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English: Niobium and tantalum, chemical twins of the vanadium triad of the periodic table, are notoriously difficult to separate from one another and from their naturally occurring ores due to their near identical chemical properties. The significance of the separation of these two elements lies in the value and application of these elements in various fields of uses, especially noting the nuclear industry. Niobium with its high melting point, strength, resistance properties to chemical attack and the low neutron absorption cross-section (NAC) is ideally suited when alloyed with zirconium for cladding material in control rods of nuclear reactors to prevent leakage of nuclear reactive materials. Tantalum, on the other hand, has a much more limited application in the nuclear industry. It is mainly used in combination with carbon to form tantalum carbide which is used as a lining agent within the nuclear reactor (due to the corrosion resistance of tantalum). Due to that fact tantalum and niobium are always found together in mineral ores, tantalum is actually seen as a “pollutant” by nuclear chemists. This is why an efficient separation method is required because even the smallest impurity of one metal in the other would seriously degrade the ability of the metal to function in its particular role in a nuclear reactor. The principle aim of this study was to gain insight into the coordination and kinetic behaviour of Nb(V)- and Ta(V)-tropolonato and -acetylacetonato complexes. A detailed description of the synthesis of ten niobium(V)- and eight tantalum(V) complexes with the two ligand families (O,O’-donating) are reported and characterized by means of IR, UV/Vis and NMR (1H, 13C, 19F) spectroscopies. Furthermore, the solid state structural characterization, by means of single crystal XRay diffraction spectroscopy, yielded eleven of these synthesized compounds which were described in detail in three separate sections. The original focus of this crystallographic investiga, Afrikaans: Niobium en tantaal, chemiese tweeling van die vanadium drietal van die periodieke tabel, is berug daarvoor dat skeiding tussen die twee en vanuit hulle natuurlike ertse besonder moeilik is danksy hulle amper identiese chemiese eienskappe. Die belangrikheid van die skeiding van hierdie twee elemente lê in die waarde en toepassing van hierdie elemente in verskillende velde van gebruik, veral in die kern bedryf. Niobium, met sy hoë smeltpunt, sterkte, weerstandseienskappe teen chemiese aanval en die lae neutron absorpsie deursnee (NAD) is ideaal vir gebruik as bekleding materiaal in beheerstawe van kernreaktore om lekkasie van kernreaktiewe materiaal te voorkom wanneer dit met sirkonium gelegeer is. Daarenteen het tantaal ʼn baie meer beperkte toepassing in die kernnywerheid. Dit word grotendeels in kombinasie met koolstof gebruik om tantaalkarbied te vorm wat as voeringsagent binne die kernreaktor gebruik word weens die roesweerstand van tantaal. Aangesien tantaal en niobium altyd saam in mineraalerts gevind word, word tantaal as “besoedeling” beskou deur kernchemici. ʼn Effektiewe skeidingsmetode word dus vereis aangesien selfs die kleinste onsuiwerheid van een metaal in die ander die vermoë van die metaal om sy funksie in die kernreaktor te verrig ernstig sal belemmer. Die hoofdoel van hierdie studie was om insig in te win rakende die koördinering en kinetiese gedrag van Nb(V)- en Ta(V)-tropolonato en -asetielasetonato komplekse. ʼn Breedvoerige beskrywing van die sintese van tien niobium(V) en agt tantaal(V) komplekse met die twee ligandfamilies (O,O’-skenkend) word gerapporteer; die komplekse is gekarakteriseer deur middel van IR, UV/Vis en KMR (1H, 13C, 19F) spektroskopie. Daarbenewens het die vaste toestand struktuurkarakterisering deur middel van enkelkristal X-straal diffraksie elf van hierdie vervaardigde verbindings opgelewer en dit word breedvoerig in drie afdelings bespreek. Die oorspronklike fokus van hierdie kristallografiese ondersoek was die ka, Advanced Metals Initiative (AMI); Department of Science and Technology (DST) of South Africa; New Metals Development Network (NMDN); South African Nuclear Energy Corporation Limited (Necsa)

English: Both technetium and rhenium have been studied extensively over the years, due to their ability to coordinate with mono- and bidentate ligands to form metal(I) tricarbonyl complexes, fac-[M(CO)3(X)(L,L’-Bid)] (M = Tc(I) and Re(I), L,L’-bid = bidentate ligand and X = MeOH, H2O or Br). The interest in these complexes is based on the diagnostic properties of technetium and therapeutic properties of rhenium in the study of radiopharmaceuticals. These complexes possess characteristics that can be utilized for the application in nuclear medicine. The aim of this study was based on the study of the chemistry of technetium and rhenium to gain more information about their ability to coordinate with potential ligands such as Schiff base ligands. From this, a Schiff base ligand such as 5-methyl-(2- cyclohexyliminomethyl)phenol – 5Me-Sal-Cyhex was synthesized and characterized. This was successfully coordinated to fac-[M(CO)3]+ core to form metal(I) tricarbonyl complexes. The synthesis and characterization of the N,O-bidentate ligand or Schiff base ligand and all metal complexes are reported in Chapter 3. All rhenium products obtained were characterized by UV/Vis, NMR (1H and 13C) and IR. The rhenium complexes, fac-[Re(CO)3(X)(N,O-Bid)], were synthesized with variety of monodentate ligands (X = MeOH, imidazole, pyridine and pyrazole) coordinated on the sixth position. Three crystal structures of 5-methyl-(2-cyclohexyliminomethyl)phenol – 5Me-Sal- Cyhex, fac-[Re(CO)3(MeOH)(5Me-Sal-Cyhex)] and fac-[Re(CO)3(Imid)(5Me-Sal-Cyhex)] were obtained from the characterization performed by X-ray diffraction. These complexes crystallised in the orthorhombic and monoclinic crystal systems in the respective space groups of P212121, C2/c and P21/n. Technetium(I)-99 tricarbonyl complexes, fac-[99Tc(CO)3(MeOH)(5Me-Sal-Cyhex)] and fac- [99Tc(CO)3(MeCN)(5Me-Sal-Cyhex)] were synthesized and characterized by HPLC to determine the reaction completion and chemical similarity between rhenium an, Afrikaans: Beide tegnesium en renium is breedvoerig oor die jare bestudeer as gevolg van hulle vermoë om met mono- en bidentate ligande te koördineer om metaal(I) trikarbonielkomplekse, fac- [M(CO)3(X)(L,L’-Bid)] (M = Tc(I) en Re(I), L,L’-bid = bidentate ligand en X = MeOH, H2O of Br-), te vorm. Die belangstelling in hierdie komplekse is gebaseer op die diagnostiese eienskappe van tegnesium en terapeutiese eienskappe van renium in die bestudering van kerngenees middels. Hierdie komplekse beskik oor eienskappe wat gebruik kan word in die toepassing van kerngeneeskunde. Die doel van hierdie ondersoek is gegrond op die bestudering van die chemie van tegnesium en renium ten einde meer inligting in te win oor hulle vermoë om met potensiële ligande soos Schiff-basis te koördineer. Vir hierdie projek is ʼn Schiff-basis ligand, 5-metiel-(2- sikloheksieliminometiel)fenol – 5Me-Sal-Cyhex (5Me-Sal-Siheks) – vervaardig en gekarakteriseer. Dit is suksesvol aan die fac-[M(CO)3]+ entiteit gekoördineer om metaal(I) trikarboniel komplekse te vorm. Die sintese en karakterisering van die N,O-bidentate ligand, of Schiff-basis, asook alle metaalkomplekse word in die studie gerappoteer. Alle gesintetiseerde renium produkte is met behulp van UV/Vis, KMR (1H en 13C) en IR spektroskopie gekarakteriseer. Die reniumkomplekse, fac-[Re(CO)3(X)(N,O-Bid)], is gesintetiseer met ʼn verskeidenheid monodentate ligande (X = MeOH, imidasool, piridien en pirasool) in die sesde posisie gekoördineer. Drie kristalstrukture van 5-metiel-(2-sikloheksieliminometiel)fenol – 5Me-Sal- Cyhex, fas-[Re(CO)3(MeOH)(5Me-Sal-Cyhex)] en fas-[Re(CO)3(Imid)(5Me-Sal-Cyhex)] is gekaratireseer deur middel van X-straal diffraksie. Hierdie komplekse het in die ortorombiese en monokliniese kristalstelsels gekristalliseer, in die ruimtegroepe P212121, C2/c en P21/n, onderskeidelik. Tegnesium(I)-99 trikarboniel komplekse, fas-[99Tc(CO)3(MeOH)(5Me-Sal-Cyhex)] en fas- [99Tc(CO)3(MeCN)(5Me-Sal-Cyhex)] is gesintetiseer en gekarakterise

English: Hydroformylation of alkenes (olefins) is one of the world’s leading aldehyde producing process. The resulting aldehydes can easily be converted to secondary products such as alcohols for production of plasticizers and detergents. Recent studies are directed towards the production of highly selective catalysts as linear aldehydes are the most desired products. A number of phosphine ligands have been investigated regarding this process, showing that fine tuning of the ligands electronic and steric properties significantly affects the activity and selectivity of a catalyst. A range of diphosphinoamine (PNP) ligands with various substituents on the nitrogen atom were synthesized and characterized, namely (1) N,N-Bis(diphenylphosphino)-p-toluidine [CH3-Ph-PNP],(2) N,N-Bis(diphenylphosphino)-4-chloroaniline [Cl-Ph-PNP], (3) N,N-Bis(diphenylphosphino)-4-fluoroaniline [F-Ph-PNP], (4) N,N-Bis(di-p-tolylphosphino)-p-toluidine [5-p-tolyl-PNP], (5) N,N-Bis(di-p-tolylphosphino)-o-toluidine [4-p-tolyl-o-tol], (6) N,N-Bis(di-p-tolylphosphino)cyclohexylamine [Chzyl-4-p-tolyl] and (7) N,N-Bis(di-p-tolylphosphino)cyclobutylamine [Cbutyl-4-p-tolyl] (see Figure 1). These ligands were systematically synthesized to induce different steric and electronic properties on the nitrogen atom. All the ligands were coordinated to Pt(II) and Pd(II) metals to serve as models for Rh(I) pre-catalysts systems to be used in hydroformylation of 1-octene. Metal complexes which produced crystals suitable for X-ray data analysis were (A) Dichloro-[N,N-Bis(di-p-tolylphosphino)-p-toluidine-k2P,P’]platinum(II) [Pt(5-p-tolyl-PNP)Cl2], (B) Dichloro-[N,N-Bis(di-p-tolylphosphino)-o-toluidine-k2P,P’]platinum(II) [Pt(4-p-tolyl-o-tol)Cl2], (C) Dichloro-[N,N-Bis(diphenylphosphino)-4-chloroaniline-k2P,P’]palladium(II) [Pd(Cl-Ph-PNP)Cl2], (D) Dichloro-[N,N-Bis(diphenylphosphino)-p-toluidine-k2P,P’]palladium(II) [Pd(5-p-tolyl-PNP)Cl2], (E) Dichloro-[N,N-Bis(di-p-tolylphosphino)cyclobutylamine-k2P,P’]platinum(II, Afrikaans: Hidroformilering van alkene (olefiene) is een van die wêreld se belangrikste aldehied-vervaardigingsprosesse. Die gevolglike aldehiede kan maklik na sekondêre produkte soos alkohole vir die vervaardiging van plastiseerders en skoonmaakmiddels omgeskakel word. Onlangse studies is gerig op die vervaardiging van hoogs selektiewe kataliste aangesien liniêre aldehiede die mees gesogde produkte is. `n Aantal fosfienligande is ondersoek rakende hierdie proses, en die studies het aangedui dat verfyning van die elektroniese en steriese eienskappe van ligande `n beduidende uitwerking op die aktiwiteit en selektiwiteit van `n katalis het. `n Reeks difosfinoamien (PNP) ligande met verskeie substituente op die stikstofatoom is vervaardig en gekarakteriseer, naamlik (1) N,N-Bis(difenielfosfino)-p-toluïdien [CH3-Ph-PNP],(2) N,N-Bis(difenielfosfino)-4-chlooranilien [Cl-Ph-PNP], (3) N,N-Bis(difenielfosfino)-4-fluooranilien [F-Ph-PNP], (4) N,N-Bis(di-p-tolielfosfino)-p-toluïdien [5-p-toliel-PNP], (5) N,N-Bis(di-p-tolielfosfino)-o-toluïdien [4-p-toliel-o-tol], (6) N,N-Bis(di-p-tolielfosfino)sikloheksiel-amien [Chzyl-4-p-toliel] en (7) N,N-Bis(di-p-tolielfosfino)siklobutielamien [Cbutiel-4-p-toliel] (sien Figuur 1). Hierdie ligande is sistematies vervaardig om verskillende steriese en elektroniese eienskappe op die stikstofatoom te induseer. Alle ligande is aan Pt(II) en Pd(II) metale gekoördineer om as modelle te dien in Rh(I) pre-katalitiese stelsels vir gebruik in hidroformilering van 1-okteen. Metaalkomplekse wat geskikte kristalle vir X-straaldiffraksie gevorm het is (A) Dichloor-[N,N-Bis(di-p-tolielfosfino)-p-toluïdien-k2P,P’]platinum(II) [Pt(5-toliel-PNP)Cl2], (B) Dichloor-[N,N-Bis(di-p-tolielfosfino)-o-toluïdien-k2P,P’]platinum(II) [Pt(4-toliel-tol)Cl2], (C) Dichloor-[N,N-Bis(difenielfosfino)-4-chlooranilien-k2P,P’]palladium(II) [Pd(Cl-Ph-PNP)Cl2], (D) Dichloor-[N,N-Bis(difenielfosfino)-p-toluïdien-k2P,P’]palladium(II) [Pd(5-p-toliel-PNP)Cl2], (E) Dichloor-[N,N-Bis(d, University of the Free State, SASOL

English: Zirconium and hafnium, the chemical twins in the titanium triad of the periodic table, are chemically very similar, but exhibit a significant difference in their nuclear properties, and also most noteworthy, their application in industry. Zirconium, with its very low affinity for thermal neutrons (radioactive energy), high thermal stability and exceptional anti-corrosive properties, is widely used as cladding material for nuclear reactor fuel rods. Hafnium, on the other hand, with its very high affinity for thermal neutrons is most often employed as control rods, used for regulating the rate of fission in nuclear reactors. For this application alone, it is apparent why the separation of these metals to their chemically pure state, is so important. Even the smallest impurity of one metal in the other would seriously degrade the ability of the metal to function in its particular role in a nuclear reactor. In this study, the solid state and solution behaviour of zirconium(IV) coordination compounds, containing N- and O-donating multidentate ligands, is investigated. A detailed description of the synthesis of 25 zirconium(IV) complexes with three ligand families – O,O’-donating, oxines and pyridines – are reported and characterised by means of IR, UV/Vis and NMR (1H & 13C) spectroscopies. Furthermore, the solid state structural characterisation, by means of single crystal X-Ray Diffraction spectroscopy, of eight of these synthesised complexes is described in detail. Six novel oxine-type complexes – [Zr(diClOx)4]∙2DMF, [Zr(5-ClOx)4]∙2DMF, [ZrCl(CliOx)2(DMF)2O]2∙DMF, [Zr(diMeOx)4] ∙2DMF, [Zr(5-NO2Ox)4] and [Zr(Pic)4]∙2H2O – are discussed and compared with regard to the intimate geometric environment around the zirconium(IV) metal centre [where 5,7-Dichloro-8-hydroxyquinoline (diClOxH), 5-Chloro-8-hydroxyquinoline (5-ClOxH), 5-Chloro-7-iodo-8-hydroxyquinoline (CliOxH), 5,7-Dimethyl-8-hydroxyquinoline (diMeOxH), 5-Nitro-8-hydroxyquinoline (5-NO2OxH), 2-Picolinic ac, Afrikaans: Sirkonium en hafnium, die chemiese tweeling in die titaangroep van die periodieke tabel, is chemies baie soortgelyk, maar toon 'n betekenisvolle verskil in hul kerneienskappe, en veral tov hul toepassing in die industrie. Sirkonium, met sy baie lae affiniteit vir termiese neutrone (radio-aktiewe energie), hoë termiese stabiliteit en uitsonderlike antikorrosie-eienskappe, word algemeen gebruik as dekmateriaal vir kernreaktorbrandstof. Hafnium daarteenoor, met sy hoë affiniteit vir termiese neutrone, word dikwels gebruik as beheerstawe in die kernbrandstof, wat gebruik word vir die temporegulering van die kernreaksie binne-in die reaktore. Deur bloot hierdie toepassing in aanmerking te neem blyk dit duidelik waarom die effektiewe skeiding van hierdie metale in hul chemiese suiwer toestand krities belangrik is. Selfs klein onsuiwerheid van een metaal in die ander kan die vermoë van die ander een betekenisvol negatief in 'n kernreaktor beïnvloed. In hierdie studie is die vastetoestand- en oplossinggedrag van sirkonium(IV) koördinasieverbindings, met N- en O-elektrondonor multidentaatligande ondersoek. 'n Volledige beskrywing van die sintese van 25 sirkonium(IV)komplekse met drie reekse ligandgroepe – O,O’-donoratome (asetielasetonaattipe), sowel as beide oksien en piridien (d.w.s. O- en N-donoratoomligande) – word gerapporteer en is gekarakteriseer deur middel van IR, UV / Vis en KMR (1H en 13C) spektroskopie. Die vastetoestandstrukture van agt van hierdie gesintetiseerde komplekse, soos bepaal deur middel van enkelkristal X-straaldiffraksie, word in detail beskryf. Ses nuwe oksien-tipe komplekse, nl. [Zr(diClOx)4]∙2DMF, [Zr(5-ClOx)4]∙2DMF, [ZrCl(CliOx)2(DMF)2O]2∙DMF, [Zr(diMeOx)4]∙2DMF, [Zr(5-NO2Ox)4] en [Zr(pic)4]∙2H2O, word bespreek en die koördinasiepolihedra rondom die Zr(IV) vergelyk [met 5,7-Dichloro-8-hidroksiekinolien (diClOxH), 5-Chloro-8-hidroksiekinolien (5-ClOxH), 5-Chloro-7-iodo-8-hidroksiekinolien (CliOxH), 5,7-Dimetiel-8-hidroksiekinolien (diM, Advanced Metals Initiative (AMI)

Manganese has largely been used as a catalyst in epoxidation of olefins and the selective oxidation of unactivated C-H bonds in alkanes. Another major use of manganese is in water oxidizing catalysis, where manganese compounds are used in the production of hydrogen by water splitting. By looking at the manganese triad, a lot of radiopharmaceutical studies have been performed with Technetium. 99mTc is the radionuclide of choice since it has the ideal properties necessary for potential radiopharmaceuticals. Rhenium has been used as model for technetium radiopharmaceuticals and 188Re and 186Re have proved their use in bone metastases. Manganese has not been used in radiopharmaceuticals as it is somewhat toxic to the body. Some studies have been performed on tumor suppression using MnSOD, a mitochondrial enzyme. Very little work has been done on manganese coordination chemistry especially in terms of tricarbonyl aqua complexes. So far about 5 manganese tricarbonyl aqua complexes have been reported on the CSD. In this study, a comparison of manganese (I) and rhenium (I) tricarbonyl complexes is made. Rhenium (I) tricarbonyl aqua complexes have been synthesized by Kemp and Schutte et al. using N,N’-, N,O- and O,O’- bidentate ligands. The chosen N;N’- bidentate ligands are 2,2’-bipyridyl (Bipy) and 1,10-phenanthroline (Phen), N,Obidentate ligands are quinoline-2,4-dicarboxylic acid (2,4-Quin) and picolinic acid (Pico) and finally the O,O’-bidentate ligands chosen were 3-hydroxyflvone (Flav) and tropolone (Trop). In this study, the same N,N’- and N,O-bidentate ligand systems were used as well as 3-hydroxyflavone as O,O’-bidentate ligand in order to successfully compare these two metal cores. The synthesis of all the complexes has been reported in Chapter 3 and these were characterized by UV/vis, 13C NMR, 1H NMR and IR. Only two of the complexes were characterized by X-ray diffraction; fac-[Mn(CO)3(Bipy)(H2O)][CF3SO3] and fac- [Mn(CO)3(Phen)(H2O)][CF3SO3]. These monoclinic c

English: This research focuses on the development of new teatradentate carboxamide ligands and their coordination to gallium(III) and gold(III). The solid state characteristics and reactivity studies in solution of these model compounds would give more insight into the behaviour of radiopharmaceuticals for cancer treatment. The crystallographic characterization of two carboxamide ligands, di-Mebpb and bpb and two metal complexes, [Ga(bpb)(H2O)2]NO3·CH3OH and [Au(bpb)]Cl, is fully discussed and compared to literature in Chapter 5. The ligand, di-Mebpb crystallizes in a non-centrosymmetric, monoclinic Cc space group, with four molecules per unit cell. The ligand, bpb crystallizes in a centrosymmetric monoclinic P21/c space group, with four molecules in the unit cell. The dihedral angles between the central phenyl ring and the two picoline rings for the di-Mebpb ligand, is calculated as 57.06(5) ° and 22.05(8) °, respectively and the dihedral angle between the central phenyl ring and the two picoline rings of the bpb ligand are calculated as 57.82(4) ° and 17.96(7) °, respectively. [Ga(bpb)(H2O)2]NO3·CH3OH crystallizes in a centrosymmetric, orthorhombic Pbca space group, with four molecules per unit cell while the [Au(bpb)]Cl, complex crystallizes in a centrosymmetric, triclinic Pī space group, with two molecules per unit cell. The octahedron around the gallium(III) ion is somewhat distorted as indicated by the large bite angle of N1-Ga-N4 (115.03(1) °) and the small bite angle of O4-Ga-O3 (161.62(1) °). The gold(III) complex crystallizes in a distorted square planar formation with the gold(III) deviating 0.0518(3) Å from the plane formed by the four coordinating nitrogen atoms (N1-N2-N3-N4) and the bond angles of N-Au-N range from 81.8(2) ° to 111.9(2). °. A kinetic investigation was conducted to follow the rate at which methanol is substituted from a trans-[Ga(bpb)(CH3OH)2]+ complex with 4-methylpyridine as entering ligand. The proposed substitution mechanism is post, Afrikaans: Hierdie navorsing fokus op die ontwikkeling van nuwe tetradentate karboksamied ligande en hulle koördinasie aan gallium(III) en goud(III). Die vaste toestand eienskappe en reaktiwiteit studies in oplossing van hierdie model komplekse bied `n dieper insig in die gedrag van radiofarmaseutika vir kanker behandeling. Die kristallografiese eienskappe van twee karboksamied ligande, di-Mebpb en bpb, en twee metal komplekse, [Ga(bpb)(H2O)2]NO3·CH3OH en [Au(bpb)]Cl, word volledig bespreek en met literatuur vergelyk in Hoofstuk 5. Die ligand di-Mebpb kristalliseer in die nie-sentrosimmetriese, monokliniese Cc ruimtegroep, met vier molecule per eenheidsel. Die ligand bpb kristalliseer in die sentrosimmetriese, monokliniese P21/c ruimtegroep, met vier molecule per eenheidsel. Die dihedriese hoeke tussen die sentrale feniel ring en die twee pikolien ringe in die di-Mebpb ligand is bereken as 57.06(5) ° en 22.05(8) °, onderskeidelik, en dihedriese hoeke tussen die sentrale feniel ring en die twee pikolien ringe in die bpb ligand is bereken as 57.82(4) ° en 17.96(7) °, onderskeidelik. [Ga(bpb)(H2O)2]NO3·CH3OH kristalliseer in die sentrosimmetriese, ortorombiese Pbca ruimtegroep, met vier molecule per eenheidsel, terwyl die [Au(bpb)]Cl kompleks in die sentrosimmetriese, Pī ruimtegroep kristalliseer, met twee molecules per eenheidsel. Die octa hedron rondom die gallium(III) ioon is effens vervorm, soos aangedui deur die groot bythoek van N1-Ga-N4 (115.03(1) °) en die klein bythoek van O4-Ga-O3 (161.62(1) °. Die goud(III) kompleks kristalliseer in `n vervormde vierkantig planêre vormasie met `n uitwyking van 0.0518(3) Å vir die goud(III) atom uit die vlak gevorm deur die vierkoördinerende stikstof atome (N1-N2-N3-N4) en bindingshoeke van N-Au-N wat wissel van 81.8(2) ° tot 111.9(2) °. `n Kinetiese ondersoek is uitgevoer om die tempo waarteen methanol uit trans-[Ga(bpb)(CH3OH)2]+ vervang word deur 4-metielpiridien vas te stel. Die voorgestelde uitruilings meganisme behels t, University of the Free State, NTeMBI, NRF/THRIP, Sasol

English: Hydroformylation for the production of aldehydes from alkenes, is a large and important homogeneously catalyzed industrial process. Most of these resulting aldehydes are hydrogenated to alcohols, having applications in plasticizer alcohols, detergents, wood preservatives and surfactants. Numerous phosphine ligands have been applied in these catalytic reactions signifying that changes in the ligand environment induce different steric and electronic properties into the catalyst system allowing to "tune" catalyst behaviour towards higher activity and selectivity. A series of diphosphinoamine (PNP) ligands with various substituents on the N-atom, inducing different steric properties were synthesized and characterized (Scheme I). Single crystal X-ray crystallographic studies of the PNP ligands revealed that the P-N-P bond angle decreases as the steric bulk of the alkyl moiety increases. See scheme in PDF full text. The synthesis and coordination of the PNP-ligands to Pt(ID and Pd(ID served as models to quantify different effects which could then be rationalized for the Rh(I) and Ir(I) pre-catalysts systems for use in olefin hydroformylation. The reason for using Pt(ID and Pd(ID was therefore primarily to gain information on the coordination mode of these ligands, rather than the notoriously difficult to isolate and unstable Rh and Ir complexes. A total of three free PNP-ligands, four [Pt(PNP-alkyl)2] and one [Pd(PNP-alkyl)2] solid state crystal structures were solved, which provided excellent structural fundamentals from which the catalysis could be pursued. The study was also supplemented with theoretical chemistry. The comparison between the optimized structure and the crystal data revealed small differences, illustrating that predictions can be made in terms of ligand design in particular when solid state data is hard to obtain. The calculated structures indicated that the phenyl ring arrangement is affected by the steric bulk of the nitrogen-coordinated alky, Afrikaans: Hidroformilering vir die produksie van aldehiede vanaf alkene is 'n groot en belangrike homogene katalitiese nywerheidsproses. Die meeste van die gevolglike aldehiede word gehidrogeneer na alkohole en word gebruik as plastiseerder alkohole, skoonmaakmiddels, hout preserveermiddels en benatters. Veelvuldige fosfienligande is al gebruik in hierdie katalitiese reaksies, wat aandui dat veranderinge in die ligandomgewing verskillende steriese en elektroniese eienskappe in die katalitiese stelsel veroorsaak en dus hoer aktiwiteit en selektiwiteit tot gevolg het. 'n Reeks difosfienamien (PNP) ligande met verskeie substituente op die N-atoom, wat verskillende steriese eienskappe veroorsaak, is gesintetiseer en gekarakteriseer (Skema I). Enkelkristal X-straal kristallografiese studies van die PNP ligande het onthul dat die P-N-P bindingshoek afneem wanneer die steriese massa van die alkielgroep toeneem. Sien skema in PDF volteks. Die sintese en koordinasie van die PNP-ligande aan Pt(II) en Pd(II)

English: Rhenium is the third row congener and 5d analogue of technetium. Technetium is the most widely used radionuclide in diagnostic imaging, thus it would be advantageous to explore the use of rhenium as a possible therapeutic radiopharmaceutical. The advantage of using rhenium instead, is that it is non-radioactive in its natural form, possessing similar properties as technetium. Their (rhenium and technetium) chemical behaviour is so similar that it is almost impossible for biological systems to differentiate between them. These similarities include size, shape, lipophillicity, dipole moment, charge and ionic mobility, thus forming complexes of the same geometry. The main attraction in the use of rhenium as a potential radiopharmaceutical agent is the fac-[Re(CO)3]+ moiety. Only a few crystal structures of the form, fac-[Re(O-O’)(CO)3X], (O-O’ = bidentate ligands and X being halides, monodentate ligands etc.) has been published. In 2012 only ten crystal structures containing O,O’- donor bidentate ligands have been introduced. Substitution kinetic studies using rhenium tricarbonyl complexes is still an under explored field. The principle aim in this study, was to synthesise complexes of the form, fac-[M(L,L’)3(CO)3X] (M = Re, Tc; L,L’ = O,O’- and N,O-donor bidentate ligands; X = Br-, Py, H2O). These bidentate ligands include compounds that are biologically active. In synthesising these complexes, two new rhenium(I) crystal structures, containing O,O’-donor bidentate ligands have been introduced. The bidentate ligand systems, used in this study was O,O’ -donor ligand systems, acetylacetone (Acac), trifluoroacetylacetone (TFA), hexafluoroacetylacetone (HFA) and N,O-donor ligands, ephedrine (Eph) and 8-hydroxyl-quinoline (8-Quin). The following three 99mTc complexes were synthesised, fac-[99mTc(Acac)(CO)3(H2O)], fac-[99mTc(TFA)(CO)3(H2O)] and fac-[99mTc(HFA)(CO)3(H2O)] and their formation was established, using reverse phase thin layer chromatography (TLC). Their, Afrikaans: Tegnesium is die radionuklied wat die meeste gebruik word in diagnostiese beelding. Tenium kom voor in dieselfde groep (Groep VII) as tegnesium en is sy 5d analoog, daarom sal dit voordelig wees om die gebruik van renium as 'n moontlike terapeutiese readiofarmaseutiesemiddel te bestudeer. Renium en tegnesium het dieselfde eienskappe, en omdat renium nie radioaktief is in sy natuurlike vorm nie, sal dit beter wees om dit te gebruik in plaas van tegnesium. Hulle chemiese gedrag is soortgelyk en dit maak dit amper onmoontlik vir biologiese sisteme om tussen die twee te kan onderskei. Hierdie ooreenkomste sluit hulle grootte, lipofilisiteit, dipool moment, lading en ioniese mobiliteit in, daarom vorm hulle ook komplekse van dieselfde geometrie. Die grootste aantrekking vir die gebruik van renium as 'n moontlike radiofarmaseutiese agent, is die fac-[Re(CO)3]+ moïeteit. Min kristal strukture met die vorm fac-[Re(O-O’)(CO)3X], (O-O’ = bidentate ligande en X halide, monodentate ligande ens.) is gepubliseer. In 2012 is net tien kristal strukture, wat O-O’ -bidentate ligande bevat, alreeds gepubliseer. Baie min werk is gedoen op die renium trikarboniel komplekse, met betrekking tot substitusie kinetika. Die doel van hierdie studie was om komplekse met die volgende vorm, fac-[M(L,L’)3(CO)3X] (M = Re, Tc; L,L’ = O,O’- en N,O-skenkede bidentate ligande; X = Br-, Py, H2O), te sintetiseer. Die bidentate ligande wat gebruik is, sluit biologiese aktiewe verbindings in. Die O,O’-skenkings bidentate ligand sisteme wat gebruik is, is asetielasetoon (Acac), trifluooroasetielasetoon (TFA) en heksafluooroasetielasetoon (HFA), terwyl efedrien (Eph) en 8-hidroksiekinolien (8-Quin) as N,O-skenkende ligande gebruik is. Drie 99mTc kompleke word ook gesintetiseer, insluitende fac-[99mTc(Acac)(CO)3(H2O)], fac-[99mTc(TFA)(CO)3(H2O)] en fac-[99mTc(HFA)(CO)3(H2O)]. Die vorming van hierdie produkte is deur middel van die omgekeerde fase 'TLC' metode bevestig. Die Rf waardes vermeerder as, Ntembi, National Research Foundation (NRF), University of the Free State

English: The aim of the study was to synthesize several novel Co(II)-, Co(III)- and Cr(III) complexes using an O,O-bidentate ligand, methylene diphosphonate, and to characterize these complexes by various means. Characterization of the complexes was done by elemental analysis, infrared spectroscopy, nuclear magnetic resonance spectroscopy (NMR), single X-ray crystallography and X-ray photoelectron spectroscopy (XPS). The methylene diphosphonate ligand was selected as it is a ligand employed in a bone imaging agent in the radiopharmaceutical sector. Little is known about the structure and coordination chemistry of metal complexes with methylene diphosphonate. Single crystal X-ray crystallographic structure determinations of six new structures were completed: (1) Pyridinium diaquabis(methylenediphosphonato)chromate(III) tetrahydrate (2) Potassium diaquabis(methylenediphosphonato)cobaltate(III) (3) Potassium diaquadihydroxy(methylenediphosphonato)cobaltate(III) (4) Diammonium diaquabis(methylenediphosphonato)cobaltate(II) (5) Disodium diaquabis(methylenediphosphonato)cobaltate(II) dihydrate (6) Dicesium diaquabis(methylenediphosphonato)cobaltate(II) Each complex has a slightly distorted octahedral geometry. The cobalt or chromium ion in each complex is coordinated to four oxygen atoms derived from two methylene diphosphonate ligands, except for K[Co(CH4O6P2)(OH)2(H2O)2] which has two oxygen atoms from one methylene diphosphonate ligand coordinated to it. In addition each complex has two aqueous molecules which are coordinated to the metal center. Two phosphonate oxygen atoms from the ligand, methylene diphosphonate define the equatorial plane, whereas the water molecules reside in the axial positions. See Table in full text PDF. These complexes correlate with other similar complexes but the occurrence of similar structures in literature is very limited, showing that this field is open to further study. We were unable to perform any meaningful studies on these complexes, Afrikaans: Die doel van die studie was die sintese van verskeie oorspronklike Co(II)-, Co(III)- en Cr(III) komplekse met die gebruik van `n O,O-bidentate ligand, metileen difosfonaat, en die karakterisering van hierdie komplekse deur verskillende tegnieke. Karakterisering van die komplekse is gedoen deur elementele analise, infrarooi spektroskopie, kernmagnetieseresonans (KMR) spektroskopie, enkelkristal X-straal kristallografie asook X-straal foto-elektron spektroskopie (XPS). Die metileen difosfonaat ligand is gekies aangesien dit gebruik word as `n ligand in `n been beeldingsagent in die radiofarmaseutiese bedryf. Die struktuur en koördinasiechemie van metaalkomplekse met metileen difosfonaat is redelik onbekend. Enkelkristal X-straal kristallografiese struktuurbepalings van ses nuwe strukture is voltooi: (1) Piridinium diakwabis(metileendifosfonato)chromaat(III) tetrahidrate (2) Kalium diakwabis(metileendifosfonato)kobaltaat(III) (3) Kalium diakwadihidroksie(metileendifosfonato)kobaltaat(III) (4) Diammonium diakwabis(metileendifosfonato)kobaltaat(II) (5) Dinatrium diakwabis(metileendifosfonato)kobaltaat(II) dihidrate (6) Disesium diakwabis(metileendifosfonato)kobaltaat(II) Elke kompleks het `n effens verwronge oktahedriese geometrie. Die kobalt of chroom ioon in elke kompleks is aan vier suurstofatome gekoördineer; afkomstig van twee metileen difosfonaat ligande, behalwe vir K[Co(CH4O6P2)(OH)2(H2O)2] wat twee suurstofatome van een metileen difosfonaat ligand daaraan gekoördineer het. Benewens die bogenoemde het elke kompleks twee akwa molekule aan die metaalsenter gekoördineer. Twee fosfonaat suurstofatome van die ligand, metileen difosfonaat definieer die ekwatoriale vlak, terwyl water molekule die aksiale posisies betrek. Sien Tabel in volteks PDF. Hierdie komplekse stem ooreen met ander soortgelyke komplekse maar die voorkoms van soortgelyke strukture in die literatuur is baie beperk, wat aantoon dat hierdie veld oop is vir verdere studiemoontlikhede. Geen be, University of the Free State, National Research Foundation (NRF)

English: Rhenium(I) and technetium(1) tricarbonyl complexes hold significant potential as model radiopharmaceuticals which could be utilized as therapeutic and imaging agents. 99mTechnetium in particular, is one radionuclide which is used in more than 80% of radiopharmaceuticals as a diagnostic agent. The biodistribution of a potential radiopharmaceutical can in principle be manipulated by the coordination of a biologically active molecule to the radionuclide. The principle aim of this study was to gain further insight into the chemistry, coordination and kinetic behaviour of fac-[M(CO)3+ (M = Tc, Re) complexes. With this idea in mind, a range of salicylidene ligands, SaIH, were synthesised according to the Schiff-base reaction. These organic ligands were synthesized as potential bifunctional chelators between the tricarbonyl radionuclide and the biologically active directing molecule. The ligands contain various amine compounds which were coordinated to the imine nitrogen atom on the salicyclidene "backbone". The imino substituents consisted of aromatic, aliphatic and biologically active moieties with varying steric, electronic and biological properties and included amines such as m-toluidine, 3-methylbutylamine, aniline, histamine, tryptamine, tyramine etc. The ligands were characterized via NMR and IR spectroscopy. A single crystal X-ray diffraction study of the ligands was reported and revealed the various orientations of the substituents relative to the salicylidene backbone. The reported X-ray crystallographic structure determinations included the following ligands: 2-(m-tolyliminomethyl)phenol, 5- methyl-2-(m-tolyliminomethyl)phenol, 4-fluoro-2-(m-tolyliminomethyl)phenol, 2-(4-nitrophenyliminomethyl) phenol, 2-[(4-hydroxyphenyl)iminomethyl]-5-methylphenol, 2-[(2- imidazol-4-yl)ethyliminomethyl]-5-methylphenol, 2-[(2-indol-3-yl-ethyl)iminomethyl]-5- methylphenol, 2-(9-ethylcarbazol-3-yliminomethyl)-5-methylphenol, 2-[2-(4-hydroxy- phenyl)ethyliminomethyl]-5-me, Afrikaans: Renium(I) en tegnesium(I) trikarbonielkomplekse het betekenisvolle potensiaal as model kerngeneesmiddels wat gebruik sou kon word as terapeutiese- en beeldingsagente. 99mTegnesium word spesifiek In meer as 80% van alle radiofarmaseutiese middels as diagnostiese middel gebruik. Die bioverspreiding van "n potensiële radiofarmaseutiese middel kan in beginsel gemanipuleer word deur die koërdinasie van "n biologies-aktiewe verbinding aan die radionuklied. 'n Primêre doel van hierdie studie was om beter insig in die chemiese, koërdinatiewe en kinetiese gedrag van fac-[M(CO)3t (M = Tc, Re) komplekse te verkry. Met hierdie as uitgangspunt, is daar eerstens "n reeks salisielidien vry ligande, SaIH, met behulp van die Schiff-basis reaksie gesintetiseer. Hierdie organiese ligandstukture is gesintetiseer om potensieel as multifunksionele groepe tussen die trikarboniel radionuklied en die biologies aktiewe molekuul op te tree. Die ligande bevat verskeie amienverbindings wat aan die imien stikstofatoom op die salisielidien 'ruggraat' gekoordineer is. Die iminosubstituente bestaan uit aromatiese, alifatiese en biologies aktiewe onderdele met verskillende steriese, elektroniese en biologiese eienskappe en het die volgende ingesluit: m-toluïdien, 3- metielbutielamien, anilien, histamien, triptamien, tiramien ens. Die ligande is gekarakteriseer deur middel van KMR en IR spektroskopie. Enkelkristal X-straaldiffraksiestudies is uitgevoer en het gefokus op die verskeie oriëntasies van die substituente ten opsigte van die salisielidienruggraat. Die verbindings wat met behulp van enkelkristal X-straalkristallografie ondersoek is, sluit die volgende ligande in: 2-(m-tolieliminometiel)fenol, 5-metiel-2-(mtolieliminometiel )fenol, 4-fluoro- 2-(m-tolieliminometiel )fenol, 2-(4- nitrofenieliminometiel)- fenol, 2- [(4-hydroksifen yl)iminometiel] -5-metielfenol , 2- [(2-imidasol-4- iel)etieliminometiel] -5-metielfenol, 2- [(2-indol- 3-iel-etiel )iminometiel] -5-metielfenol , 2-(9-etie, National Research Foundation (NRF), University of the Free State, UFS Biomolecular Cluster, SASOL

English: Over the past few years, significant interest has been shown in Rhenium and Technetium tricarbonyl complexes of the form fac-[M(L,L’-bid)(CO)3(X)]n (M = Tc(I) and Re(I), (L,L’-bid) = different donor atom bidentate ligands, X = range of monodentate ligands), as potential diagnostic and therapeutic radiopharmaceuticals, respectively. This is mainly due to the discovery of the fac-[M(CO)3(H2O)3]+ synthon with the inert fac- [M(CO)3]+ core and the labile water molecules. These main characteristics make the synthons very attractive for application in nuclear medicine. Overall, the idea of this study was to gain further insight into the chemistry, coordination and kinetic behaviour of complexes containing the fac-[M(CO)3]+ core. From this idea, it was decided to synthesize a few novel ligand systems. This include N-benzylindole- 2,3-dione, N,N’-bis(2-pyridylmethyl)-2-aminoethanol, N,N’-bis(2-pyridylmethyl)-2-aminopropanol, N,N’-bis(2-pyridylmethyl)-2-aminobutanol, N’-(2-(1H-imidazol-4-yl)ethyl)- N3,N3-bis(pyridine-2-ylmethyl)-propane-1,3-diamine, 2-(3-(bis(pyridin-2-yl)methyl)- amino)propylamino)-acetic acid, N-(2-(1H-imidazol-4-yl)ethyl)pyrrolidine-2-carboxamide, N’-(2-(1H-imidazol-4-yl)ethyl)benzohydrazide and N-(pyridin-2-ylmethyl)nicotinamide. Some of these ligands were successfully coordinated to the fac-[Re(CO)3]+ core as well. The ligand systems, as well as these Rhenium(I) compounds, were sent for in vitro testing. The ligand systems synthesized were designed with the idea to be potentially biologically active by itself as well. A range of tricarbonyl complexes, of the form fac-[Re(L,L’-bid)(CO)3X], were synthesized by using a wide variety of bidentate ligands (L,L’-bid), with systematically chosen donor atoms. The bidentate ligands include 2,2’-bipyridine-3,3’-dicarboxylic acid, 2,5-pyridinedicarboxylic acid, 8-hydroxyquinoline, 5-chloro-8-hydroxyquinoline, 5,7-dimethyl-8-hydroxyquinoline, tropolone, isatin, 5-nitroisatin, 5-(trifluoromethoxy)- isatin, b, Afrikaans: Die laaste paar jaar het die belangstelling in Renium en Tegnesium trikarboniel komplekse, fac-[M(CO)3]+ (M = Tc(I) en Re(I)), beduidend toegeneem as potensiële diagnostiese en terapeutiese radiofarmaseutiese middels onderskeidelik. Dit is grotendeels agv die ontdekking van die fac-[M(CO)3(H2O)3]+ moïeteit. Verskeie belowende komplekse, wat die trikarboniel moïeteit bevat, is al gesintetiseer en twee van die hoof eienskappe wat die moïeteit so aantreklik maak vir die gebruik in kliniese medisyne, is die inerte fac-[M(CO)3]+ kern en die labiele water molekule. Die algehele motief van die studie was om meer inligting en beter insig ten opsigte van die chemiese, koördinatiewe en kinetiese gedrag van die fac-[M(CO)3]+ tipe komplekse te verkry. Vanaf hierdie uitgangspunt, is daar besluit om `n reeks nuwe vry ligande te sintetiseer, om te gebruik as potensiële biologies-aktiewe verbindings self, en om te koordineer met fac-[Re(CO)3]+ om sodoende `n potensiële aktiewe kompleks te verkry. Die ligande sluit in N-bensielindol-2,3-dioon, N,N’-bis(2-piridielmetiel)-2-aminoetanol, N,N’-bis(2-piridielmetiel)-2-aminopropanol, N,N’-bis(2-piridielmetiel)-2-aminobutanol, N’- (2-(1H-imiedasool-4-iel)etiel)-N3,N3-bis(piridien-2-ielmetiel)-propaan-1,3-diamien, 2-(3- (bis(piridien-2-iel)metiel)amino)propielamino)-asynsuur, N-(2-(1H-imiedasool-4- iel)etiel)pirrolidien-2-karboksamied, N’-(2-(1H-imiedasool-4-iel)etiel)bensohidrasied en N-(pyridin-2-ielmetiel)nikotinamied. Sommige van die ligande is suksesvol gekoördineer met die fac-[Re(CO)3]+ moïeteit en die ligand sisteme sowel as die Rhenium(I) komplekse is gestuur vir in vitro toetse. `n Reeks trikarboniel komplekse, fac-[Re(L,L’-bid)(CO)3X], is gesintetiseer met `n wye reeks bidentate ligande (L,L’-bid) met sistematies gekose donor atome. Die bidentate ligande sluit in 2,2’-bipiridien-3,3’-dikarboksielsuur, 2,5-piridiendikarboksielsuur, 8- hidroksiequinolien, 5-chloro-8-hidroksiequinolien, 5,7-dimetiel-8-hidroksiequinolien