928014-00-0Relevant academic research and scientific papers
Novel Ru(ii) sensitizers bearing an unsymmetrical pyridine-quinoline hybrid ligand with extended π-conjugation: Synthesis and application in dye-sensitized solar cells
Vougioukalakis, Georgios C.,Stergiopoulos, Thomas,Kontos, Athanassios G.,Pefkianakis, Eleftherios K.,Papadopoulos, Kyriakos,Falaras, Polycarpos
, p. 6582 - 6591 (2013)
Heteroleptic ruthenium(ii) sensitizers DV42 and DV51, encompassing a novel unsymmetrical pyridine-quinoline hybrid ligand with extended π-conjugation, were synthesized, characterized, and utilized in nanocrystalline dye-sensitized solar cells. Due to the extended conjugation of DV42 and DV51, the absorption of the corresponding sensitized TiO2 films extends into the red spectral range, shifted by 30-40 nm relative to the absorption of TiO 2 films sensitized with the standard Z907 ruthenium(ii) dye. Contact angle measurements of DV42- and DV51-sensitized TiO2 films suggest that these films are hydrophilic with contact angle values commonly observed upon sensitization with the standard N3 ruthenium(ii) dye. Electrochemical studies of the novel ruthenium(ii) dyes show that their first oxidation potentials lie well below the I-/I3- redox potential allowing easy regeneration. The excited-state oxidation potentials of both dyes lie above the TiO2 conduction band, permitting efficient electron injection from the excited dye molecules into the semiconductor conduction band. Liquid electrolyte dye-sensitized solar cells incorporating DV42- or DV51-sensitized TiO2 photoelectrodes afford overall power conversion efficiencies of 3.24 or 4.36% respectively. These efficiencies are up to 56% of the power conversion efficiencies attained by TiO2 photoelectrodes sensitized by the benchmark Z907 ruthenium(ii) dye under similar experimental conditions.
Substituted pyridine-quinoline ligands as building blocks for neutral rhodium(III) complexes. Synthesis, structural characterization studies and anti-platelet activity towards the Platelet-Activating Factor (PAF)
Andreopoulou, Aikaterini K.,Demopoulos, Constantinos A.,Giannopoulos, Panagiotis,Kallitsis, Joannis K.,Margariti, Antigoni,Papakonstantinou, Vasiliki D.,Philippopoulos, Athanassios I.,Schnakenburg, Gregor,Stamatakis, George M.
, (2020)
The Friedl?nder condensation reaction was employed to synthesize the new bidentate ligands namely 6-bromo-4-phenyl-2-pyridin-2-yl-quinoline (1) and 4-(4-phenyl-2-(pyridin-2-yl)quinolin-6-yl)phenol (2). These compounds were fully characterized including the X-ray structures of 1 and the protonated form of 2, i.e. 2·HCl·H2O. We also report the synthesis and spectroscopic characterization of two rhodium(III) complexes of the general formula [Rh(1)Cl3(CH3OH)] (3) and [Rh(2)Cl3(CH3OH)] (4). The molecular structures of 3·2CH3OH and 4 were determined by single-crystal X-ray diffraction studies, revealing that these complexes adopt the mer-configuration. The solution stability of 3, 4 was studied by a combination of UV–Vis and 1H NMR spectroscopic techniques. All compounds were biologically evaluated for their anti- platelet activity using their potency to inhibit the action of PAF (Platelet-Activating Factor), which is an approach of continuous interest in the field. Complexes 3 and 4 were found to be potent PAF inhibitors with IC50 values in the micromolar range (1.0 μM and 3.9 μM respectively). Since PAF is the most potent inflammatory lipid mediator, the PAF-inhibitors and consequently the title compounds may be considered as potent examples in the search for novel anti-inflammatory drugs.
