京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22702号 / 工博第4749号 / 新制||工||1742(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 大江 浩一, 教授 近藤 輝幸, 教授 中尾 佳亮 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

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Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2009. / Please refer to full text to view abstract.

Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2005. / In this study several potential polymerisation catalysts were synthesised. This was accomplished by coordinating α-diimine ligands such as N,N'-diferrocenyldiazabutadiene (DFDAB), N,N'-dimesityldiazabutadiene (DMDAB) as well as the bidentate amine N,N,N',N'-tetramethylethylenediamine (TMEDA), to several transition metals. The multi-step synthesis of N,N'-diferrocenyldiazabutadiene (DFDAB) from ferrocene involved the use of lithiated ferrocene, iodoferrocene, N-ferrocenylphthalimide and aminoferrocene; the latter three were characterised. This ligand was coordinated to the transition metal ions iron(II) and zinc(II) to form Fe(DFDAB)Cl2 and Zn(DFDAB)Cl2 respectively. 1H and 13C NMR, FT-IR and mass spectrometry revealed that the expected product had been synthesised in a useful form. 2,4,6-Trimethylaniline reacted with glyoxal to form N,N'-dimesityldiazabutadiene (DMDAB). The DMDAB ligand was coordinated to the transition metal ions zinc(II) and silver(I) to form Zn(DMDAB)Cl2 and Ag(DMDAB)2 respectively. Characterisation now also include molecular and crystallographic structural determinations by means of X-ray diffractometry. Another N-donor complex, Cr(CO)4(TMEDA), was also prepared by coordinating N,N,N',N'-tetramethyl ethylenediamine (TMEDA) to Cr(CO)5(THF). This was done to give an indication of the activity of low oxidation state complexes in the catalysis of olefin polymerisation. The metal-α-diimine complexes mentioned above were employed in the polymerisation of the monomers ethylene and 1-pentene probably according to a cationic mechanism. High density, high molar mass polyethylene products with narrow polydispersities were obtained. The chromium(TMEDA) complex produced polyethylene exhibiting ultra-high molar mass (> 10 000 kg/mol). The polymerisation of 1-pentene, using the Fe(DFDAB)Cl2 complex, afforded oligo-pentene with a molar mass of ~800 g/mol. After an unsuccessful attempt to prepare the (CO)5Cr=C(OZrCp2Cl)(ferrocenyl) modified Fischer-type carbene complex, the (CO)5Cr=C(OMe)(ferrocene) complex was eventually insolated. Elucidation of its molecular structure was accomplished by X-ray diffractometry. Finally, the DFDAB-ligand was coordinated to Fe2(CO)9 to generate Fe(CO)3(DFDAB) in another attempt to investigate the role of carbonyl groups and also low oxidation state metals in polymerisation reactions [compare to Cr(CO)4(TMEDA) unit above]. The sensitivity of this complex towards moisture and air prevented such action.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: see full text for abstract. / AFRIKAANSE OPSOMMING: Sien volteks vir die opsomming.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Please refer to fulltext for abstract / AFRIKAANSE OPSOMMING: Sien asb opsomming vir volteks

Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: A thorough search through the literature as well as through the Cambridge Crystallographic Structural Database resulted in no examples of a neutral ozone acting as ligand in a complex with any metal. Ionic compounds containing ozonide as anionic species, however, are well known throughout the literature and not surprisingly the only result for 0₃ and a metal in the CCSD was an ionic rubidium ozonide compound. What follows is a systematic study into the result of placing an ozone ligand within complexing distance of a transition metal (the first transition row from titanium to copper). Due to the novelty of the system, as first approximation four different orientations of the ozone ligand relative to the metal (a metal cation in these calculations) were investigated. It was found that coordination through the terminal oxygens resulted in energy minima for all the metal cations, although not necessarily the absolute energy minimum on the potential energy surface for the specific cation. A further structural study was done by adding carbonyl and hydrogen ligands to the system, according to the 18-electron rule. For these calculations coordination through the terminal oxygens was employed. In both series the dissociation energy was also calculated. The dissociation energies for the M(CO)nHm(0₃) complexes were all positive, indicating that they are theoretically stable structures. The resulting wave functions were then analysed with the help of three techniques: Atoms in Molecules (AIM), Charge Decomposition Analysis (CDA) and Natural Bond Orbital Analysis (NBO). AIM showed that bonds were indeed formed between the ozone ligand and the transition metal and hinted that the bonding model can be interpreted with the Dewar-Chatt-Duncanson (DCD) model of σ-donation and л-back donation. CDA confirmed that this was the case. NBO results proved erroneous due to the largely delocalized electronic structure of the complexes. / AFRIKAANSE OPSOMMING: 'n Deeglike soektog deur die literatuur en die Cambridge Crystallographic Structural Database het geen resultate gelewer van komplekse waarin 'n neutrale osoonligand komplekseer met 'n metaal nie. Ioniese verbindings waarin die osonied as anioon optree, is wel bekend deur die literatuur en die enigste resultaat in die CCSD - vir 'n soektog bevattende osoon en 'n metaal - het 'n rubidiumosonied-verbinding opgelewer. Wat volg is 'n stelselmatige studie om die effek te ondersoek indien 'n osoonligand naby genoeg aan 'n oorgangsmetaal geplaas word om kompleksering te bevoordeel (metale wat gebruik is, is die eerste oorgangsreeks vanaf titanium tot koper). As gevolg van die onbekendheid van die sisteem is vier verskillende oriëntasies van die osoonligand relatied tot die metal ('n metal katioon in die geval) as beginpunt ondersoek. Daar is gevind dat koordinasie deur die terminale suurstowwe van die osoonligand vir al die metal katione lei tot energie minima, alhoewel dié minima nie noodwendig die globale minima op die potensiële energie oppervlaktes van die katione is nie. 'n Verdere studie is gedoen deur karboniel- en waterstofligande tot die sisteem te voeg, gelei deur die 18-elektron reel. Vir hierdie berekeninge is koördinasie deur die terminale suurstowwe gebruik. In beide reeks is dissosiasie-energieë bereken. Die dissosiasie energieë van die M(CO)nHm(0₃) komplekse was deurgaan positief wat aandui dat die komplekse teoreties stabiel is. Die verkrygde golffunksies is hierna analiseer deur middel van drie tegnieke: Atoms in Molecules (AIM), Charge Decomposition Analysis (CDA) en Natural Bond Orbital Analysis (NBO). AIM het getoon dat bindings inderdaad gevorm word tussen die osoonligand en die metal en bet die moontlikheid laat ontstaan dat die bindingsmodel volgens die Dewar-Chatt-Duncason (DCD) model van σ-donasie en л-terugdonasie geïnterpreteer kan word. Hierdie waarneming is bevestig deur CDA. NBO resultate kon nie suksesvol gebruik word nie as gevolg van die hoë graad van electron delokalisasie van die komplekse.

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

Orientador: José Clayston Melo Pereira / Banca: Adelino Vieira de Godoy Netto / Banca: Gustavo Metzker / Resumo: O câncer é uma dos principais problemas de saúde que afeta e mata milhões de pessoas. Diversos tipos de tratamento já foram propostos, entretanto, alguns se apresentam muitas vezes tóxicos ao corpo e/ou ineficientes de acordo com as características particulares do organismo. Dentre as propostas de tratamento está o uso do complexo precursor [Fe(NO)2(CO)2] para síntese de complexos [Fe(NO)2 Ligante] em que se encontram a vanilina tiossemicarbazona (VTS) e a vanilina semicarbazona (VSC) como ligantes. Busca-se, por meio desses, a possibilidade de inibição do sistema enzimático da glutationa - glutationa / glutationa transferases - conhecido por restringir a ação da cisplatina através da catalisação da conjugação da glutationa com o complexo - e através do uso dos dinitrosilos de ferro (DNICs) e da liberação do ligante orgânico obter uma possível atuação farmacológica. Neste trabalho, foram utilizadas técnicas como Análise Elementar, Espectroscopia no UV-Vis, Espectroscopia no Infravermelho, Espectroscopia de Ressonância Magnética Nuclear, Ressonância Paramagnética de Elétron e Espectrometria de Massas para a caracterização dos ligantes que foram também avaliados por ensaio citotóxico frente a linhagem MCF-7 (adenocarcinoma mamário humano) e bacteriano por Staphylococcus aureus e Escherichia coli. Os complexos sintetizados foram avaliados por técnicas espectroscópicas e espectrometria de massas. / Abstract: Cancer is one of the major health problems that affects and kills millions of people. Several types of treatment have been proposed, however, some of them are often toxic to the body and / or inefficient according to the particular characteristics of the organism. Among the treatment proposals is the use of the precursor complex [Fe(NO)2(CO)2] for synthesis of complexes [Fe(NO)2Binder] in which are the vanillin thiosemicarbazone (VTS) and vanillin semicarbazone (VSC ) as ligands. The aim is to inhibit the enzymatic system of glutathione glutathione / glutathione transferases known to restrict the action of cisplatin by catalyzing the conjugation of glutathione to the complex and through the use of iron dinitrosilos (DNICs) and the release of the organic ligand to obtain a possible pharmacological action. In this project, were used techniques such as Elementary Analysis, UV-Vis Spectroscopy, Infrared Spectroscopy, Nuclear Magnetic Resonance Spectroscopy, Electron Paramagnetic Resonance and Mass Spectrometry for the characterization of ligands that were also evaluated by cytotoxic assay against the MCF lineage -7 (human mammary adenocarcinoma) and bacterial by Staphylococcus aureus and Escherichia coli. The synthesized complexes were evaluated by spectroscopic techniques and mass spectrometry. / Mestre

M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / Contamination of water bodies by heavy metals and metalloids is an established problem and several studies have been conducted to deal with it. South Africa is amongst those countries whose water systems are most affected as a result of intensive mining activities. This research was dedicated to the development of insoluble chelating polymers for use as adsorbents to abstract heavy metal ions from mining and industrial wastewater. Branched polyethylenimine (PEI), well known for its metal chelating potential, was cross linked by epichlorohydrin in order to convert it into a water-insoluble form. The water-insoluble property gives the advantage of being used in situ and a possibility of regeneration and re-use, making it a more feasible and cost-effective method. Its surface was also modified for selective removal of specifically-targeted heavy metal and metalloid ions. The binding affinity of the synthesized materials to heavy metal and metalloid ions has been determined as well as their ability to be regenerated for reuse. These processes demonstrated that cross-linked polyethylenimine (CPEI) exhibited good complexation ability with high affinity to Cr and some divalent metal ions such as Fe, Zn, and Ni. On the other hand, it showed very poor ability to bind oxo-anions such as SeO32- and AsO2- which has been attributed to the unavailability of suitable functional groups to interact with these ions. The observed order of complexation was: Cr > Zn> Fe >> Ni > Mn > Pb >> As > U > Se. The phosphonated polyethylenimine (PCPEI) showed high selectivity for As, Mn and uranyl ions. The observed order of removal was: U > Mn> Ni > Zn > As >> Cr > Pb > Fe >> Hg > Se; whereas the suffocated polyethylenimine (SCPEI) exhibited high affinity to Se, and Hg. The observed order of adsorption was: Hg > Se >> U > Zn >Pb > Ni >> As > Cr > Fe. v The adsorption behaviour of these polymeric materials involved more than one mechanism such as complexation, normal surface charge exchange, and anion replacement and all these mechanisms are governed by the functional groups. The nitrogen atom on the chelating group (-NH) in the cross-linked polyethylenimine; the phosphorus atom on the chelating group (-PO3H2) in phosphonated cross-linked polyethylenimine; and sulphur atom on the chelating group (-SO3H) in suffocated cross-linked polyethylenimine act as Lewis bases and donate electrons to metal cations which are considered Lewis acids. The existence of the chelating groups in SCPEI and PCPEI facilitate the removal of oxo-anions through anion replacement since they exist as bases in solution and hence cannot be electron acceptors. Thus, the expected mechanism is the normal anion replacement. This mechanism can explain the high removal of Se by SCPEI since Se has similar chemical behaviour as sulphur and are in the same group in the periodic table. As such they can easily replace each other. Sulphur is released from the polymer into the solution by replacing the selenium ions in the polymer. Similar behaviour occurs between phosphorus in PCPEI and arsenic ions as As and P belong to the same group in the periodic table and hence have similarities in their chemical behaviour. The Langmuir and Freundlich isotherm models were used to interpret the adsorption nature of the metal ions onto synthesized polymers. The Freundlich isotherm was found to best fit and describe the experimental data describing the adsorption process of metal and metalloid ions onto the synthesized polymeric materials The kinetic rates were modelled using the pseudo first-order equation and pseudo second-order equation. The pseudo second-order equation was found to explain the adsorption kinetics most effectively implying chemisorption. vi The thermodynamic study of the adsorption of metals and metalloids by the synthesized CPEI, PCPEI and SCPEI resulted in high activation energies > 41 KJ mol-1 which confirm chemisorption as a mechanism of interaction between adsorbate and adsorbent. So far, the developed polymeric materials showed good results and have potential to be applied successfully for remediation of heavy metal-polluted waters, and they have potential for use in filter systems for household use in communities that use borehole water impacted by mining and industrial waste waters. The desorbed metals can be of use to metal processing industries.