Sökning: "Porphyrin"

Visar resultat 1 - 5 av 87 avhandlingar innehållade ordet Porphyrin.

  1. 1. Theoretical studies of porphyrin proteins

    Författare :Emma Sigfridsson; Teoretisk kemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; molecular mechanics; quantum chemical calculations; electrostatic potential charges; atomic charges; ferrochelatase; cytochrome; myoglobin; Porphyrin; haem; QM MM; reorganisation energy; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Sammanfattning : Different aspects of porphyrin proteins have been studied with theoretical methods. For example, we have studied: - The importance of hydrogen bonds for the discrimination between carbon monoxide and molecular oxygen by myoglobin, the oxygen carrier in muscles, modelling the active site both in vacuum and in the protein matrix - The inner-sphere reorganisation energy during electron transfer for cytochromes compared to other electron-transfer proteins, such as blue copper proteins and Fe-S clusters - The role of porphyrin distortions in the reaction mechanism of ferrochelatase, the enzyme that inserts an iron ion into protoporphyrin IX to make haem - The interaction between different metal sites in ferrochelatase In these studies we have used density functional theory, classical force field methods, and a combination of quantum chemistry and molecular mechanics. LÄS MER

  2. 2. Kinetic studies of vanadyl etioporphyrin hydrodemetallization

    Författare :Feixiang Long; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kinetics; hydroprocessing; metal porphyrin; hydrometallization; hydrotreeating; vanadyl porphyrin; porphyrin; CoMo catalyst; etioporphyrin;

    Sammanfattning : .... LÄS MER

  3. 3. Intramolecular processes in porphyrin-based donor-bridge-acceptor systems

    Författare :Karin Pettersson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Donor-bridge-acceptor system; paramagnetic species; spectroscopy; porphyrin; super-exchange electron transfer; sequential electron transfer;

    Sammanfattning : .... LÄS MER

  4. 4. Energy and Electron Transfer in Porphyrin-Based Donor--Bridge--Acceptor Systems

    Författare :Kristine Kilså; Chalmers University of Technology; []
    Nyckelord :electron transfer; electronic coupling; donor--bridge--acceptor systems; quantum mechanical calculations; enhanced intersystem crossing; ligand and solvent effects; bridge mediation; energy transfer; porphyrin;

    Sammanfattning : The photophysical properties of supramolecular donor--bridge--acceptor systems have been investigated by spectroscopic and quantum mechanical methods. The systems consist of porphyrin donor and acceptor moieties linked by bridging chromophores of varying excitation energy, and are shown to be geometrically well-defined in terms of length and rotational conformation. LÄS MER

  5. 5. Multimodal Porphyrin-Based Conjugates : Synthesis and characterization for applications as amyloid ligands, photodynamic therapy agents and chiroptical materials

    Författare :Katriann Arja; Peter Nilsson; Peter Konradsson; Fredrik Almqvist; Linköpings universitet; []

    Sammanfattning : Organic compounds that interact both with certain biological targets and display specific photophysical properties can be utilized as molecular tools to visualize and possibly effect disease related processes taking place in living organisms. In this regard, porphyrins are a class of naturally occurring molecules that possess intriguingly interesting photophysical properties where they can act as luminescent probes by emitting detectable light, as well as photosensitizers in the light mediated therapy called photodynamic therapy. LÄS MER