Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: In an attempt to produce active catalysts for the oxidation of alkanes, hydrophobic dendritic micelle encapsulated gold nanoparticles were prepared. Dendrimers are well suited as templates for the encapsulation of metal nanoparticles as they can control the size and distribution of the particles. Using hydrophobic dendritic micelles it was found that the mode of encapsulation is driven by the solubility of the metal ions and not complexation of these ions, as is the case with conventional dendrimers. The dendritic micelles also provide the possibility of producing the dendrimer encapsulated nanoparticles in organic solvents, simplifying the encapsulation process as well as their subsequent application in catalysis. With this in mind, two types of dendritic micelles were synthesized. The first type, based on commercially available DAB PPI dendrimers, contained a diaminobutane core while the second type, containing a PAMAM interior architecture, has a cyclam core. Three generations of DAB PPI dendrimers were modified on their periphery with palmitoyl chloride to give the alkyl chain terminated hydrophobic DAB PPI dendritic micelles. The PAMAM-type cyclam-cored dendrimers were synthesized from the core outwards to produce two generations of cyclam-cored amine-terminated dendrimers. Their periphery could then be modified with palmitoyl chloride to produce two generations of alkyl chain terminated hydrophobic cyclam-cored dendritic micelles. The dendritic micelles were used as templates for the encapsulation of gold nanoparticles and these were fully characterized by UV/Vis spectroscopy and HR-TEM. Au13, Au31 and Au55 nanoparticles were encapsulated in each dendrimer template by varying the dendrimer to gold ratio. HR-TEM results indicate relatively uniform particles with an average particle size falling in the range of 4-6 nm. Finally, the dendrimer encapsulated nanoparticles (DENs) were applied as catalysts in the oxidation of n-octane. To the best of our knowledge DENs have not been applied as catalysts in the oxidation of linear alkanes. High substrate conversions, falling in the range of 70-90%, were achieved with all of the catalysts. Longer reaction times and lower catalyst loadings resulted in higher conversions with the optimum condition determined to be 0.1 mol% catalyst and 72 hours reaction time. It was also concluded that the nanoparticle size has a bigger influence on the conversion than the nature and generation of the dendrimer template. Overall the gold DENs show great potential as oxidation catalysts. / AFRIKAANSE OPSOMMING: In die poging om aktiewe katalisators vir die oksidasie van alkane te produseer is goud nanopartikels in die binne ruimtes van hidrofobiese dendritiese miselle ge-enkapsuleer. Dendrimere is geskikte template vir die enkapsulering van metaal nanopartikels a.g.v die feit dat dit die grootte en distribusie van die partikels kan beheer. Deur gebruik te maak van hidrofobiese dendritiese miselle verander die wyse van enkapsulering van kompleksering van metaal ione (die geval in konvensionele dendrimere) na oplossing gedrewe enkapsulering. Dendritiese miselle bied ook die moontlikheid om die dendrimer-ge-enkapsuleerde nanopartikels in organiese oplosmiddels voor te berei wat die enkapsulerings proses sowel as die toepassing in katalise vergemaklik. Met hierdie in gedagte is twee verskillende tipe dendritiese miselle gesintetiseer. Die eerste tipe, gebasseer op kommersieel beskikbare DAB PPI dendrimere, bevat ‘n diaminobutaan kern, terwyl die tweede tipe, bestaande uit ‘n PAMAM binne-struktuur, ‘n siklaam kern bevat. Drie generasies van DAB PPI dendrimere was gemodifieer op die periferie met palmitoïelchloried om alkiel ketting getermineerde hidrofobiese DAB PPI dendritiese miselle te produseer. Die PAMAM siklaam kern bevattende dendrimere was gesintetiseer van die kern uitwaarts om twee generasies amien getermineerde dendrimere te produseer. Dit was toe moontlik om die periferie met palmitoïelchloried te modifieer om twee generasies van alkiel getermineerde siklaam kern bevattende hidrofobiese dendritiese miselle op te lewer. Die dendritiese miselle was gebruik as template vir die enkapsulasie van goud nanopartikels en volledig gekarakteriseer deur UV/Vis spektroskopie en HR-TEM. Au13, Au31 and Au55 nanopartikels was ge-enkapsuleer in elk van die dendrimeer template deur die verhouding van dendrimeer tot goud te wissel. HR-TEM resultate dui aan dat die partikels goed versprei is met ‘n gemiddelde partikel grootte tussen 4-6 nm. Die dendrimeer ge-enkapsuleerde goud nanopartikels (DENs) was as katalisators in die oksidasie van n-oktaan toegepas. Volgens ons kennis is DENs nog nie toegepas as katalisators in die oksidasie van lineêre alkane nie. Hoë substraat omskakelings, tussen 70 en 90%, was deur al die katalisators bereik. ‘n Langer reaksie tyd en laer katalisator konsentrasies het hoër omsettings tot gevolg gehad. Die optimale kondisies sluit ‘n 0.1 mol% katalisator konsentrasie en 72 uur reaksie tyd in. Die gevolgtrekking was gemaak dat die nanopartikel grootte ‘n groter invloed op die substraat omsetting het as die aard en generasie van die dendrimeer templaat. Alles in ag geneem, wys die goud DENs groot potensiaal as oksidasie katalisators.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This project entailed the synthesis and characterization of mono- and multi-nuclear rhodium and ruthenium iminopyridyl complexes and their application in the hydroformylation of 1- octene. The multi-nuclear complexes were synthesized in order to investigate whether it could produce catalysts with higher activity than their mononuclear analogues. Four novel iminopyridyl ligands, ranging from mono- to tetra-functional compounds, were synthesized. The synthesis was a two-step process initially involving a Schiff base condensation reaction between 2-pyridinecarboxaldehyde and 4-aminophenol to produce a hydroxy functionalized pyridine-imine. The latter was then subjected to a nucleophilic substitution reaction with an appropriate benzyl bromide derivative to yield the target ligands. All these ligands were isolated in moderate to good yields and characterized using a range of analytical techniques. These ligands, together with the hydroxy functionalized pyridine imine, were then complexed to both Rh(I) and Ru(II) metal precursors, yielding ten novel metal complexes. The characterization of some of the complexes, especially the multi-nuclear complexes, were slightly more difficult due to their low solubility. However, all these complexes could be isolated in good to high yields as stable green-brown (in the case of Rh(I)) and yellow-orange (in the case of Ru(II)) solids. Finally, these complexes were applied as catalyst precursors in the hydroformylation of 1- octene. In the case of the Rh(I) complexes, relatively high activities were observed, with conversions ranging between 50 – 90 % in all cases, when tested at 30 bar, 75 °C and a 0.05 mol% catalyst loading. The activity was found to increase when going from the mono- to the bi-nuclear catalyst. However, solubility in the reaction medium was a major issue for the trinuclear catalyst, as it contributed to the lower activity observed. High chemoselectivity towards aldehydes was observed for all catalysts, which increased with reaction times. During shorter reaction time, linear regioselectivity was also relatively high. This however, decreased with increasing reaction time as the internal octenes formed initially, were converted to branched aldehydes. When the Ru(II) complexes were tested under the same conditions as the Rh(I) complexes, very low activity was observed. Under more stringent conditions (45 bar, 120 °C, 0.5 mol%) the ruthenium catalysts performed relatively well, compared to other complexes in the literature. The same trend in terms of the chemo- and regioselectivity for the Ru(II) complexes were observed. The Rh(I) complexes were far more active than the Ru(II) complexes. / AFRIKAANSE OPSOMMING: Hierdie projek behels die sintese en karakterisering van mono- en multi-kernige rhodium en ruthenium iminopiridiel komplekse en hul toepassing in the hidroformulering van 1-okteen. Die multi-kernige komplekse is gesintetiseer met die doel om vas te stel of hulle katalisatore wat meer aktief is as hul monokernige eweknieë, kan produseer. Vier nuwe iminopiridiel ligande, wat strek vanaf mono- tot tetra-funksionele verbindings, is gesintetiseer. Die sintese was ‘n twee-stap proses wat aanvanklik ‘n Schiff basis kondensasie reaksie tussen 2-piridienaldehied en 4-aminofenol behels, om ‘n fenol gefunksioneerde piridien-imien te vorm. Die laasgenoemde was gevolglik aan ‘n nukleofiliese substitusie reaksie met ‘n gepaste bensiel bromied derivaat onderhewig. Al hierdie ligande is geisoleer in matige tot goeie opbrengste en gekarakteriseer met ‘n reeks analitiese tegnieke. Hierdie ligande, tesame met die fenol gefunksioneerde piridien imien, is dan met Rh(I) en Ru(II) metaal uitgangstowwe gekomplekseer, wat tien nuwe metaal komplekse tot gevolg gehad het. Die karakterisering van sommige van die kompekse, spesifiek die multi-kernige komplekse, was effens moeiliker as gevolg van hul swak oplosbaarheid. Al hierdie komplekse kon egter in goeie tot hoë opbrengste as stabiele groen-bruin (in die geval van Rh(I)) en geel-oranje (in die geval van Ru(II)) vastestowwe geisoleer word. Laastens is die komplekse as katalisator-voorlopers in die hidroformulering van 1-okteen gebruik. In die geval van die Rh(I) komplekse is redelike hoë aktiwiteite waargeneem, met omsettings tussen 50 – 90 % in alle gevalle, wanneer hulle by 30 bar, 75 °C en ‘n katalisator lading van 0.05 mol% getoets is. Die aktiwiteit neem toe vanaf die mono- na die bi-kernige katalisator. Oplosbaarheid in die reaksie medium was egter ‘n probleem vir die tri-kernige katalisator, wat ‘n laer aktiwiteit tot gevolg gehad het. Hoë chemoselektiwiteit na aldehiede is waargeneem vir al die katalisatore en dit neem toe met reaksietyd. Gedurende korter reaksietye was die liniêre regioselektiwiteit ook redelik hoog, maar neem af met toenemende reaksietyd soos die interne okteen wat aanvanklik vorm na vertakte aldehiede omgeskakel word. Toe die Ru(II) komplekse onder dieselfde toestande as die Rh(I) komplekse getoets is, was baie lae aktiwiteite waargeneem. Onder hoër temperatuur en druk (45 bar, 120 °C, 0.5 mol%) toon die ruthenium katalisatore redelik goeie aktiwiteite in vergelyking met ander komplekse wat in die literatuur gerapporteer is. Dieselfde tendense in terme van die chemoen regioselektiwiteit is vir die Ru(II) komplekse waargeneem. Die Rh(I) kompleks was baie meer aktief as die Ru(II) komplekse.

Keung, Yiu Cheung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 58-59). / Abstracts in English and Chinese. / Contents --- p.i / Acknowledgement --- p.iii / Abstract --- p.iv / Abbreviations and Acronyms --- p.vi / Chapter Chapter 1 - --- Amphiphilic Dendrons and Gene Transfection / Chapter 1.1 --- Introduction to Dendrimers and Gene Transfection --- p.1 / Chapter 1.2 --- Overview of Gene Transfection Vectors in the Literature --- p.4 / Chapter 1.2.1 --- Viral Vectors --- p.5 / Chapter 1.2.2 --- Non-viral Vectors --- p.5 / Chapter 1.2.2.1 --- Cationic Lipids --- p.6 / Chapter 1.2.2.2 --- Cationic Polymers --- p.7 / Chapter 1.2.2.3 --- Cationic Dendrimers --- p.8 / Chapter Chapter 2 - --- En Route to Dendritic Amphiphilic Vectors / Chapter 2.1 --- Introduction to the Design of Dendritic Amphiphiles --- p.13 / Chapter 2.2 --- Barriers to Gene Transfection --- p.13 / Chapter 2.2.1 --- Cellular Barriers --- p.14 / Chapter 2.2.2 --- Extracellular Barriers --- p.16 / Chapter 2.2.3 --- Material Design Considerations --- p.17 / Chapter 2.3 --- Amphiphilic Vector Design Strategy --- p.18 / Chapter 2.4 --- Summary --- p.21 / Chapter Chapter 3 - --- "Design, Synthesis and Structural Characterization of New Amphiphilic Dendrons for Gene Transfection" / Chapter 3.1 --- Design of the New Amphiphilic Dendrons . --- p.23 / Chapter 3.1.1 --- Incorporation of Hydrocarbon Dendrons --- p.24 / Chapter 3.1.2 --- Synthesis Feasibility --- p.24 / Chapter 3.2 --- Synthesis of the New Amphiphilic Dendrons --- p.25 / Chapter 3.3 --- Characterization of the Intermediates and Targeted Amphiphilic Dendrons --- p.28 / Chapter 3.3.1 --- 1H NMR Spectroscopy --- p.28 / Chapter 3.3.2 --- I3C NMR Spectroscopy --- p.30 / Chapter 3.3.3 --- Mass Spectrometry --- p.33 / Chapter 3.3.4 --- Critical Micelle Concentration --- p.35 / Chapter 3.4 --- Conclusion --- p.38 / Chapter Chapter 4 - --- Determination of Transfection Efficiency and Cytotoxicity / Chapter 4.1 --- Preparation of the Amphiphilic Dendrons for Transfection --- p.39 / Chapter 4.2 --- Transfection Efficiencies of the Amphiphilic Dendrons 1-10 --- p.39 / Chapter 4.3 --- Cytotoxicity Assay --- p.42 / Chapter 4.4 --- Conclusions --- p.44 / Chapter Chapter 5 - --- Experimental Procedures / Chapter 5.1 --- General Information --- p.46 / Chapter 5.2 --- Experimental Procedures --- p.47 / References --- p.58 / Appendix / NMR Spectra --- p.60

Choi, Lai Sheung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 111-115). / Abstracts in English and Chinese. / Contents --- p.i / Acknowledgements --- p.iv / Abstract --- p.v / Abbreviations --- p.viii / Chapter Chapter 1 - --- Introduction to Dendrimer / Chapter 1.1 --- Definition --- p.1 / Chapter 1.2 --- Synthetic Routes --- p.2 / Chapter 1.2.1 --- Divergent Growth --- p.2 / Chapter 1.2.2 --- Convergent Growth --- p.3 / Chapter 1.3 --- Applications --- p.4 / Chapter 1.4 --- Examples of Dendrimers --- p.6 / Chapter 1.4.1 --- Hydrocarbon Dendritic Species --- p.6 / Chapter 1.4.2 --- Aliphatic Polyether Dendritic Species --- p.8 / Chapter Chapter 2 - --- Synthesis of Novel Amphiphilic Hydrocarbon Dendrons / Chapter 2.1 --- Background - Hydrocarbon Dendrons (HCDs) --- p.11 / Chapter 2.2 --- Modification and Design of Synthetic Scheme --- p.13 / Chapter 2.3 --- Syntheses --- p.14 / Chapter 2.3.1 --- Convergent Synthesis --- p.14 / Chapter 2.3.2 --- Divergent Synthesis --- p.19 / Chapter 2.4 --- Characterizations --- p.22 / Chapter 2.4.1 --- 1H NMR Spectroscopy --- p.22 / Chapter 2.4.2 --- 13C NMR Spectroscopy --- p.25 / Chapter 2.4.3 --- Mass Spectrometry --- p.27 / Chapter 2.4.4 --- Gel Permeation Chromatography (GPC) --- p.29 / Chapter 2.4.5 --- Thin Layer Chromatography (TLC) --- p.31 / Chapter 2.4.6 --- Solubility --- p.31 / Chapter 2.5 --- Conclusions and Future Prospects --- p.33 / Chapter Chapter 3 - --- Hydrogen Bonding in Supramolecular Chemistry / Chapter 3.1 --- Background ´ؤ Supramolecular Chemistry --- p.35 / Chapter 3.1.1 --- Multiple Hydrogen Bondings --- p.37 / Chapter 3.1.2 --- Applications --- p.39 / Chapter 3.2 --- 2-Ureido-4[lH]-Pyrimidinone (UPy) --- p.40 / Chapter 3.2.1 --- Tautomerization and Dimerization Equilibria --- p.40 / Chapter 3.2.2 --- Examples of Dendronized UPy Dimers --- p.44 / Chapter 3.3 --- Effects of Substituents on the Dimerization Behavior of UPy --- p.46 / Chapter 3.4 --- Dimerization Studies on Our New UPy-Dendrons --- p.50 / Chapter Chapter 4 - --- "Synthesis, Characterizations and Dimerization Properties of Dendronized UPy Dimers" / Chapter 4.1 --- Synthesis --- p.51 / Chapter 4.2 --- Characterizations --- p.51 / Chapter 4.2.1 --- 1H NMR Spectroscopy --- p.51 / Chapter 4.2.1.1 --- Dimerization Behavior of Protected UPy Series (94-97) in CDC13 at 25 °C --- p.52 / Chapter 4.2.1.2 --- Temperature-Dependent Behavior of Protected UPy Series (94´ؤ97) in CDC13 --- p.59 / Chapter 4.2.1.3 --- Tautomeric Behavior of Protected UPy Series in (94-97) in Other Solvents --- p.60 / Chapter 4.2.1.4 --- Characterization of Deprotected UPy Series (98-101) in DMSO-d6 --- p.60 / Chapter 4.2.1.5 --- Dimerization Behavior of Deprotected UPy Series (98-101) in THF-d8 and Other Solvents --- p.63 / Chapter 4.2.1.6 --- Temperature-Dependent Behavior of Deprotected UPy Series (98´ؤ101) in THF-d8 --- p.67 / Chapter 4.2.1.7 --- Dimerization Constants of Both Protected and Deprotected UPy Series in DMSO-d6/CDCl3 Mixtures at 25 °C --- p.68 / Chapter 4.2.2 --- 13C NMR Spectroscopy --- p.71 / Chapter 4.2.3 --- Mass Spectrometry --- p.71 / Chapter 4.2.4 --- Gel Permeation Chromatography (GPC) --- p.73 / Chapter 4.2.5 --- Vapour Pressure Osmometry (VPO) --- p.74 / Chapter 4.2.6 --- Infrared Spectroscopy --- p.75 / Chapter 4.2.7 --- Polarity and Solubility --- p.76 / Chapter 4.3 --- Conclusions --- p.77 / Chapter Chapter 5 - --- Conclusions --- p.79 / Chapter Chapter 6 - --- Experimantal Procedures / Chapter 6.1 --- General Information --- p.81 / Chapter 6.2 --- Experimantal Procedures --- p.82 / References --- p.111 / Appendix 1 - Calculations of lower-limits of Kdim* in CDCI3 --- p.A-1 / Appendix 2 - Calculations of Kdim* in systems where both dimer(s) and 6[1H] monomer coexist --- p.A-4 / Appendix 3 - List of Spectra --- p.A-5

Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 22, 2008) Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

A great number of pharmaceutical drugs target nucleic acids. However, drug-DNA interactions can be region non-specific and lead to undesired side effects. Understanding the mechanisms that regulate drug-DNA binding can help in the design of potent and selective therapeutic agents with fewer deleterious side effects. The present investigation explores the metal-mediated DNA binding of a group of 2-(2-hydroxyphenyl)benzoxazole (HPB) ligands and the aggregation dependant G-quadruplex selectivity of a series of perylene tetracarboxylic acid diimides (PTCDI) compounds. HPB ligands are simplified analogs of the bis-benzoxazole natural product UK-1. This compound is able to inhibit cell growth of various tumor cell lines, bind divalent cations, and interact with DNA in a metal dependant fashion. The HPB moiety present in UK-1 was identified as relevant for its metal ion binding and biological properties. For this work, novel HPB ligands were synthesized with different substitutions at the C4 or C7 position. Their ability to bind metal ions and DNA was evaluated and their cytotoxicity was assessed in multiple cancer cell lines. The ligands bound to Cu²⁺ with the highest affinity among metals studied. Consequently, Cu²⁺ promoted the most dramatic increase in DNA binding and affected the ligand's cellular cytotoxicity. The second project focused on targeting four-stranded structures called G-quadruplexes, which can form in G-rich nucleic acid sequences. Compounds that stabilize these structures may inhibit nucleic acid-processing enzymes such as telomerase and potentially act as anti-cancer agents. PIPER is a PTCDI that is particularly selective for G-quadruplex DNA versus duplex DNA under conditions in which it forms aggregates. This work investigated ligand aggregation in a series of PIPER analogs with different structural features under high and low salt buffers, changes in pH, metal binding and temperature changes. A negatively charged analog was determined to form metal-mediated aggregates while novel thermophilic mediated aggregation was discovered for an analog with methoxyethoxymethyl groups. The ability of these ligands to bind different DNA structures was evaluated under aggregating and non-aggregating conditions. This study supports the idea that ligand aggregation increases their quadruplex selectivity and decreases double-stranded DNA binding.

A range of highly ordered dendritic and oligomeric macromolecules, functionalised with tetrathiafulvalene (TTF) derivatives as a redox-active sub-unit were assembled. In particular, the first dendritic macromolecules incorporating TTF were constructed by the reaction of poly-acid chlorides and alcohol functionalities. Electrochemical techniques showed the novel redox-superstructures to be efficient π-electron donors that are able to undergo two reversible, multi-electron-on oxidations. The TTF-units were established to be acting independently, and the extent to which the redox groups could be oxidised was evaluated. UV studies demonstrated the redox- assemblies to be capable of forming charge-transfer complexes m solution and showed potential for the formation of conducting charge-transfer complexes. Preliminary studies showed the precursors to these compounds to be suitable for use as electrochemical detectors for dopamine. Structural variation of the core units increased the air and thermal stability of the dendritic materials, whilst retaining the characteristics of the multi-redox system. These systems formed stable aggregates of the radical cation and afforded conducting charge- transfer complexes with TCNQ. The new precursors to multi-TTF systems were then used in attempts to impart redox characteristics on [2]pseudorotaxanes and rotaxanes. Preliminary attempts were made to assemble multi-TTF systems using a TTF derivative as a core and at the periphery.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.