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dc.contributor.advisorSwarts, J. C.
dc.contributor.authorVon Eschwege, Karel Grobler
dc.date.accessioned2018-09-14T09:41:41Z
dc.date.available2018-09-14T09:41:41Z
dc.date.issued2006-01
dc.identifier.urihttp://hdl.handle.net/11660/9297
dc.description.abstractEnglish: A series of dithizones were synthesised, including its oxidation products, and the S-methylated and phenyl halogenated derivatives. Phenylmercury(II) complexes have been prepared from all these dithizonate ligands, while cobalt(III) and tin(IV) complexes were prepared from dithizone alone. X-ray crystal structure determinations were performed on the latter two complexes, revealing valuable information with regard to coordination number, π-conjugation patterns along the dithizonate backbone, and coordination bond strengths. A bi-metallic cobalt-mercury-dithizonate complex was for the first time identified, illustrating reversible coupling between the mercury dithizonate complex and cobalt. The lypophilic polymer, polyepichlorohydrin, and a hydrophilic polymer, a morpholine derivative of polysuccinimide, were synthesised. Both polymers, as well as dithizonatophenylmercury(II), PhHgHDz, were suitably functionalised to allow successful coupling of the photochromic compound, PhHgHDz, on both polymers. PhHgHDz remained photochromic in the lypophilic polymer, but not in the hydrophilic polymer. A series of porphyrins were synthesised, including tetraphenyl-, tetra(sodium 4-sulfophenyl)-, tetra(sodium 4-carboxyphenyl)-, tetraferrocenyl- and octaethylporphyrin. Apart from the ferrocenyl derivative, cobalt(II) and cobalt(III) complexes were prepared from all these porphyrins, while copper(II) complexes were prepared from tetraphenyl- and octaethylporphyrin. Interactions between the cobalt porphyrins and the above-mentioned dithizone derivatives were extensively studied by means of UV /visible spectroscopy. This revealed the redox nature often encountered in these complexes. Extensive ADF and Gaussian quantum chemical computations were done on dithizone, dithizonatophenylmercury(II) and its S-methylated derivative. Results highlighted the most probable structures of these compounds. The photochromic mechanism of PhHgHDz and its orbitals and transition energies involved, were also clarified. Computations on the adduct of the orange and blue isomers of PhHgHDz with cobalt porphyrin revealed results that were consistent with the expectation that the blue form might be at least as stable (or more stable) than the orange form. Electrochemical elucidation of the redox behaviour of dithizone, its derivatives, and mercury(II) and cobalt(III) complexes were researched for the first time. The relative resistance of the halogenated dithizones against oxidation was compared. Cobalt complexes of octaethyl-, tetraphenyl- and its sulfophenyl porphyrin derivatives were also electrochemically investigated, and there resistance against reduction compared. A comparative solvent study on the electrochemical behaviour of the substrate was performed, utilizing dimethylsulfoxide, dichloromethane and pyridine. The effect of supporting electrolyte on the electrochemical behaviour of dithizone and porphyrin derivatives was investigated, utilizing [NBu4][PF6] and [NBu4][B(C6F5)4].en_ZA
dc.description.abstractAfrikaans: 'n Reeks ditisone is gesintetiseer, insluitend ditisoon se oksidasieprodukte, en die S-gemetileerde en feniel gehalogeneerde derivate. Fenielkwik(II)komplekse van al hierdie ditisoonligande is berei, terwyI kobalt(III)- en tin(IV)komplekse van ditisoon alleen berei is. X-straalkristalstruktuurbepalings wat op laasgenoemde twee komplekse gedoen is, het waardevolle inligting rakende kotirdinasiegetal, π-konjugasie-patrone langs die ditisoonruggraat, en kotirdinasiebindingssterktes gegee. 'n Bi-metalliese kobalt-kwik-ditisoon kompleks is vir die eerste keer geïdentifiseer, wat omkeerbare koppeling tussen diekwik-ditisoon-kompleks en kobalt geopenbaar het. Die lipofiliese polimeer, poliepichlorohidrien, en 'n hidrofiliese polimeer, 'n morfolienderivaat van polisuksinimied, is gesintetiseer. Beide polimere, sowel as ditisonatofenielkwik(II), PhHgHDz, is sodaning gefunksionaliseer dat suksesvolle koppeling tussen die fotochromiese verbinding, PhHgHDz, en beide polimere bewerkstellig is. PhHgHDz was steeds fotochromies in die lipofiliese polimeer, maar nie in die hidrofiliese polimeer nie. 'n Reeks porfiriene is ook gesintetiseer, insluitend die tetrafeniel-, tetra(natrium 4-sulfofeniel)-, tetra(natrium 4-karboksiefeniel)-, tetraferroseniel- en oktaetielporfiriene. Behalwe Vir die ferrosenielderivaat is kobalt(Il)- en kobalt(III)komplekse van al hierdie porfiriene berei, terwyl koper(II)komplekse berei is met tetrafeniel- en oktaetielporfirien. Interaksies tussen kobaltporfiriene en bogenoemde ditisoonderivate is deeglik ondersoek met behulp van UV /sigbare spektroskopie. Hierdeur is die redokskarakter wat dikwels in hierdie komplekse voorkom, geopenbaar. Uitgebreide ADF en Gaussiese kwantumchemiese berekenings is uitgevoer op ditisoon, ditisonatofenielkwik(Il) en die S-gemetileerde derivaat. Resultate het die mees waarskynlike strukture van hierdie verbindings uitgewys. Die fotochromiese reaksiemeganisme van PhHgHDz, die orbitale en oorgangsenergiee betrokke was is ook opgeklaar. Rekenaarberekenings op die addukte van die oranje en blou isomere van PhHgHDz met kobaltporfirien was in ooreenstemming met die verwagting dat die blou vorm minstens net so stabiel, (of stabieler) as die oranje vorm sal wees. Elektrochemiese toeligting met betrekking tot die redoksgedrag van ditisoon, sy derivate, en kwik(II)- en kobalt(III)komplekse is vir die eerste keer nagevors. Die relatiewe weerstand van die gehalogeneerde ditisone teen oksidasie is vergelyk. Kobaltkomplekse van oktaetiel-, tetrafeniel- en die sulfofenielporfirien derivate is elektrochemies ondersoek, en hulle weerstand teen reduksie onderling vergelyk. 'n Vergelykende oplosmiddelstudie op die elektrochemiese gedrag van die substraat is met behulp van dimetielsulfoksied, dichlorometaan en piridien uitgevoer. Die effek van die hulpelektroliet op die elektrochemiese gedrag van ditisoon en porfirienderivate is met behulp van [NBu4][PF6] en [NBu4][B(C6F5)4] nagevors.en_ZA
dc.description.sponsorshipNational Research Foundation (NRF)en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectLiquid metalsen_ZA
dc.subjectMercury compoundsen_ZA
dc.subjectThesis (Ph.D. (Chemistry))--University of the Free State, 2006en_ZA
dc.titleStructural, electrochemical and optical properties of new cobalt porphyrin, tin and photochromic mercury complexes containing the dithizonato liganden_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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