Studies with dithizone : the extraction of thallium (III)

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dc.contributor.advisorIrving, H M N Hen_ZA
dc.contributor.advisorKoch, Klaus Ren_ZA
dc.contributor.authorSacht, Cherylen_ZA
dc.date.accessioned2016-10-16T09:51:57Z
dc.date.available2016-10-16T09:51:57Z
dc.date.issued1985en_ZA
dc.descriptionBibliography: pages 141-144.en_ZA
dc.description.abstractThallium(III) reacts with dithizone(I) in a complicated way through a number of intermediate products which depend on the relative proportions of reactants, the pH of the aqueous phase, the order of mixing of reactants, the time of phase equilibrium and the nature of the organic solvent used. The reaction between thallium(III) and dithizone is essentially oxidative in character. In the present work the complete reaction scheme is proposed: Thallium(III) reacts with dithizone to give a thallic-dithizonate complex, [TlIII(HDz)₃], which spontaneously and oxidatively disproportionates to the disulphide (III) and a thallium(I)-dithizonate complex, [Tl(HDz)]. The disulphide(III) decomposes by first-order heterolytic fission to give equimolar amounts of dithizone and the mesoionic compound (IV) . The Tl(HDz) complex undergoes reversion to give Tl+ in the aqueous phase and dithizone in the organic phase. In the presence of excess thallium(III) the regenerated dithizone is oxidized to the mesoionic compound (IV): the mesoionic compound (IV), partitions between the two phases and appears to react with excess thallium(III) to give possibly a mesoionic compound (IV)-thallium(III) complex and an unspecified oxidation product. The molecular structure of the 1 : 1 adduct formed between diphenylthallium( III) and dithizone has been shown by single crystal X-ray diffraction, to be a five co-ordinate diphenylthallium(III) complex: the dithizone acts as a bidentate chelating ligand co-ordinating through the nitrogen and sulphur atoms. Ethanol (solvent of recrystallisation) co-ordinates in the fifth position.en_ZA
dc.identifier.apacitationSacht, C. (1985). <i>Studies with dithizone : the extraction of thallium (III)</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Chemistry. Retrieved from http://hdl.handle.net/11427/22161en_ZA
dc.identifier.chicagocitationSacht, Cheryl. <i>"Studies with dithizone : the extraction of thallium (III)."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Chemistry, 1985. http://hdl.handle.net/11427/22161en_ZA
dc.identifier.citationSacht, C. 1985. Studies with dithizone : the extraction of thallium (III). University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Sacht, Cheryl AB - Thallium(III) reacts with dithizone(I) in a complicated way through a number of intermediate products which depend on the relative proportions of reactants, the pH of the aqueous phase, the order of mixing of reactants, the time of phase equilibrium and the nature of the organic solvent used. The reaction between thallium(III) and dithizone is essentially oxidative in character. In the present work the complete reaction scheme is proposed: Thallium(III) reacts with dithizone to give a thallic-dithizonate complex, [TlIII(HDz)₃], which spontaneously and oxidatively disproportionates to the disulphide (III) and a thallium(I)-dithizonate complex, [Tl(HDz)]. The disulphide(III) decomposes by first-order heterolytic fission to give equimolar amounts of dithizone and the mesoionic compound (IV) . The Tl(HDz) complex undergoes reversion to give Tl+ in the aqueous phase and dithizone in the organic phase. In the presence of excess thallium(III) the regenerated dithizone is oxidized to the mesoionic compound (IV): the mesoionic compound (IV), partitions between the two phases and appears to react with excess thallium(III) to give possibly a mesoionic compound (IV)-thallium(III) complex and an unspecified oxidation product. The molecular structure of the 1 : 1 adduct formed between diphenylthallium( III) and dithizone has been shown by single crystal X-ray diffraction, to be a five co-ordinate diphenylthallium(III) complex: the dithizone acts as a bidentate chelating ligand co-ordinating through the nitrogen and sulphur atoms. Ethanol (solvent of recrystallisation) co-ordinates in the fifth position. DA - 1985 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1985 T1 - Studies with dithizone : the extraction of thallium (III) TI - Studies with dithizone : the extraction of thallium (III) UR - http://hdl.handle.net/11427/22161 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22161
dc.identifier.vancouvercitationSacht C. Studies with dithizone : the extraction of thallium (III). [Thesis]. University of Cape Town ,Faculty of Science ,Department of Chemistry, 1985 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/22161en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Chemistryen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherChemistryen_ZA
dc.titleStudies with dithizone : the extraction of thallium (III)en_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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