explored the optical memory effect of the porphyrin thin film. We found that the morphology and the emission of the porpyrin thin film on Si can be changed by varying the pH of its surrounding solution. The changing in morphology and light emission of the thin film resulted from the protonation or deprotonation of TCPP'S core nitrogens. By selectively deprotonating the TCPP dications in a confined region utilizing the water meniscus between an AFM tip and the surface, Fluorescence patterns can be generated on the thin film. The fluorescence patterns can be easily erased by re-protonating the porphyrin. In the third part of this study, porphynoid nanoparticles were deposited on a surface energy gradient, and then characterized by AFM in order to investigate how the surface energy influences thier morphologies. The surface energy gradient was prepared by selectively oxidizing a self-assembly monolayer of octadecyltrichlorosilane (OTS) by UV-ozone. The nanoparticles disassemble into smaller nanoparticles with narrower size distribution on the surface with higher surface energy. Lastly, we engaged in characterizing the morphologies of polymer nanocomposites prepared by layer-by-layer assembly for wettability control. The surface roughness of the nanocopmosite in air and in salt solutions was also measured to study the correlation between the wettability of the polymer surface and its surface roughness.
12

Spectrophotometric analysis of iron porphyrin complexes

Taies, J. A. January 1987 (has links)
No description available.
13

The electron transfer chemistry of nitrosyl complexes

Singh, Priti, January 2008 (has links)
Stuttgart, Univ., Diss., 2008.
14

Characterisation and use of radiotracers in studies of inflammatory tissue and opioid binding sites

Lawrence, Andrew John January 1990 (has links)
The thesis is presented in two parts, part one concerns the synthesis and biodistribution of technetium–porphyrin complexes. A series of compounds with the general formula TcO(Porhyrin)OAc and TcO(Phthalocyanine)OPh have been synthesised via a novel route. The starting material comprised NH4TcO4 with acetic acid for the porphyrin and phenol for the phthalocyanine. The compounds have been characterised both qualitatively and quantitatively by infra-red, ultra-violet and mass spectrometry. Thin Layer Chromatography (TLC) and electrophoresis have also been employed to further analyse the complexes. Preliminary biodistribution studies have been performed in a model of inflamed tissue. The results suggest that the labelled porphyrins are capable of imaging such tissue. One of the complexes was tested for an ability to accumulate in, and image tumours, however this proved unsuccessful.
15

Polypyrrolic macrocycles

Sawka, Richard A. January 1976 (has links)
Synthetic studies toward the preparation of several polypyrrolic macrocycles are described. The majority of the research was directed toward the synthesis of a pentapyrrolic analogue (15) of porphyrin (13). The results were surprising, as a meso-substituted porphyrin (63) was the result. In light of our findings we were able to explain our earlier failures to obtain the pentapyrrole (15) as well as the failures of previous investigators^""*". A sapphyrin (16), the pentapyrrolic analogue of corrole (2), was also prepared, for eventual comparison with our porphyrin analogue (15), and we attempted to insert into 2+ 29 xt a uranyl catxon (UC^ ). The uranyl moiety had been shown to be present in a pentapyrrolic analogue (17) of phthalocyanine (68). By a reaction analogous to that for (17), the synthesis of the five-membered analogue (18) of benzporphyrin (see Scheme 13) was attempted. That macrocycle (18), containing the uranyl ion and being .more porphyrin-like than (17) , would have provided a link between the *superphthalocyanine' (17) and the other macrocycles, (15) and (16). / Science, Faculty of / Chemistry, Department of / Graduate
16

Studies on the Porphyrin and Phthalocyanine Modified on Sno2 Photoelectrochemical Cells

Lin, Chunyu 12 1900 (has links)
The world is facing a tough challenge regarding fulfilling human energy needs. Scientists are motivated to find alternative ways to the fossil fuel at a lower cost with little or no environmental pollution. Among the available renewable resources, the solar energy is an alternative energy to fossil fuel. Scientists are engaged in mimicking the photosynthesis to create the new energy devices such as dye sensitized solar cells. The fundamental theory and properties of the dye sensitized solar cells is given in the first chapter. In this research, the application of the different methods for surface alteration of SnO2 with water soluble porphyrins and phthalocyanine is studied. Using optical absorbance and steady state fluorescence studies, the formation of porphyrins and phthalocyanine discuss on the SnO2 surface is shown. Moreover, the different results of photoelectrochemical cells are show on chapter 2 to understand the porphyrin and phthalocyanine modified on SnO2 as electron injector. In summary, the application porphyrin and phthalocyanine of dimers as a broad band capturing photosensitized dye is discussed.
17

"The porphyrias in South Africa" A study of the excreted porphyrins

Sweeney, George Douglas 16 April 2020 (has links)
Study of the diseases of porphyrin metabolism has formed a major part of the work of the C.S.I.R.- U.C.T. Renal metabolic Research Group since 1959. The scope of the activities of this Group has been wide; this thesis concerns but one aspect, the excreted porphyrins. This is essentially a laboratory study but it is a study that would have lost much of its significance had it not been closely linked to the clinical studies of other members of the group, in particular Prof. L. Eales. The unit has formed a stimulating environment in which to pursue these investigations and it is a. pleasure to acknowledge the contributions to this thesis of all members of the group.
18

Synthesis and Characterization of β-Functionalized π-Extended Porphyrins

Hu, Yi 12 1900 (has links)
Porphyrins with extended π-electronic networks are promising candidates for a wide range of applications from medicine to nanotechnology owing to their unique optical and electronic properties. This dissertation is focused on synthesis, characterization and application of β-functionalized π-extended porphyrins. This dissertation is comprised of seven chapters. Chapter 1 focuses on the importance and objective of this work. Chapter 2 gives brief introduction to porphyrins and π-extended porphyrins. In chapter 3, a class of β-functionalized linear push-pull zinc dibenzoporphyrins YH1-YH3 were designed, synthesized, and utilized as light harvesters for DSSCs. In chapter 4, in order to further enhance the photovoltaic performance of β-functionalized benzoporphyrin dyes based DSSCs, a new class of push-pull dibenzoporphyrins YH4-YH7 bearing the phenylethynyl bridge was designed, synthesized and utilized as light harvesters for DSSCs. In chapter 5, in order to solve the photodegradation problem associated with YH7, a new series of push-pull dibenzoporphyrins YH8-YH10 bearing different diarylamino push groups was designed and synthesized. This class of push-pull porphyrins shows improved photostability and enhanced DSSC performance. In chapter 6, a new pentacene-fused diporphyrin with high stability and solubility was prepared and characterized. Chapter 7 includes the summary of this dissertation and describes possible future work.
19

The synthesis of haematoporphyrin derivative III and other novel porphyrins / Sek Sau Yin

Sek, Sau Yin January 1990 (has links)
Includes bibliographical references / iv, 262, [33] leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1991
20

Study on Metalated and Cross-Conjugated Expanded Porphyrins / 環拡張ポルフィリンの金属錯体及び交差共役系環拡張ポルフィリンに関する研究

Naoda, Koji 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20200号 / 理博第4285号 / 新制||理||1615(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 大須賀 篤弘, 教授 依光 英樹, 教授 丸岡 啓二 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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