The synthesis, structure, and reactivity of titanium bis(diimine) complexes supported by 1,2-alternate dimethylsilyl-bridged p-tert-butylcalix[4]arene dianion and 2,2' methylene-bridged 4-methyl, 6-tertbutyl phenol ligands is reported. The molecular structure of [(DMSC)Ti(bpy)2] (28) and [(MBMP)Ti(bpy)2] (55) was characterized by X-ray crystallography. Complexes [(DMSC)Ti(bpy)2] (28), [(DMSC)Ti(dmbpy)2] (29), and [(DMSC)Ti(phen)2] (30) undergoes light-assisted reactions with two or more equivalents of (C6H5)2CO or (p-MeC6H4)2CO to give the corresponding 1-aza-5-oxa-titanacyclopentene complexes 37-42. Similar reactivity was observed with [(MBMP)Ti(bpy)2] (55), [(MBMP)Ti(dmbpy)2] (56), and [(MBMP)Ti(phen)2] (57). The molecular structure of [(MBMP)Ti{kappa-3-OC(C6H5)2C10H7N2}{OCH(C6H5)2}] (58) was characterized by 1H and 13C NMR as well as X-Ray crystallography.

Thesis (MSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In this thesis the synthesis of a wide range of model and siloxane functionalized N-(n-propyl)-1-(2-pyridyl and quinolyl)-imine ligands (L1-L6) are described. Functionalized ligands (L4-L6) were obtained by the reaction of the pyridyl and quinolyl aldehydes with 3-aminopropyltriethoxysilane. Model ligands were characterized by FT-IR and 1H NMR spectroscopy while 13C{1H} NMR spectroscopy was additionally used for functional ligand characterization. Functionalized complexes of both Pd(II) and Cu(I) were found to be more thermally stable than their model counterparts. Overall the model Pd(II) complexes showed a higher thermal stability than the model Cu(I) complexes. Ligands (L1-L6) were reacted with either Pd(II) or Cu(I) metal precursors to produce both the model and functionalized Pd(II) (C1-C6) and Cu(I) (C7-C12) metal complexes. These metal complexes were all characterized by FT-IR spectroscopy, 1H NMR and UV/Vis spectroscopy for the model Cu(I) complexes. Functionalized complexes were additionally characterized with 13C{1H} NMR spectroscopy. Siloxane functionalized complexes of Pd(II) and Cu(I) were immobilized on MCM-41 and SBA-15 silica materials to produce heterogenized immobilized catalysts. These immobilized catalysts were characterized by a wide range of solid state techniques including: BET nitrogen adsorption/desorption, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), ICP-AES, FT-IR spectroscopy, powder XRD and solid state 13C{1H} NMR spectroscopy. ICP-AES and BET surface analysis showed that better complex immobilization occurred for SBA-15 supported materials despite SBA-15 having a significantly lower surface area than MCM-41. This higher immobilization was ascribed to the larger pore sizes of SBA-15 (50 Å) vs. that of MCM-41 (26 Å). Immobilized catalysts were tested for the oxidation of benzyl alcohol to benzaldehyde. Immobilization had a positive effect on the catalytic activity of the Pd(II) complexes with higher conversions being observed for immobilized Pd(II) catalysts when compared to their model analogues. Overall the MCM-41 immobilized Pd(II) catalysts showed a higher increase in activity than SBA-15 immobilized catalysts. For Ti-doped supports a generally higher activity was seen for the Ti-SBA-15 system. The Cu(I) systems however were not as effective in the oxidation reactions. / AFRIKAANSE OPSOMMING: In hierdie tesis word die sintese van `n wye reeks model sowel as gefunksioneerde N-(n-propiel)-1-(2-piridiel en kinoliel)-imien ligande (L1-L6) beskryf. Gefunksioneerde ligande (L4-L6) is gevorm deur die reaksie van piridiel en kinoliel aldehied met 3-amniopropieltriëtoksiesilaan. Model ligande is gekaraktariseer deur FT-IR en 1H KMR spektroskopie terwyl 13C{1H} KMR spektroskopie addisioneel gebruik is vir die karaktarisering van die gefunksioneerde ligande. Ligande (L1-L6) is gereageer met Pd(II) of Cu(I) metaal voorgangers om beide model sowel as gefunksioneerde Pd(II) (C1-C6) en Cu(I) (C7-C12) metaal komplekse op te lewer. Hierdie metaal komplekse is almal gekaraktariseer deur FT-IR, 1H KMR en UV/Vis spektroskopie vir die model Cu(I) komplekse. Gefunksionalseerde komplekse is addisioneel gekaraktariseer deur gebruik te maak van 13C{1H} KMR spektroskopie. Dit is gevind dat gefunksionaliseerde komplekse van beide Pd(II) sowel as Cu(I) termies meer stabiel was as hulle ooreenstemmende model komplekse. Oor die algemeen het die Pd(II) komplekse hoër termiese stabiliteit as die Cu(I) komplekse getoon. Siloksaan gefunksioneerde komplekse van Pd(II) en Cu(I) is geimmobiliseer op MCM-41 en SBA-15 silika materiale om heterogene geimmobiliseerde katalisatore op te lewer. Hierdie geimmobiliseerde katalisatore is gekaraktariseer deur van `n wye reeks vaste toestand tegnieke gebruik te maak. Hierdie suit in: SEM, TGA, ICP-AES, FT-IR, poeier XRD en vaste toestand 13C{1H} KMR spektroskopie. ICP-AES en BET oppervlak analieses het getoon dat beter kompleks immobilisering vir die SBA-15 silika material plaas gevind het, ondanks die feit dat SBA-15 `n laer oppervlak area beskik. Hierdie hoër graad van immobilisering is toegeskryf aan die groter poriegrootte van SBA-15 (50 Å) teenoor die van MCM-41 (26 Å). Geimmobiliseerde katalisatore is getoets in die oksidasie van bensielalkohol na bensaldehied. Dit is gevind dat die immobilisering van die Pd(II) komplekse op die silika materiaal `n positiewe uitwerking op die aktiwiteit van die katalitiese van die komplekse gehad het. Die hoogste toename in aktiwiteit is gesien vir geimmobiliseerde Pd(II) katalisatore wanneer hulle met hul ooreenstemmende model komplekse vergelyk is. Oor die algemeen is gevind dat MCM-41 geimmobiliseerde Pd(II) katalisatore n hoër toename in aktiwiteit getoon het as die van SBA-15. Vir die Ti-gedokterde silika materiale het die Ti-SBA-15 sisteem oor die algemeen `n hoër aktiviteit getoon as die Ti-MCM-41 sisteem. Die Cu(I) sisteme was egter nie so effektief in oksidasie reaksies nie.

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Computational chemistry has gained interest as a characterization tool to predict photoluminescence, reactivity and structural properties of organic and transition metal complexes. With the rise of methods including relativity, these studies have been expanded to the accurate modeling of luminescence spectra of complexes with considerable spin-orbit splitting due to heavy metal centers as well as the reaction pathways for these complexes to produce natural products such as hydrogen gas. These advances have led to the synthesis and utility of more effective catalysis as well as the development of more effective organic light emitting diodes (OLEDs) through the incorporation of organometallic complexes as emitters instead of typical organic emitters. In terms of significant scientific advancement presented in this work is in relation to the discovery of significant spin-orbit splitting in a gold(I) alkylphosphine complex, where the splitting results in the states that emit in different colors of the visible region of the electromagnetic spectrum. This work also reveals the discovery both computationally and experimentally, of a genuine polar-covalent bond between two-closed shell metals. This work highlights a complex with an incredibly short gold(I) – copper(I) intermetallic distance leading to a vibrational frequency and dissociation energy that is on par with those of other systems with single-bonded metal centers. Lastly, this work outlines a strategy for the production of hydrogen gas through the use of trinuclear cyclic coinage metal complexes as catalysis to split hydrohalic acids.