Sökning: "carbenium"

Hittade 3 avhandlingar innehållade ordet carbenium.

  1. 1. Investigation of [N-X-N]+ and [N-C-N]+ complexes in solution : Exploring Geometry, Stability and Symmetry

    Författare :Alavi Karim; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; three center four electron; halonium; carbenium; carbonium; pentavalent; symmetry; NMR; variable temperature; counterion; isotopic perturbation of equilibrium;

    Sammanfattning : Halogen bonding is a weak interaction. In this thesis the three center four electron halogen bond, [N−X−N]+, has been studied. The lighter halogens form highly unstable halonium ions that are reactive towards nucleophiles and their complexes were therefore investigated at low temperatures. LÄS MER

  3. 2. Organomolybdenum Complexes in Organic Synthesis- New methods for the Preparation of Cationic Diene Complexes and Applications to Synthesis

    Författare :Emelie Bjurling; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Organic chemistry; indoles; carbenium ions; hexafluoroisopropanol; hydride abstraction; molybdenum; cationic diene complexes;

    Sammanfattning : Indolyl substituted pyranyl- and cyclohexenyl molybdenum complexes were synthesised through stereoselective nucleophilic addition of indoles to the corresponding cationic 2H-pyran or cyclohexadiene molybdenum complex. Decomplexation of an allylic molybdneum complex by treatment with iodine gave 1-(4-iodo-2-cyclohexenyl)-1H-indole-3-carbonitrile in high regio-selectivity. LÄS MER

  4. 3. Catalysis for Lean NOx Reduction - Aspects of Catalyst Synthesis and Surface Acidity

    Författare :Hanna Härelind Ingelsten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lean NOx reduction; silica; alumina; FTIR; surface acidity; model catalysts; platinum; HZSM-5; w o microemulsion; aluminum-silicate; hydrocarbon;

    Sammanfattning : From both economic and environmental perspectives it is desirable to reduce the consumption of fossil fuels. One route to increase the fuel efficiency for vehicles is operation in oxygen excess. However, a major problem with this technique is the lean environment, which obstructs catalytic reduction of nitrogen oxides (NOx) to harmless nitrogen. LÄS MER