Sökning: "superexchange"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet superexchange.

  1. 1. The Fate of Electronically Excited States : Ultrafast Electron and Energy Transfer in Solvated Donor-Acceptor Systems

    Författare :Staffan Wallin; Leif Hammarström; Jan Davidsson; Eric Vauthey; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; Electron transfer; Energy transfer; Anisotropy; Porphyrin; Ruthenium tris-bipyridine; Superexchange; Supramolecular; Donor-Acceptor; Charge transfer state; S2 state; Ultrafast; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : Processes where a molecule absorbs visible light and then disposes of the excess energy via electron/energy transfer reactions have an important role both in nature (e.g. in photosynthesis) and in many technical applications (e.g. LÄS MER

  2. 2. Synthesis, Nuclear Structure, and Magnetic Properties of some Perovskite Oxides

    Författare :Mehreteab Tseggai; Per Nordblad; Roland Tellgren; Torbjörn Gustafsson; Uppsala universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Materials science; Magnetic Perovskites; Neutron powder diffraction; SQUID; Synthesis; Nuclear structure; Antiferromagnetism; Ferromagnetism; Superexchange; Double exchange; Colossal magnetoresistance; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Sammanfattning : Synthesis, nuclear structure, and magnetic properties of the perovskites: Nd0.7-xMgxSr0.3MnO3 (x=0.0, 0. LÄS MER

  3. 3. Triplet Excitation Energy Transfer in Donor-Bridge-Acceptor Systems: Experimental and Theoretical Investigations

    Författare :Mattias P Eng; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; self-assembled monolayer; density functional theory; triplet excitation energy transfer; gold porphyrin; electron transfer; spectroscopy; superexchange; electronic coupling;

    Sammanfattning : This thesis is a contribution to the understanding of bridge mediation of electron exchange processes in Donor-Bridge-Acceptor (D-B-A) systems. The field of research is relevant for the development and optimization of dye-sensitized solar cells, artificial photosynthesis, and the possible future development of molecular electronic devices. LÄS MER

  4. 4. Tuning of Energy and Electron Transfer Rates in Donor-Bridge-Acceptor Systems

    Författare :Karin Pettersson; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron transfer; electronic coupling; paramagnetic species; superexchange; Donor-bridge-acceptor system; spectroscopy.; porphyrin; sequential electron transfer; Förster energy transfer; energy transfer;

    Sammanfattning : The intramolecular processes of Donor-Bridge-Acceptor (D-B-A) systems have been investigated by spectroscopic methods. The systems consist of porphyrin donors and acceptors linked by oligo-p-phenyleneethynylene bridges. LÄS MER

  5. 5. Tuning electron transfer reactions by selective excitation in porphyrin-acceptor assemblies

    Författare :Mikael Andersson; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Physics; Fysik; Physics; Fysik; Physical Chemistry; fysikalisk kemi;

    Sammanfattning : This thesis concerns electron transfer reactions from different excited states in porphyrins, and the effect of changing the energy of the link connecting the donor and acceptor. Photoinduced electron transfer, and subsequent processes were studied using ultrashort laser pulses and nanosecond laser flash photolysis. LÄS MER