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dc.contributor.advisorSwarts, J. C.
dc.contributor.authorFourie, Eleanor
dc.date.accessioned2018-07-23T08:35:50Z
dc.date.available2018-07-23T08:35:50Z
dc.date.issued2008-03
dc.identifier.urihttp://hdl.handle.net/11660/8908
dc.description.abstractEnglish: Metallocene-containing ligands, as well as their rhodium(I) complexes, were synthesized and their physical properties examined. Four known metallocene-containing β-diketones, FcCOCH2COR with R = CF3, Fc, Rc and Oc, were synthesized, as well as a range of metallocene-containing phosphine ligands, including the known PPh2Fc, and the new ligands PPh2Rc, PPh2Oc and the positively-charged (PPh2Cc+)(PF6 -). The new rhodium(I) dicarbonyl complexes [Rh(FcCOCHCOR)(CO)2], where R = CF3, Fc, Rc and Oc, were synthesized as starting materials for rhodium(I) phosphine complexes. Electron-rich phosphine complexes, containing metallocenyl-phosphines of the type [Rh(FcCOCHCOCF3)(CO)(PPh2Mc)], where Mc = Fc and Rc, as well as the known complex [Rh(FcCOCHCOCF3)(CO)(PPh3)], were synthesized. A series of electron-poor phosphine complexes containing pentafluorophenyl rings substituted on the phosphine ligand of the type [Rh(FcCOCHCOCF3)(CO){PPhn(C6F5)3-n}], with n = 0, 1 and 2, were also synthesized. Crystal structures of FcCOCH2COOc, PPh2Rc and [Rh(FcCOCHCOCF3)(CO)(PPh2Fc)] were solved. The oxidative addition (the first, rate determining step of the Monsanto process to form acetic acid) of methyl iodide to above mentioned rhodium(I) phosphine complexes were followed kinetically by UV, FT-IR, 1H NMR, 31P NMR and 19F NMR. Results showed that oxidative addition proceeded by up to three consecutive reaction steps, involving two Rh(III) alkyl and two Rh(III) acyl species. NMR results also showed the existence of at least two isomers of each Rh(III) alkyl and acyl species in the reaction mixture. Large variations in rate constant were observed. The rate of reaction for [Rh(FcCOCHCOCF3)(CO)(PPh2Rc)] {χR(Rc) =1.99, k1 = 0.015 dm3 mol-1 s-1} was found to be about double that of [Rh(FcCOCHCOCF3)(CO)(PPh2Fc)] {χR(Fc) = 1.87, k1 = 0.0075 dm3 mol-1 s-1}, with [Rh(FcCOCHCOCF3)(CO)(PPh3)] {χR(Ph) = 2.21, k1 = 0.006 dm3 mol-1 s-1} slightly slower. Rates of reaction for fluorinated compounds were dramatically slower, due to the highly electron-withdrawing pentafluorophenyl groups attached. [Rh(FcCOCHCOCF3)(CO){PPh2(C6F5)}] (k2 = 0.0003 dm3 mol-1 s-1) showed rates of reaction of up to 20x slower than that of [Rh(FcCOCHCOCF3)(CO)(PPh3)], with [Rh(FcCOCHCOCF3)(CO){PPh(C6F5)2}] (k2 = 0.000010 dm3 mol-1 s-1) showing rates of reaction 600x slower. [Rh(FcCOCHCOCF3)(CO){P(C6F5)3}] did not undergo oxidative addition at all. Acetylacetonato ligands substituted with a tetrathiafulvalene group in either the α- or the β-position of the β-diketone were complexed with rhodium(I) cyclooctadiene complexes to form [Rh(cod)(β-diketone)]. The substitution reaction of the TTF-containing β- diketonato ligand with 1,10-phenanthroline was investigated by stopped-flow methods due to the high rate of reaction for these compounds (k2 = 1 x 10 3 dm3 mol-1 s-1). A full electrochemical study was carried out on all synthesized complexes in CH2Cl2 / 0.1 mol dm-3 [NnBu4][B(C6F5)4] as solvent and supporting electrolyte. Where appropriate, spectro-electrochemical investigations were also performed. This study was also the first to develop techniques able to investigate slow kinetics electrochemically. The reaction used to develop these techniques was the isomerization from enol to keto form of the β- diketone RcCOCH2COFc. All newly synthesized compounds were tested for anti-tumor activity. It was found that the pentafluorophenyl group is a powerful anti-tumor fragment with significant synergism in [Rh(FcCOCHCOCF3)(CO){P(C6F5)3}]. Group electronegativity (χR) is the determining factor for cytotoxicity, in the absence of synergistic effects. An increase in group electronegativity leads to an increase in cytotoxicity. TTF-containing ligands also showed significant activity, but rhodium(I) complexes thereof had no effect.en_ZA
dc.description.abstractAfrikaans: Metalloseenbevattende ligande, sowel as hul rodium(I)-komplekse, is gesintetiseer en hul fisiese eienskappe bestudeer. Vier bekende metalloseenbevattende β-diketone, FcCOCH2COR met R = CF3, Fc, Rc en Oc, is gesintetiseer, sowel as die reeks PPh2Fc, PPh2Rc, PPh2Oc en die positief gelaaide (PPh2Cc+)(PF6 -) metalloseenbevattende fosfien ligande. Die voorheen onbekende rodium(I)-dikarbonielkomplekse [Rh(FcCOCHCOR) (CO)2], met R = CF3, Fc, Rc en Oc, is gesintetiseer as uitgangstof vir die sintese van rodium(I)-fosfienkomplekse. Nuwe elektronryk metalloseen-bevattende fosfienkomplekse, [Rh(FcCOCHCOCF3)(CO) (PPh2Mc)], met Mc = Fc en Rc, sowel as die bekende [Rh(FcCOCHCOCF3)(CO)(PPh3)], is gesintetiseer. ‘n Reeks elektronarm komplekse, wat pentafluoorfenielringe op die fosfienligande bevat, [Rh (FcCOCHCOCF3)(CO){PPhn(C6F5)3-n}] met n = 0, 1 en 2, is ook gesintetiseer. Die kristalstrukture van FcCOCH2COOc, PPh2Rc en [Rh(FcCOCHCOCF3)(CO)(PPh2Fc)] is opgelos. Die oksidatiewe addisiereaksie (die snelheidsbepalende eerste stap van die Monsantoproses vir die sintese van asynsuur) van metieljodied aan die bogenoemde rodium(I)- fosfienkomplekse is bestudeer met behulp van UV, FT-IR, 1H KMR, 31P KMR en 19F KMR. Resultate het gewys dat oksidatiewe addisie tot drie opeenvolgende stappe behels. Twee Rh(III)-alkiel- en twee Rh(III)-asielspesies is waargeneem. KMR-data het verder minstens twee isomere van elke Rh(I)-alkiel en -asielspesie geïdentifiseer. Groot verskille in die oksidatiewe addisiereaksiesnelhede is waargeneem. Die reaksietempo vir [Rh(FcCOCHCOCF3)(CO)(PPh2Rc)] {χR(Rc) = 1.99, k1 = 0.015 dm3 mol-1 s-1} is ongeveer dubbel die van [Rh(FcCOCHCOCF3)(CO)(PPh2Fc)] {χR(Fc) = 1.87, k1 = 0.0075 dm3 mol-1 s-1}, met [Rh(FcCOCHCOCF3)(CO)(PPh3)] {χR(Ph) = 2.21, k1 = 0.006 dm3 mol-1 s-1} se snelheid effens stadiger. Die reaksietempo’s vir fluoorbevattende komplekse was a.g.v. die sterk elektron-onttrekkende uitwerking van die pentafluoorfenielringe dramaties stadiger. Die tempo van [Rh(FcCOCHCOCF3) (CO){PPh2(C6F5)}] (k2 = 0.0003 dm3 mol-1 s-1) was ongeveer 20x stadiger as die van [Rh(FcCOCHCOCF3)(CO)(PPh3)], terwyl [Rh(FcCOCHCOCF3)(CO){PPh(C6F5)2}] (k2= 0.000010 dm3 mol-1 s-1) ongeveer 600x stadiger was. Die kompleks [Rh (FcCOCHCOCF3)(CO){P(C6F5)3}] het geen oksidatiewe addisie ondergaan nie. Asetielasetonatoligande wat in of die α- of die β-posisie gesubstitueer is met ‘n tetrathiafulvaleen-groep, is met rodium(I)-siklooktadieen gekomplekseer om [Rh(cod)(β- diketoon)] te gee. Die substitusiereaksies van die β-diketonato-ligande met 1,10- fenantrolien is bestudeer met behulp van stopvloeitegnologie, a.g.v. die hoë reaksietempos (k2 = 1 x 10 3 dm3 mol-1 s-1). ‘n Volledige elektrochemiese studie is uitgevoer op alle gesintetiseerde verbindings in CH2Cl2 / 0.1 mol dm-3 [NnBu4][B(C6F5)4] as oplosmiddel en hulpelektroliet. Waar van toepassing, is spektro-elektrochemiese studies ook uitgevoer. Hierdie studie was ook die eerste wat in staat was om tegnieke daar te stel waarmee kinetika van stadige reaksies elektrochemies bestudeer kan word. Die reaksie wat gekies is om die tegniek te ontwikkel was die isomerisasie van enol- na keto-vorms van die β-diketoon RcCOCH2COFc. Sitotoksiese toetse is op alle nuwe verbindings uitgevoer. Daar is gevind dat die pentafluoorfenielring ‘n kragtige antitumor-fragment is met beduidende sinergisme in [Rh(FcCOCHCOCF3)(CO){P(C6F5)3}]. Groepelektronegatiwiteite (χR) is die bepalende faktor vir die voorspelling van die sitotoksisiteit verbindinge. In die afwesigheid van sinergistiese effekte dui hoër groepelektronegatiwiteit op hoër sitotoksisiteit. Tatrathiafulvaleen-bevattende ligande het ook sitotoksiese aktiwiteit getoon, maar nie rodium(I)-komplekse daarvan nie.en_ZA
dc.description.sponsorshipNational Research Foundation (NRF)en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectRhodium(I)en_ZA
dc.subjectFerroceneen_ZA
dc.subjectPhosphineen_ZA
dc.subjectβ-diketoneen_ZA
dc.subjectOxidative additionen_ZA
dc.subjectSubstitution kineticsen_ZA
dc.subjectElectrochemistryen_ZA
dc.subjectGroup electronegativityen_ZA
dc.subjectPhosphine -- Synthesisen_ZA
dc.subjectPhosphorus compoundsen_ZA
dc.subjectOrganorhodium compoundsen_ZA
dc.subjectThesis (Ph.D. (Chemistry))--University of the Free State, 2008en_ZA
dc.titleA structural, electrochemical and kinetic investigation of fluorinated and metallocene-containing phosphines and their rhodium complexesen_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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