Sökning: "Electron transfer"

Visar resultat 21 - 25 av 524 avhandlingar innehållade orden Electron transfer.

1. 21. Proton-Coupled Electron Transfer from Hydrogen-Bonded Phenols

   Författare :Tania Irebo; Leif Hammarström; James M. Mayer; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Proton-coupled electron transfer; phenol oxidation; hydrogen bonds; artificial photosynthesis; promoting vibrations; proton transfer; laser flash-quench; transient absorption.; Physical chemistry; Fysikalisk kemi; Fysikalisk kemi; Physical Chemistry;

   Sammanfattning : Proton-coupled electron transfer (PCET) is one of the elementary reactions occurring in many chemical and biological systems, such as photosystem II where the oxidation of tyrosine (TyrZ) is coupled to deprotonation of the phenolic proton. This reaction is here modelled by the oxidation of a phenol covalently linked to a Ru(bpy)32+-moitey, which is photo-oxidized by a laser flash-quench method. LÄS MER

3. 22. Bridge Mediated Electron Transfer in Conjugated and Cross-Conjugated Donor-Acceptor Compounds

   Författare :Erik Göransson; Leif Hammarström; Hans-Christian Becker; Michael R. Wasielewski; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electron transfer; Ultrafast; Long-range; Intervalence charge transfer; cross conjugation; hyperconjugation; Physical Chemistry; Fysikalisk kemi;

   Sammanfattning : Detailed understanding of electron transfer reactions is important in many aspects of chemistry, biology and solar energy conversion.The main aim of this thesis is to provide further insight into electron transfer through highly conjugated bridge structures. LÄS MER

4. 23. Porphyrin-Based Donor-Bridge-Acceptor Systems: Intrinsic Excited State Deactivation and Intramolecular Energy/Electron Transfer Reactions

   Författare :Joakim Andreasson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spectroscopy; superexchange; mediation; energy transfer; porphyrins; conformational gating; conformational distortions; electron transfer;

   Sammanfattning : Intramolecular energy and electron transfer reactions have been studied between porphyrin donor and acceptor moieties. The porphyrin units are covalently linked together by one of three different bridging chromophores to constitute the series of D-B-A systems. LÄS MER

5. 24. Exploring Electron Transfer Dynamics of Novel Dye Sensitized Photocathodes : Towards Solar Cells and Solar Fuels

   Författare :Lei Zhang; Leif Hammarström; Yiying Wu; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electron transfer; Laser spectroscopy; Femtosecond spectroscopy; Transient absorption; NiO; DSSCs; DSSFDs; Charge separation; Solar energy conversion; Nanosecond photolysis; Photophysics; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

   Sammanfattning : The design of dyes for NiO-based dye-sensitized solar cells (DSSCs) has drawn attention owing to their potential applications in photocatalysis and because they are indispensable for the development of tandem dye-sensitized solar cells. The understanding of the electron transfer mechanisms and dynamics is beneficial to guide further dye design and further improve the performance of photocathode in solar cells and solar fuel devices. LÄS MER

7. 25. Nitric Oxide Reductase from Paracoccus denitrificans : A Proton Transfer Pathway from the “Wrong” Side

   Författare :Ulrika Flock; Pia Ädelroth; Simon de Vries; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; denitrification; nitric oxide reductase; heme copper oxidase superfamily; divergent member; proton transfer; electron transfer; single turnover; spectroscopy; periplasm; glutamate; proton pathway; Biochemistry; Biokemi; biokemi; Biochemistry;

   Sammanfattning : Denitrification is an anaerobic process performed by several soil bacteria as an alternative to aerobic respiration. A key-step in denitrification (the N-N-bond is made) is catalyzed by nitric oxide reductase (NOR); 2NO + 2e- + 2H+ → N2O + H2O. LÄS MER