Sökning: "dioxygen"

Visar resultat 1 - 5 av 15 avhandlingar innehållade ordet dioxygen.

  1. 1. X-ray spectroscopy on diatomic and cationic molecules

    Författare :Ludvig Kjellsson; Jan-Erik Rubensson; Marcus Agåker; Monica Turcato; Michael Meyer; John Bozek; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray absorption spectroscopy; resonant inelastic X-ray scattering; cationic molecule; dinitrogen; dioxygen; carbon monoxide; aqueous hydroxyl radical; lifetime-vibrational interference; RIXS; XAS; LVI; N2; O2; CO; H2O; OH;

    Sammanfattning : X-ray spectroscopy have been used to study the electronic structure of diatomic and cationic molecules. X-ray absorption spectra of the molecular cations N2+, O2+, and CO+ have been measured. LÄS MER

  3. 2. Reaction Mechanisms of Metalloenzymes and Synthetic Model Complexes Activating Dioxygen : A Computational study

    Författare :Valentin Georgiev; Per E.M. Siegbahn; Sam de Visser; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; catalysis; density functional theory; extradiol; intradiol; dioxygenases; oxygen; biomimetic complexes; heme; spin transition; adipic acid; Chemical physics; Kemisk fysik; kvantkemi; Quantum Chemistry;

    Sammanfattning : Quantum chemistry has nowadays become a powerful and efficient tool that can be successfully used for studies of biosystems. It is therefore possibleto model the enzyme active-site and the reactions undergoing into it, as well as obtaining quite accurate energetic profiles. LÄS MER

  4. 3. Theoretical studies of mononuclear non-heme iron active sites

    Författare :Arianna Bassan; Per E. M. Siegbahn; Sason Shaik; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; enzyme catalysis; iron enzymes; Quantum chemistry; Kvantkemi;

    Sammanfattning : The quantum chemical investigations presented in this thesis use hybrid density functional theory to shed light on the catalytic mechanisms of mononuclear non-heme iron oxygenases, accommodating a ferrous ion in their active sites. More specifically, the dioxygen activation process and the subsequent oxidative reactions in the following enzymes were studied: tetrahydrobiopterin-dependent hydroxylases, naphthalene 1,2-dioxygenase and α-ketoglutarate-dependent enzymes. LÄS MER

  5. 4. Crystallography in Four Dimensions : Methods and Applications

    Författare :Gunilla Carlsson; Janos Hajdu; Dieter Oesterhelt; Vilmos Fülöp; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular biophysics; horseradish peroxidase; redox reactions; X-ray crystallography; haem catalysis; molecular movies; radiation damage; Molekylär biofysik; Molecular biophysics; Molekylär biofysik;

    Sammanfattning : The four-electron reduction of dioxygen to water is the most exothermic non-photochemical reaction available to biology. A detailed molecular description of this reaction is needed to understand oxygen-based redox processes. Horseradish peroxidase (HRP) is a haem-containing redox enzyme capable of catalysing the reduction of dioxygen to water. LÄS MER

  7. 5. Mimicking Nature – Synthesis and Characterisation of Manganese Complexes of Relevance to Artificial Photosynthesis

    Författare :Gustav Berggren; F. Magnus Anderlund; Leif Hammarström; Vincent Pecoraro; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Manganese; biomimetic; artificial photosynthesis; water splitting; homogeneous catalysis; Chemistry; Kemi; fysikalisk kemi; Physical Chemistry;

    Sammanfattning : The development of efficient catalyst for water oxidation is of paramount importance to artificial photosynthesis, but before this can be achieved a deeper understanding of this reaction is essential. In nature this reaction occurs in a tetranuclear Mn-cluster which serves as the work-horse of oxygenic photosynthesis. LÄS MER