Sökning: "Substitution effects"
Visar resultat 1 - 5 av 207 avhandlingar innehållade orden Substitution effects.
1. Green consumption energy use and carbon dioxide emission
Sammanfattning : The aim of this thesis is to explore the quantitative potential to reduce energy requirements and CO2 emissions through changed patterns of consumption, given unchanged levels of consumption expenditure. The thesis question is analysed using a systems analysis approach which in this case means that life cycle assessment data on energy requirements and CO2 emissions related to household consumption are combined with a financial and behavioural analysis to make sure that the budget constraint is kept and that both the first and second order effects of adopting a green consumption pattern are analysed. LÄS MER
2. Concerted or Stepwise? : β-Elimination, Nucleophilic Substitution, Copper Catalysed Aziridination and Ruthenium Catalysed Transfer Hydrogenation Studied by Kinetic Isotope Effects and Linear Free-Energy Relationships
Sammanfattning : This thesis describes the use of kinetic isotope effects, linear free energy relationships and stereochamical studies to distinguish between different mechanistic alternatives and to obtain information about transition state structure.In the first part fluorine and deuterium kinetic isotope effects were determined for the base promoted HF elimination from 4-fluoro-4-(4’-nitrophenyl)butane-2-on. LÄS MER
3. Palladium-Catalyzed Nucleophilic Substitution of Alcohols : Mechanistic Studies and Synthetic Applications
Sammanfattning : This thesis deals with the palladium-catalyzed nucleophilic substitution of π-activated alcohols in which the C–O bond of a non-manipulated hydroxyl group is cleaved. The thesis is divided in two chapters describing two different catalytic systems. LÄS MER
4. Isotopes as Mechanism Spies : Nucleophilic Bimolecular Substitution and Monoamine Oxidase B Catalysed Amine Oxidation Probed with Heavy Atom Kinetic Isotope Effects
Sammanfattning : This thesis concerns the study of reaction mechanisms by means of kinetic isotope effects (KIEs). Studies of the nucleophilic bimolecular substitution (SN2) reaction had the dual purpose of improving our fundamental understanding of molecular reactivity and assessing the ability of kinetic isotope effects to serve as mechanistic tools. LÄS MER
5. Structural and Electrical Transport Properties of Doped Nd-123 Superconductors
Sammanfattning : It is generally believed that one of the key parameterscontrolling the normal state and superconducting properties ofhigh temperature superconductors is the charge carrierconcentrationpin the CuO2planes.By changing the non-isovalent dopingconcentration on the RE site as well as the oxygen content in(RE)Ba2Cu3O7−δ, an excellent tool is obtained tovary the hole concentration over a wide range from theunderdoped up to the overdoped regime. LÄS MER