title: Influence of Protonation State on the Excited State Dynamics of a Photobiologically Active Ru(II) Dyad.
abstract: The influence of ligand protonation on the photophysics of a ruthenium (Ru) dyad bearing the 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline (ippy) ligand was investigated by time-resolved transient absorption spectroscopy. It was found that changes in the protonation state of the imidazole group led to changes in the electronic configuration of the lowest lying excited state. Formation of the fully deprotonated imidazole anion resulted in excited state signatures that were consistent with a low-lying intraligand (IL) triplet state. This assignment was supported by time-dependent density functional theory (TDDFT) calculations. IL triplet states have been suggested to be potent mediators of photodynamic effects. Thus, these results are of interest in the design of Ru metal complexes as photosensitizers (PSs) for photodynamic therapy (PDT).
authors.affiliation: Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena , Helmholtzweg 4, 07743 Jena, Germany.|Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Reichardt
authors.affiliation: Department of Chemistry, Acadia University , Wolfville NS B4P 2R6, Canada.
authors.forename: Tariq
authors.initials: T
authors.lastname: Sainuddin
authors.affiliation: Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Wächtler
authors.affiliation: Department of Chemistry, Acadia University , Wolfville NS B4P 2R6, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Monro
authors.affiliation: Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena , Helmholtzweg 4, 07743 Jena, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kupfer
authors.affiliation: Gdansk University of Technology , Narutowicza 11/12, 80-233 Gdansk, Poland.
authors.forename: Julien
authors.initials: J
authors.lastname: Guthmuller
authors.affiliation: Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena , Helmholtzweg 4, 07743 Jena, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Gräfe
authors.affiliation: Department of Chemistry, Acadia University , Wolfville NS B4P 2R6, Canada.|Department of Chemistry & Biochemistry, University of North Carolina at Greensboro , Greensboro, North Carolina 27402, United States.
authors.forename: Sherri
authors.initials: S
authors.lastname: McFarland
authors.affiliation: Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena , Helmholtzweg 4, 07743 Jena, Germany.|Leibniz Institute of Photonic Technology (IPHT) , Albert-Einstein-Straße 9, 07745 Jena, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dietzek
mesh_terms: D008024:Ligands; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010618:Phenanthrolines / Q000737:chemistry*; D017319:Photosensitizing Agents / Q000737:chemistry*; D011522:Protons; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D010618:Phenanthrolines; D017319:Photosensitizing Agents; D011522:Protons; D012428:Ruthenium