Thesis (MSc)--University of Stellenbosch, 2004 / ENGLISH ABSTRACT: A variety of computational techniques are used to calculate structural, thermodynamic and transport
properties of two specific Platinum Group Metal (PGM) complex systems. The first system consists of
a PGM complex ([PdCl4]2-; [PtCl4]2-; [PtCl6]2- or [RhCl6]3-) with sodium counter-ions in a water
solution at 30ºC and at a concentration of 0.106 mol/dm3. The second system under consideration is
that of a PGM complex ([PdCl4]2-; [PtCl4]2-; [PtCl6]2- or [RhCl6]3-) with sodium counter-ions in a water
solution in the presence of four poly (ethylene oxide) (PEO) chains at 30ºC and at a concentration of
0.013 mol/dm3. A conformational study of the two types of dihedral angles in a PEO chain (-C-O-C-Cand
-O-C-C-O-) is performed and the extreme flexibility of the polymer is confirmed. Dihedral angle
distributions of the two dihedral angles are calculated and explained in terms of the potential energy
surface obtained from the conformational study. The solvation geometries of the PGM complexes are
confirmed and the results are contrasted with those in the system where the polymer (PEO) is present.
It is concluded that the effect of the polymer on the structure and degree of solvation is negligible. The
free energy of solvation values of the PGM complexes are calculated to provide insight into their
structural characteristics such as solvation shell volume and geometry. The structural and
thermodynamic properties of the PGM complexes in solution are also used to explain the trends
observed in the calculated diffusion coefficients. Comments are made on the accuracy of the calculated
diffusion coefficients as well as the legitimacy of the mechanistic speculations which results from
them. Suggestions regarding possible future improvements to the computational methods are made. / AFRIKAANSE OPSOMMING: Verskeie berekenings tegnieke is aangewend om die strukturele, termodinamiese en verplasings
eienskappe van twee spesifieke Platinumgroep Metaal (PGM)-kompleks sisteme te bereken. Die eerste
sisteem bestaan uit die PGM-kompleks ([PdCl4]2-; [PtCl4]2-; [PtCl6]2- of [RhCl6]3-) met natrium teenione
in water by 30ºC en met ‘n konsentrasie van 0.106 mol/dm3. Die tweede sisteem bestaan uit die
PGM-kompleks ([PdCl4]2-; [PtCl4]2-; [PtCl6]2- of [RhCl6]3-) met natrium teen-ione in water in die
teenwoordigheid van vier poli-etileenoksied (PEO) kettings by 30ºC en met ‘n konsentrasie van 0.013
mol/dm3. ‘n Studie is gemaak van die konformasies van die twee soorte dihedrale-hoeke in ‘n PEOketting
(-C-O-C-C- en -O-C-C-O-) en die insense buigbaarheid van die polimeer is hiermee bevestig.
Die dihedrale-hoek-verspreidings van die twee tipes dihedrale hoeke is bereken en word verduidelik in
terme van die potensiёle energie kromvlakke soos bereken tydens die konformasie analiese. Die
geometrie van die solvasie van die PGM-komplekse is bereken en vergelyk met die sisteme waar die
polimeer (PEO) teenwoordig is. Hieruit word afgelei dat die effek van die polimeer op die struktuur en
graad van solvasie van die komplekse minimal is. Die vrye energie van solvasie van die PGMkomplekse
is bereken met die doel om insig in te win oor die stukturele eienskappe soos byvoorbeeld
die volume van die solvasie sfeer en die geometrie daarvan. Die strukturele en termodinamiese
eienskappe van die PGM-komplekse in oplossing word ook gebruik om die neigings in die berekende
diffusie koёffisiente te verduidelik. Opmerkings word gemaak aangaande die akkuraatheid van die
berekende diffusie koeffisiente asook die geldigheid van die meganistiese spekulasies wat daaruit
gemaak word. Voorstelle word ook gemaak rakende toekomsige verbeterings aan die reken tegnieke.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/16263 |
| Date | 04 1900 |
| Creators | Burger, M. R. (Marga Retha) |
| Contributors | Koch, K.R., Naidoo, K., University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | ix, [83] leaves : ill. |
| Rights | University of Stellenbosch |
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