Dissertations / Theses on the topic 'Para-Phenylene'
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1
Kankate, Laxman. "Light emitting organic nanofibers from para-phenylene and alpha-thiophene oligomers." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2008. http://dx.doi.org/10.18452/15775.
Abstract:
Wir haben blau, grün und orange leuchtende organische Nanofäden oder Nanonadeln und Mikroringe aus para-Hexaphenyl (p-6P), alpha-Quaterthiophen (alpha-4T) und alpha-Sexithiophen (alpha-6T) mittels Organischer Molekularstrahlepitaxie (OMBE) auf Muskovit Glimmer hergestellt. Die Aggregate haben wir mit der Atomkraftmikroskopie, mit der Fluoreszenz-Mikroskopie und durch UV-vis Spektroskopie charakterisiert. Auf der Muskovit Oberfläche wachsen p-6P Fäden parallel zueinander auf und zeigen zwei verschiedene Orientierungsdomänen entlang [110] und [1-10]. Mit Hilfe einer systematischen statistischen Analyse diskutieren wir das Wachstum dieser p-6P Nadeln für verschiedene Wachstumsbedingungen. Zusätzlich zu den Fäden haben wir p-6P Cluster auf der Oberfläche beobachtet. Nadeln werden durch die Aggregation solcher Cluster gebildet. Ein Realraummodell der Morphologie der Nadeln sowie ein Modell für deren Wachstum werden vorgestellt. Indem wir Glimmer zunächst mit einer dünnen Goldschicht bedecken und die Wachstumsparameter variieren, erreichen wir eine weitgehende Kontrolle der Morphologie der Nadeln (Länge von 0,5 Mikrometer bis 1 mm, Höhe von 25 bis 300 nm und Breite von 100 bis 600 nm). Im Gegensatz zu p-6P orientieren Thiophene ihre Wachstumsrichtungen an allen hoch symmetrischen Richtungen von Glimmer. Es wird gezeigt, dass die Mechanismen für das Fadenwachstum von beiden Oligomere gleich sind, nämlich eine Kombination aus Epitaxie und einer Dipol-unterstützten Ausrichtung. Auch die Strukturen dieser Fäden sind ähnlich: die Moleküle liegen parallel angeordnet auf der Oberfläche, ihre Längsachsen orientieren sich schräg zur Längsachse der Fäden. Auf mit Wasser oder Methanol vorbehandeltem Glimmer wachsen diese beiden Oligomere als gebogene Fäden und Mikroringe auf. Diese Oberflächenvorbehandlungen sowie das Wachstum von p-6P auf Gold/Glimmer unterstützen auch den Wachstumsmechanismus auf der sauberen Glimmer-Oberfläche.By using organic molecular beam epitaxy (OMBE) blue, green and orange light emitting organic nanofibers or nanoneedles and microrings from para-hexaphenyl (p-6P), alpha-quaterthiophene (alpha-4T) and alpha-sexithiophene (alpha-6T), respectively, on muscovite mica surfaces are generated. The aggregates are characterized by atomic force microscopy, fluorescence microscopy and UV-vis spectroscopy. On muscovite mica, p-6P fibers usually grow mutually parallel showing two domains of their orientations with an angle of 120 degree in between. The detail growth of nanofibers from p-6P by performing a systematic statistical analysis of fibers as a function of various growth conditions is discussed. Furthermore, the morphology exhibits p-6P clusters, which are found to be fibers´ building blocks. A real space model of the fiber and a model for their growth are also presented. By introducing a thin gold layer on mica prior to p-6P deposition together with varying growth parameters, the morphology of fibers is controlled in a wide range (length from 0.5 micrometer to 1 mm, height from 25 to 300 nm and width from 100 to 600 nm). In contrast to p-6P, thiophene fibers exhibit various orientations close to mica high symmetry directions. It is shown that the mechanism behind the fiber growth from all molecules on mica is the same, i.e. a combination of epitaxy and dipole assisted growth process. The fiber microscopic structures are similar, too: molecules take lying orientations and they hold themselves parallel pointing their long axes along an oblique direction off the long fiber axis. The growth of both types of oligomers on water or methanol treated mica surfaces leads to the formation of bent fibers and microrings. This surface pretreatment and the growth of p-6P on gold/mica support the fiber growth mechanism on plain mica.
2
Cai, Qingrui. "Temperature and pressure raman studies of Hg1201 superconductors and oligo (para-phenylene) materials /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3025607.
3
De, Souza Melanie Maria. "Photophysical studies of chromophores in conjugated polymers and model compounds based on para-phenylene vinylene." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394385.
4
von, Irmer Jonas [Verfasser], Matthias [Akademischer Betreuer] Rehahn, and Christina M. [Akademischer Betreuer] Thiele. "Suzuki-Polykondensation hochmolekularer Poly-para-phenylene mittels Mikrowellenstrahlung / Jonas von Irmer ; Matthias Rehahn, Christina M. Thiele." Darmstadt : Universitäts- und Landesbibliothek, 2021. http://d-nb.info/1228074135/34.
5
Kobin, Björn. "Ladder-type oligo-(p-phenylene)s for hybrid optoelectronic devices based on resonant energy transfer." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17556.
Abstract:
In der heutigen Zeit sind optoelektronische Bauelemente allgegenwärtig. Sie finden Anwendung für Beleuchtungszwecke, in Anzeigen und für die Telekommunikation. Die Entwicklung dieser Anwendungen wurde lange Zeit von anorganischen Halbleitern getragen, in jüngerer Vergangenheit auch von der organischen Elektronik. Neuerdings werden verstärkt Konzepte entwickelt, um die spezifischen Vorteile der jeweiligen komplementären Materialklassen auszunutzen. Für diese Hybridisierung müssen die Eigenschaften der verschiedenen Materialien, insbesondere die elektronische Struktur, genau auf einander abgestimmt sein. In dieser Arbeit werden Leiter-para-phenylene auf spektrale Überlagerung und angepasste Orbitalenergien mit ZnO, auf chemische Inertheit und auf die Bildung von dünnen Schichten über vakuumbasierte Verarbeitungsmethoden optimiert. Dazu konzentriert sich der synthetische Gesichtspunkt auf die selektive Funktionalisierung der verschiedenen Methylenbrücken mit Alkyl-, Aryl- und Fluorsubstituenten. Die finalen Stufen werden bezüglich ihrer optischen Eigenschaften mittels Absorption und Fluoreszenz, bezüglich ihrer elektrochemischen Eigenschaften und bezüglich ihrer Festkörperstruktur mittels Röntgenstrukturanalyse von Einkristallen charakterisiert. Außerdem widmet sich ein erheblicher Teil dieser Arbeit der Erforschung des photochemischen Abbaus von fluorenbasierten Strukturen. Es werden neue Erkenntnisse zum Abbaumechanismus und der Ursache der grünen Emission gewonnen. Weiterhin werden die Abbauraten von Fluorenstrukturen mit verschiedenen Brückensubstituenten verglichen. Dabei konnten auch verschiedene Reaktionsprodukte und Mechanismen nachgewiesen werden. Letztendlich wird auch die Anwendung einzelner Derivate in Hybridstrukturen diskutiert.Nowadays optoelectronic devices are ubiquitous for illumination purposes, in telecommunication and displays. For a long time, the development for these devices was driven by inorganic semiconductors, later organic semiconductors contributed, as well. Recently concepts have been developed to combine both complementary material classes to exploit the specific advantages of each one. For the hybridization, the properties of the materials, especially the electronic structure, have to match very well. In this work the optimization of ladder-type p-phenylenes towards spectral overlap and energy level alignment with ZnO, vacuum-processability, inertness, as well as layer formation is described. In terms of molecular design the different properties are addressed by site-selective functionalization of the methylene bridges with alkyl, aryl, and fluoro groups. The final products are characterized regarding their optical properties by absorption and fluorescence, their electrochemical properties, as well as their solid-state structure by single crystal X-ray diffraction. Apart from that, a large part of the work is devoted to investigations of the photochemical degradation of fluorene-type structures. New insights are gained into the mechanism of degradation, as well as the origin of the green emission in ladder-type structures The dependence of the rate of degradation is described semi-quantitatively with respect to the substitution pattern. By that, different reaction mechanisms for different substituents are found. Finally, the integration of some products in hybrid structures is discussed.
6
Kub, Christopher. "Hyperbranched conjugated polymers: an investigation into the synthesis, properties and postfunctionalization of hyperbranched poly(phenylene vinylene-phenylene ethynylene)s." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34838.
Abstract:
There are two general ways to introduce functionalities into a polymeric structure: functionalization of the monomeric units before polymerization and postfunctionalization of the preformed polymer. Building libraries of polymers with different functionalities can be completed with significantly less effort by the second method, as each postfunctionalization of a single batch of polymeric backbone can involve as little as one synthetic step.
One method of building a polymeric backbone for postfunctionalization involves the synthesis of hyperbranched conjugated polymers (HCPs) from AB2 monomeric units. A polymer formed from n AB2 monomeric units should contain n reactive B groups, which act as sites of functionalization. Utilizing this principle, two different hyperbranched poly(phenylene vinylene-phenylene ethynylene) scaffolds were synthesized and studied in both their inherent properties and functionalization.
The first HCP synthesized was compared against a monomeric cruciform model and a linear polymer with a similar structure. The hyperbranched polymer has red-shifted absorption and emission in comparison to the cruciform model and linear polymer. The HCP quenches paraquat more efficiently than the linear polymer by a factor of about two, suggesting a greater rate of energy transfer.
The functionalization of HCPs was studied; iodine groups decorating the HCPs were replaced with terminal alkynes by Pd-catalyzed coupling, providing a library of 24 differently functionalized HCPs. Elemental analyses of the postfunctionalized polymers show nearly complete substitution of the iodine groups. The postfunctionalized polymers show increased fluorescence compared to the original iodine decorated polymers, due to the loss of the heavy atom effect inducing iodine groups. The emissions of the postfunctionalized polymers in solution show a strong dependence on the groups attached to the conjugated structures, with emission maxima ranging from 505 nm to 602 nm; quantum yields range from 0.7% to 25%. Solid-state emission studies show stronger and more red-shifted spectra compared to emissions observed in solution.
7
Mirsakiyeva, Amina. "Electronic and optical properties of conducting polymers from quantum mechanical computations." Doctoral thesis, KTH, Materialfysik, MF, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214979.
Abstract:
Conductive polymers are also known as "organic metals" due to their semiconducting properties. They are found in a wide range of applications in the field of organic electronics. However, the growing number of experimental works is not widely supported with theoretical calculations. Hence, the field of conductive polymers is experiencing lack of understanding of mechanisms occurring in the polymers. In this PhD thesis, the aim is to increase understanding of conductive polymers by performing theoretical calculations. The polymers poly(3,4-ethylenedioxythiophene) (PEDOT) together with its selenium (PEDOS) and tellurium (PEDOTe) derivatives, poly(p-phenylene) (PPP) and naphthobischalcogenadiazoles (NXz) were studied. Several computational methods were applied for analysis of mentioned structures, including density functional theory (DFT), tight-binding modelling (TB), and Car-Parrinello molecular dynamics (CPMD) calculations. The combination of CPMD and DFT calculations was applied to investigate the PEDOT, PEDOS and PEDOTe. The polymers were studied using four different functionals in order to investigate the full picture of structural changes, electronic and optical properties. Temperature effects were studied using molecular dynamics simulations. Wide statistics for structural and molecular orbitals analysis were collected. The TB method was employed for PPP. The formation and motion of the excitations, polarons and bipolarons, along the polymer backbone was investigated in presence of electric and magnetic fields. The influence of non-magnetic and magnetic impurities was determined. The extended π-conjugated structures of NXz were computed using B3LYP and ωB97XD functionals in combination with the 6-31+G(d) basis set. Here, the structural changes caused by polaron formation were analyzed. The combined analysis of densities of states and absorption spectra was used for understanding of the charge transition.QC 20170928
8
DULIEU, BERTRAND. "Relaxation lente des porteurs de charge dans la perovskite feuilletee nd#2ti#3o#9 et dans le polymere conjugue poly(para-phenylene-vinylene)." Nantes, 1997. http://www.theses.fr/1997NANT2064.
Abstract:
Ce travail presente l'etude des proprietes photoconductrices de la perovskite feuilletee nd#2ti#3o#9 et du polymere conjugue poly(para-phenylene-vinylene) ppv. Le phenomene commun, qui relie ces deux etudes, est le caractere lent de la relaxation des porteurs de charge dans les deux materiaux. Dans nd#2ti#3o#9, les declins de photoconductivite, sous vide et en fonction de la temperature, sont bien decrits a l'aide de l'exponentielle etiree ou loi de kohlrausch. Le traitement des donnees montre que le transport est dispersif et l'existence d'etats localises sous la bande de conduction. De ces resultats, nous avons construit un modele fonde sur la chimisorption des gaz residuels dans les lacunes d'oxygene de la surface des cristallites. Les recombinaisons sont gouvernees par la diffusion dispersive des lacunes distribuees aleatoirement, qui se comportent comme des pieges a electron. Les charges se deplacent par une succession de sauts et de pauses jusqu'a recombinaison. Le modele a permis de simuler les variations anomales du temps de relaxation avec la temperature et la pression. Dans le ppv, la relaxation lente apparait en presence de traces d'air et a haute temperature. L'analyse des declins du photocourant entre 300 et 160 k montre que le transport est dispersif. En dessous de 160k, la relaxation lente est gelee et laisse place a un photocourant a cinetique rapide. La variation du signal en fonction de la puissance lumineuse, differente a haute et a basse temperature, implique qu'il existe deux processus distincts de creation des porteurs de charge. Notre modele suggere la photogeneration d'excitons et de paires interchaines de polaron. Une partie des paires se dissocient lentement par interaction avec des defauts electronegatifs extrinseques et les polarons positifs liberes suivent une diffusion dispersive, dans un reseau de defauts charges negativement. Les excitons, quant a eux, se dissocient rapidement grace au desordre intrinseque present dans le polymere.
9
von, Irmer Jonas. "Suzuki-Polykondensation hochmolekularer Poly-para-phenylene mittels Mikrowellenstrahlung." Phd thesis, 2021. https://tuprints.ulb.tu-darmstadt.de/11876/1/Dissertation_Jonas_von_Irmer.pdf.
Abstract:
Die Suzuki-Polykondensation (SPC) von Poly-para-phenylenen (PPP) wird durch ein besonders zeiteffizientes Syntheseprotokoll unter Verwendung von Mikrowellen-Erwärmung weiterentwickelt. Mehrzähnige Dendrimer- sowie Polymer-basierte Phosphin-Palladium-Komplexe werden entwickelt und als Katalysatoren in der Mikrowellen-SPC eingesetzt, um ein Kettenwachstumsmechanismus zu induzieren. Erstmals wird die Katalysatortransfer Polymerisation (CTP) unter Mikrowellen-Erwärmung durchgeführt und liefert dabei besonders hochmolekulare Produkte, welche mittels MALDI-TOF untersucht werden, um das Ablaufen nach einem Kettenwachstums-Mechanismus zu beweisen.
10
Mao, Guomin. "Strucutral studies of alkali-metal intercalated poly(para-phenylene-vinylene)." 1997. http://catalog.hathitrust.org/api/volumes/oclc/40058651.html.
Abstract:
Thesis (Ph. D.)--University of Wisconsin--Madison, 1997.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 179-189).
11
Wright, T. M., C. M. Carr, Colin A. Grant, V. Lilladhar, and S. J. Russell. "Strength of hydroentangled fabrics manufactured from photo-irradiated poly para-phenylene terephthalamide (PPTA) fibres." 2014. http://hdl.handle.net/10454/7413.
Abstract:
NoPhoto-irradiation of poly para-phenylene terephthalamide (PPTA) fibre is normally associated with deterioration of physical properties. Nonwoven fabrics produced from 100% photo-irradiated PPTA fibres might therefore be expected to yield fabrics with poorer mechanical properties compared to those produced from non-irradiated fibres. To test this hypothesis, the bursting strength of hydroentangled fabrics manufactured from photo-irradiated PPTA fibres was explored. Prior to fabric manufacture, virgin PPTA staple fibres were photo-irradiated under controlled lighting conditions (xenon short arc lamp with a luminous flux of 13,000 lm) for 0, 5, 10, 20, 40, 60 and 100 h. The photo-irradiated fibres were then hydroentangled to produce nonwoven fabrics. Photo-irradiation exposure of PPTA fibre up to 30 MJ m 2 was not found to be detrimental to fabric bursting strength and at irradiation energies of 5e10 MJ m 2 a small, but statistically significant increase in fabric bursting strength was observed compared to fabrics manufactured from non-irradiated fibre. This may be linked to a change in the surface and skin properties of the PPTA photo-irradiated fibres identified by atomic force microscopy (AFM) following photoirradiation.
12
Lee, Kang-hwa, and 李康華. "The Synthesis of 2-Oligo-(para-Phenylene-(E)-Vinylene) Substituted-3,4-Fullero-N-Methylpyrrolidine." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/50156526241062032591.
13
Li, Kang Hua, and 李康華. "The synthesis of 2-oligo(para-phenylene-(E)-vinylene)substituted-3,4-fullero-N-methylpyrrolidine." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/24578476845824958746.
14
Vetrichelvan, Muthalagu, and Suresh Valiyaveettil. "Molecular Engineering of Conjugated Polymers for Sensor Applications." 2005. http://hdl.handle.net/1721.1/30389.
Abstract:
In recent years, the application of fluorescent conjugated polymers for sensing chemical and biological analytes has received much attention from many researchers. A promising development in this direction was the fabrication of conducting polymer-based sensors for the detection of metal ions, small organic molecules and biomolecules. Herein, we have designed, synthesized and studied a series of copolymers containing alternate phenylene and 2,5- or 2,6-substituted pyridine rings. The basic N-atom of the pyridine ring and the adjacent –OH group from the phenyl ring provide binding sites for metal ions. Another series of water-soluble conjugated polymers with propoxy sulfonate side chains are investigated for biosensor applications. Significant quenching of the polymer fluorescence upon addition of viologen derivatives was also observed. The quenching effect on the polymer fluorescence confirmed that the newly synthesized polymers can be useful in the application of metal and biological sensors.Singapore-MIT Alliance (SMA)
15
Kankate, Laxman [Verfasser]. "Light emitting organic nanofibers from para-phenylene and α-thiophene [alpha-thiophene] oligomers / von Laxman Kankate." 2008. http://d-nb.info/989786188/34.
16
Vetrichelvan, Muthalagu, and Suresh Valiyaveettil. "Molecular Engineering of Amphiphilic Pyridine Incorporated Conjugated Polymers for Metal Ion Sensors." 2003. http://hdl.handle.net/1721.1/3934.
Abstract:
Recent developments in the synthesis and structure-property investigation studies of conjugated polymers have led to the design of novel polymeric materials with tailored properties for advanced technological applications. A promising development in this direction involves the fabrication of conducting polymer based sensors for the detection of metal ions and small organic molecules. Herein, we designed, synthesized and studied a series of amphiphilic copolymers containing alternate phenylene and 2,5- or 2,6- or 3,5-substituted pyridine rings. The basic N-atom of the pyridine ring and the adjacent –OH group from the phenyl ring provide binding sites for metal ions. Thermal properties, and optical properties of polymers in presence of acid, base and metal ions are investigated. A few target polymers showed high sensitivities for metal ions in solution.Singapore-MIT Alliance (SMA)
17
Anusooya, Y. "Properties Of The Correlated Electronic States In Conjugated Organic Molecules, Polymers And Metal-Halogen Chains." Thesis, 1996. http://etd.iisc.ernet.in/handle/2005/1943.
18
Hsu, Che-Hung, and 許喆閎. "The Optical and Electronic Properties of Conjugated Polymer(ladder-type poly para-phenylene) Ph-LPPP under Hydrostatic Pressures." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/79650655752842613270.
Abstract:
博士淡江大學
物理學系博士班
102
The optical properties, such as absorption, photoluminescence, photo-modulation and Raman scattering spectra, of blue light-emitting organic conjugated polymer, ladder-type poly(para-phenylene) (Ph-LPPP) with trace-concentration of metallic impurities, both in the powder form and in film form under various pressures were measured. Red-shift and broadening effects were found in all spectra with increasing pressure. Due to the pi-pi* character of conjugated polymers, the distance between bonds decreasing under pressure made the energy gap smaller resulting in the red shifts of spectra. Besides, the aggregates would affect the interfering between electronic clouds, such that the inter-chain coupling was stronger and resulted in the broadening of all spectra of polymer. The lifetimes of the triplet excitions and the photo-bleaching were also reported. The planarization of Ph-LPPP under pressure was discovered through all spectral features, which increases the intermolecular interaction, therefore, the effective conjugated length of the polymer, and causes the delocalization of triplet state. Through this work, we could understand the relationship between the singlet and triplet transitions, as well as the vibronic properties, of Ph-LPPP and its effective conjugated length.
19
Hsieh, Dung-Ting, and 謝東廷. "Novel Synthetic Approach to Oligo-(Para-Phenylene-(E)-Vinylene) s and Studies on Synthesis of Oligo[(Silanylene)Furan]s." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/58580906477002650832.
20
Hsiao, An-En, and 蕭安恩. "Studies of poly(para-phenylene)s on their structures and properties relationships and of characterization on conformation of single conjugated polymer chain." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/72030730780546300434.
Abstract:
碩士國立清華大學
化學工程學系
95
My study includes two following parts. The first is to improve Yamamoto polycondensation to yield high molecular weight poly(para-phenylene)s (PPPs) and to characterize their properties. PPPs are one of the most important classes of conjugated polymers and have been the subject of extensive research, particularly as active materials for use in light-emitting diodes (LEDs) and solar cell. These materials have been particular interest as potential blue emitters in such devices. The two main polycondensation methods used are the Suzuki polycondensation of aryl halides with arylboronic acids and the Yamamoto polymerisation of aryl dihalides using nickel(0) reagents. Generally speaking, the Suzuki method yield higher molecular weight than the Yamamoto procedure, but is synthetically more demanding (refer to arylboronic acids). To improve Yamamoto method, Using THF as reaction solvent to substitute for DMF and toluene used in common Yamamoto polycondensation, the reaction reactivity can be increased resulting from good solubility for both Ni catalysts and polymers. We can obtain high-molecular weight PPP as Suzuki polycondensation did. Then we synthesize three high-molecular weight PPP derivatives: mono-substituted alkoxyl group (mR8O-PPP), di-substituted alkoxyl group (dR8O-PPP), and Cz capping on the ends of alkoxyl group (Cz-PPP), and to study their structure-property relationships. The incorporation of long alkyl-chain substitute on side chain can pack in order in thin film as cast from THF and thus increase conjugation; Cz on the ends of alkoxyl group for Cz-PPP can destroy the order pack in thin film and thus reduces conjugation. While doping with 8 wt% Ir-G complex, Cz-PPP has less phase separation because the Cz on the ends of alkoxyl group exhibits excellent chemical compatibility with guest material. The device (ITO/PEDOT/Polymer : dopant /CsF/Ca/Al) based on this material exhibits stable green emission (spectrum remains unchanged upon successive operation) and luminous efficiency of 14.31 cd/A (13.6 V, 0.85 mA/cm2), and the highest luminance of 3882 cd/m2 (24.8 V , 107.6 mA/cm2). And we can obtain better balance of carrier by inserting TPBI as hole-blocking layer. The second is to determine the conformation of single conjugated polymer chain. A technique for grafting a polymer to a solid metal or semiconductor surface is essential for the development of such applications. This is because the chemical and electrical connectivity between a polymer terminus and an electrode surface may have an important influence on effective electron or photon signal transportation. A high density polymer grafted on a surface is commonly called a polymer brush, and such polymers have been well investigated such as surface modification. In contrast, a low-density grafted polymer is useful for observing nanostructures and physical properties at a single polymer chain level. As a methodology for polymer grafting, we use two-phase (water-toluene) reduction of AuCl4- by sodium borohydride in the presence of an alkanethiol, the gold particles of average 2.6 nm diameters bearing a surface of thiol have been prepared and characterized by TEM and UV-Vis absorption. Then we synthesized end-functionalized PFO bearing thiolacetate (SH-PFO). Furthermore, with the chemisorption of thiolacetate modified polymer on a gold particle surface, we visualized the polymer connection onto particle surfaces by AFM and clearly observed dumbbells-type nanohybrids that consisted of the polymer bridging between two Au nanoparticles.
21
Liou, Jia-Chie, and 劉家齊. "(1) Novel Synthetic Approaches to Alkoxy-Substituted Oligo-( para -Phenylene-(E)-Vinylene)s (2) S,S-Dimethyl Dithiocarbonate, A Novel Reagent For Polyurea Synthesis." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/80341996920888660361.
22
Lee, Chin-Sheng, and 李進勝. "Synthesis and Physical Properties of Conjugated Oxadiazole-Substituted Poly(Para-Phenylene-2,7- Fluorene), and the Thermofluoric Behavior of Poly(fluorenetolyldiphenylamine)-Oxadiazole Pair in Polymer Matrix." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/87577683838000775570.
Abstract:
博士國立臺灣大學
化學研究所
101
We use oxadiazole as the main core to construct two systems in this thesis. The first system to construct oxadiazole small molecules and polymer with side chains of oxadiazole. The second system to construct of oxadiazole with fluorene copolymer. These molecules are identified by fluorescence and cyclic voltammetry to understand the molecular conformation and its special physical properties. In additon, we synthesized two compounds. One contains oxadiazole groups, the other includes triphenylamine and fluorene. We found exciplex in two compound combination in solid phase. It does not form exciplex when phase separation in this combination and polymer matrix at room temperature. By controlling the temperature can be observed exciplex phenomena. By using fluorescence and surface analysis methods to understand the formation mechanism of exciplex.
23
Shaibu, Balagopal Shainamma, and 雪布. "PtII and RuII Catalyzed Regio-Controlled Synthesis of Ethylene-Bridged para-Phenylene Oligomers, Their Photophysical and Redox properties & Gold Catalyzed / Metal free Organic Transformations." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/01092102341825586951.
Abstract:
博士國立清華大學
化學系
100
本篇論文可分為四個章節，第一章節為合成一系列線形多苯環化合物且於分子之頭尾兩端接上二苯胺分子，並進一步測量以及探討其特殊的光物理以及電化學性質。第二以及第三章節主要利用金金屬錯合物催化 ynamides 分子進行[2+2+2] 環化加成反應以及利用碳烯分子進行交叉耦合反應合成一系列二烯類化合物。最後第四章節利用苯炔化合物、氧化胺以及炔分子進行多化合物組成反應合成一系列苯基吡啶化合物。 第一章節我們利用了不同的金屬錯合物催化具有高度位向選擇性之環化反應，將線型對苯化合物以乙烯分子橋接起來，並於兩端引入了二苯胺分子合成了一系列不同長度的線形多苯環分子。經由測量其HOMO、LUMO、UV吸收光譜、 螢光放射光譜 以及量子產率，實驗中發現此系列分子具有特殊的光物理以及電化學性質。 第二章節中我們開發了新型的金金屬錯合物催化芳酰胺分子以及烯醚化合物進行[2+2+2] 環化加成反應，值得注意的是此類新型反應並沒有觀察到任何分子內反應發生，可以利用於合成一系列的環己烷化合物。 第三章節我們發展了利用炔酯類分子進行重排反應以及重氮烷基碳烯產生乙烯基碳烯再經由金金屬錯合物催化交叉耦合反應。 最後一個章節我們利用了苯炔化合物、氧化胺以及炔分子進行多化合物組成反應合成一系列苯基吡啶化合物。