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The synthesis and characterisation of a selection of asymmetric and symmetric a-diimine ligands are described, including their single crystal X-ray structures and those of the imino-ketone intermediates used in their synthesis. The coordinated Fe(II) dichloride complexes of a series of a-diimine ligands used as ATRP catalysts are reported, along with the crystal structure of [FeCl2(2,6-diisopropylphenyl)2DABH2] and [FeCl2(c-hexyl)2DABPh2]. The isolation of high molecular weight polyethylene derived from (2-isopropylphenyl)2DABPh2 and MMAO in an initial attempt to react the tentatively formed [FeCl2(2-isopropylphenyl)2DABPh2] led to the development of AlCl3 a-diimine chemistry and the synthesis of a range of novel AlCl3 coordinated (2,6-diisopropylphenyl)2DABH2 complexes and 4,4’-m2{(N,N’-bis(2,6-diisopropylphenyl)- 2,2-dichloro-1,3,2-diazaalane}. The use of AlCl3 also led to the structure determination of [{ClSiMe2OAlCl2}2] obtained from a room-temperature depolymerisation reaction for silicone grease with AlCl3. The application of the a-diimine library developed to palladium dichloride, and the structure determination of a range of novel palladium dichloride complexes are also presented, with relation to structural changes to the a-diimine upon coordination. These trends are followed into the formation of monomethylated palladium chloride and Brookhart type ([PdMe(NCCH3)a-diimine]BAF) pro-catalyst complexes. A range of Brookhart type pro-catalyst were studied in relation to the effect of altering steric bulk at the a-carbon, H < Me < Ph on polymerisation activity. Progress made in developing low cost hardware for X-ray diffraction environmental control is described as well as the use of informatics to design and implement of an in-house structural database, accessible via a world-wide-web portal using SSL technology.

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The work reported in this thesis is a series of investigations designed to elucidate the nature of the olefin polymerisation reaction catalysed by a Ziegler-type system supported on magnesia and on rutile. All activation and polymerisation reactions were studied by direct vapour/solid or gas/solid interactions. Infrared spectroscopy was employed to present a qualitative picture of all stages of catalyst activation and to identify polymeric species formed when the catalyst was exposed to ethylene and propylene monomers. A quantitative investigation of catalyst activation on the magnesia support was undertaken using gravimetric and analytical techniques. In the light of these results a reaction scheme has been proposed for the production of active sites on the magnesia surface. In essentially similar scheme is proposed for activation of the rutile support. Polymerisation of ethylene and propylene monomers by the magnesia based catalyst was followed gravimetrically. A study of the process variables such as temperature, monomer pressure and the effects of feedstock impurities was undertaken in order to formulate a kinetic model for the system. Strong kinetic evidence is presented for mass transfer control of the polymerisation rate. Such a model was supported by studies of the nature of the polymer formed, which appeared as a coherent encapsulating film on the catalyst surface. In a further series of experiments the permeation properties of ethylene and propylene monomers in their corresponding polymers were investigated. It is proposed that the permeation parameters derived from these studies find parallels in the olefin polymerisation reaction and this is interpreted as further evidence for diffusion control of the polymerisation reaction.

This thesis is concerned with two sections: the first deals with the synthesis of quinolinones via a tandem VNS reaction. The second examines the aminocatalysis of the Baylis-Hillman reaction Chapter 1: Provides an overview of aromatic chemistry. Focus is on the separate mechanisms of the substitution of aromatic compounds. An overview of VNS chemistry is also included to provide a basis for the investigations carried out. Chapter 2: Describes the synthesis of a small library of 6/s-rutroaromaric compounds using the VNS reaction. An investigation into the cyclisation of the &amp;w-nitroaromatic compounds to a range of biologically interesting quinolinones is also described. Chapter 3: Introduces the concept of aminocatalysis and gives an overview of recent developments in the field including the Baylis-Hillman reaction, the reaction chosen for asymmetric catalyst development. Chapter 4: Is split into three sections the first describes an interesting solvent effect encountered during the course of the investigation. The second investigates the effect of the structure of secondary amines on the enantioselectivity of the reaction via iminium ion formation. The third section describes the investigation of the structure of Lewis bases on the enantioselectivity of the reaction.

Fischer Tropsch (FT) technology as a source of alternate fuels is unique. The FT products are of excellent quality and their environmental properties are valuable in increasing drive towards cleaner fuels. There was surge of interest in FT in the thirties and fifties (during the Second World War) and now again in last couple of years. Fischer Tropsch technology has a disadvantage of broad product spectrum. There is strong requirement of improvement in the optimization of reaction in order to get a maximum yield of high value commercial products, mainly high value molecular weight products, alcohols and short chain hydrocarbons. Most of the investigations reported in this thesis have dealt with study and possible modifications in the preparation and reaction conditions of previously studied CoMnOx catalyst. Co-precipitation method for preparation of this catalyst has been studied in detail. Precipitation by variable pH has been found to be better than constant pH. pH, ageing time of precipitates and temperature of precipitation mixture are very important parameters which affect the selectivity pattern of products. This selectivity pattern was found to be further influenced by reaction temperature and pressure during CO hydrogenation reaction. An improvement in the selectivities for CO hydrogenation reaction has been developed using a modified co-precipitated Co/Mn oxide catalyst. This modification was achieved by using two different metal promoters, i.e., Potassium and ruthenium. Addition of these promoters has influenced the catalytic properties in a variety of ways as was observed from characterization and reaction results. Addition of small quantity of potassium (0.15%), and ruthenium (0.1%) promoters shifted the product spectrum to long chain hydrocarbons along with decrease in methane selectivity. Further improvements in catalytic activity and selectivity were made by addition of two different types of activated carbons (wood and peat shell) into Co/Mn catalyst. Co and Mn impregnated on wood peat carbon were found to be highly selective for high molecular weight hydrocarbons along with low selectivity of CO₂ compared with pure CoMnOx catalyst. An increase in concentration of metals with these carbons showed an increase in selectivity of CO₂. One particular catalyst system of iron and manganese was studied with peat and wood carbons and was found to be highly selective for CO₂ formation. Alcohols, an important product of FT reaction are a good substitute to motor fuel which can enhance the octane number and can reduce the environmental pollution. Cobalt molybdenum sulphide is a patented catalyst system for alcohols synthesis. Present study has investigated the influence of transition metal promoters on selectivity pattern of this catalyst. Ti, Ni and Zr metals have been used as promoters. Addition of Ni and Ti into C0M0S2 have shown good catalytic activity but the major product was CO₂. Zr addition has shown less CO₂ and more hydrocarbons. Pure C0M0S2 catalyst was found to be better for synthesis of higher alcohols.