Search for dissertations about: " 2"

Found 4 swedish dissertations containing the words 2.

  2. 1. DNA Interactions with Chiral Polyaza-aromatic Ruthenium(II) Complexes

    Author : Per Lincoln; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; phenanthroline; binding geometry; binding isotherm; DNA; dppz; linear dichroism; intercalation; ruthenium; cooperative binding;

    Abstract : The binding to DNA of a series of chiral ruthenium complexes is studied with optical spectroscopy techniques, including isotropic absorption, linear dichroism (LD) and emission anisotropy as well as steady-state and time-resolved luminescence. The thesis focuses on the ìlight-switchî complex [Ru(phen)2dppz]2+ which binds to DNA by intercalation and luminesces when bound to DNA but not in pure buffer solution (phen=1,10-phenanthroline; dppz=dipyrido[3,2-a:2',3'-c]phenazine). READ MORE

  4. 2. Chiral Ruthenium Dipyrodiphenazine Complexes: DNA Binding and Excited State Relaxation

    Author : Björn Önfelt; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; polarization spectroscopy; DNA-probe; dppz; excited-state relaxation; intercalation; solvent relaxation; DNA-threading;

    Abstract : Ruthenium complexes with aromatic ligands have been extensively studied due to their interesting photophysical properties, including photophysics and electron transfer upon interaction with nucleic acids. For example, the broad absorption spectrum makes them suitable as antenna molecules in photochemical reaction systems and their ability to accept or donate electrons in their excited state could have potential in opto-electronical devices. READ MORE

  5. 3. Intramolecular electron transfer in DNA and ruthenium(II) systems

    Author : Johan Olofsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; solvent relaxation; light switch effect; dppz; electron transfer and hydrogen bond;

    Abstract : When ruthenium(II) complexes with heteroaromatic ligands absorb light, an electron is pushed from the metal ion out into one of the ligands, a process called metal-to-ligand-charge-transfer (MLCT). The resulting excited state can be used to initiate further electron transfer processes, or it can decay relatively slow back into the ground state with the emission of light. READ MORE

  6. 4. DNA Binding of Metal Complexes. A Spectroscopic Study of Trigonal Ru(II)phenanthroline Complexes and Uranyl(VI) Ion with Respect to Specific Interactions with DNA

    Author : Catharina Hiort; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; uranyl; nucleic acids; optical probes;

    Abstract : The interaction of metal complexes with nucleic acids has attracted attention owing to their potentials as optical probes, probes of chirality, and for use as artificial restriction enzymes. To understand the underlying mechanisms in these contexts we studied the binding to DNA of the enantiomers of two chiral ruthenium(II) metal complexes ([Ru(phen)3]2+ and [Ru(phen)2]2+DPPZ) phen=1,10-phenanthroline, DPPZ=dipyrido[3,2-a:2',3'-c]phenazine, and of the linear uranium(VI) complex, uranyl ([UO2]2+), using linear dichroism, circular dichroism and luminescence, as well as nuclear magnetic resonance spectroscopy. READ MORE