- Sterically demanding methoxy and methyl groups in ruthenium complexes lead to enhanced quantum yields for blue light triggered photodissociation
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Ruthenium complexes containing a sterically congested metal center can serve as light activated prodrugs through photo-activated chemotherapy (PACT). In this work, we modified PACT agents containing 6,6′-dihydroxybipyridine (6,6′-dhbp) (Papish et al., Inorg. Chem., 2017, 56, 7519) by replacing it with a sterically bulky isoelectronic ligand, 6,6′-dimethoxybipyridine (6,6′-dmbp). The resulting complexes, [(phen)2Ru(6,6′-dmbp)]Cl2 (2OMe, phen = 1,10-phenanthroline) and [(dop)2Ru(6,6′-dmbp)]Cl2 (3OMe, dop = 2,3-dihydro-[1,4]dioxino[2,3-f][1,10]phenanthroline), have been fully characterized and display enhanced quantum yields for blue light triggered photodissociation of 0.024(6) and 0.0030(2), respectively. We have also synthesized 4OH = [(dmphen)2Ru(4,4′-dhbp)]Cl2 wherein dmphen = 2,9-dimethyl-1,10-phenanthroline and 4,4′-dhbp = 4,4′-dihydroxybipyridine. These ligands enhance steric bulk near the metal center and move the hydroxy groups further from the metal center, respectively. Complex 4OH displays a relatively low quantum yield of 0.0014(2). All of the new complexes (2OMe, 3OMe, 4OH) were tested in breast cancer cells (MDA-MB-231) and were non-toxic (IC50 > 100 μM). This has been interpreted in terms of unfavorable log(Do/w) values and furthermore photodissociation alone is insufficient for cytotoxicity. We also report the crystal structures of 4OH and 2OMe, the thermodynamic acidity of complex 4OH, and the redox potentials for all new complexes.
- Qu, Fengrui,Martinez, Kristina,Arcidiacono, Ashley M.,Park, Seungjo,Zeller, Matthias,Schmehl, Russell H.,Paul, Jared J.,Kim, Yonghyun,Papish, Elizabeth T.
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Read Online
- New ternary bipyridine-terpyridine copper(ii) complexes as self-activating chemical nucleases
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Seeking self-activating chemical nucleases with potential applications as therapeutic agents, new ternary terpyridine-bipyridine-Cu(ii) complexes carrying pendant cyclic amines were developed. After detailed characterization, the nuclease activity of the synthesized compounds was evaluated by using circular plasmid DNA as substrate and analyzing the products by agarose-gel electrophoresis. The new complexes present an impressive plasmid DNA cleaving ability, which triggers double-strand DNA breaks in the absence of any exogenous agents, via an oxidative mechanism. The binding affinity towards duplex DNA was determined using UV-Vis and fluorescence spectroscopic titrations. These studies showed that the tested complexes bind moderately (in the order of 104 M-1) to duplex DNA. The copper complexes displayed high cytotoxicity against ovarian carcinoma A2780 cells (4-fold cisplatin activity), surpassing the resistance on the cisplatin-resistant cell line (A2780cisR) with lower resistance factors. Cellular uptake studies showed that the ternary complexes were able to enter the cell with a significant localization in the cytoskeleton. This journal is
- Santos, Isabel,Gama, Sofia,Rodrigues, Ins,Marques, Fernanda,Palma, Elisa,Correia, Isabel,Carvalho, M. Fernanda N. N.,Pessoa, Joo Costa,Cruz, Andreia,Mendo, Snia,Santos, Isabel C.,Mendes, Filipa,Paulo, Antnio
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Read Online
- Electronic effects on reactivity and anticancer activity by half-sandwich N,N-chelated iridium(iii) complexes
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The synthesis and characterization of a series of organometallic half-sandwich N,N-chelated iridium(iii) complexes bearing a range of electron-donating and withdrawing substituents were described. The X-ray crystal structures of complexes 1, 3 and 5 have been determined. This work demonstrated how the aqueous chemistry, catalytic activity in converting coenzyme NADH to NAD+ and anticancer activity can be controlled and fine-tuned by the modification of the ligand electronic perturbations. In general, the introduction of an electron-withdrawing group (-Cl and-NO2) on the bipyridine ring resulted in increased anticancer activity, whereas an electron-donating group (-NH2,-OH and-OCH3) decreased the anticancer activity. Complex 6 bearing a strongly electron-withdrawing NO2 group displayed the highest anticancer activity (7.3 ± 1.2 μM), ca. three times as active as cisplatin in the A549 cell line. Notably, selective cytotoxicity for cancer cells over normal cells was observed for complexes 1 and 6. DNA binding does not seem to be the primary mechanism for cancer fighting. However, the aqueous chemistry, cell apoptosis and cell cycle, which show similar dependence on the ligand electronic perturbations as the anticancer activity, appear to together contribute to the anticancer potency of theses complexes. This work may provide an alternative strategy to enhance anticancer activity for these N,N-chelated organometallic half-sandwich iridium(iii) complexes.
- Guo, Lihua,Zhang, Hairong,Tian, Meng,Tian, Zhenzhen,Xu, Yanjian,Yang, Yuliang,Peng, Hongwei,Liu, Peng,Liu, Zhe
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supporting information
p. 16183 - 16192
(2018/10/04)
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- Synthesis method of 4,4'-dyhydroxyl-2,2'-dipyridyl
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The invention discloses a synthesis method of 4,4'-dyhydroxyl-2,2'-dipyridyl. The synthesis method comprises the following steps: (1) adding 2,2'-dipyridyl into a mixed solvent of an organic solvent and water for mixing, and adding dihydric phosphate and a surfactant for stirring at 30 to 35 DEG C for 20 to 35 minutes; (2) adding a mixture A of ferrate and sodium molybdate, feeding protective gas, heating the system to 50 to 60 DEG C, and enabling reaction for 5 to 8 hours; (3) cooling reaction fluid, and separating and purifying to obtain a product, namely 4,4'-dyhydroxyl-2,2'-dipyridyl. By the adoption of the synthesis method, the reaction steps are relatively short and are one-step reaction; the synthesis method is easy to operate, high in yield and low in process cost; furthermore, the post-treatment is simple, and less water pollution is caused.
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Paragraph 0016-0021
(2017/05/27)
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- NOVEL RUTHENIUM TYPE DYE AND PREPARATION THEREOF
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The present invention relates to a novel ruthenium-based dye and a producing method thereof and, more specifically, to a bipyridine-based ruthenium dye which prevents the interaction with I_2 of an electrolyte by introducing a hydrophobic group combined with oxygen into a ligand site, exhibits improved photoelectric conversion efficiency and long-term stability to greatly improve efficiency and lifespan of a solar cell, and is synthesized by a relatively simple method to reduce manufacturing costs. The bipyridine-based ruthenium dye of the present invention is used as a dye in a dye-sensitized solar cell (DSSC), and thus has higher efficiency and better long-term stability than existing dyes, thereby significantly improving efficiency of the solar cell.COPYRIGHT KIPO 2016
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Paragraph 0047; 0054; 0055; 0056; 0057; 0058
(2017/01/02)
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- Hydroxyl and amino functionalized cyclometalated Ir(III) complexes: Synthesis, characterization and cytotoxicity studies
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A series of Ir(III) complexes (?N)2Ir(N N) (N N are 4,4′-dihydroxy-2,2′-bipyridine and 4,4′-diamino-2,2′-bipyridine, and ?N are phenylpyridine, benzo[h]quinolone, and 2-phenylquinoline) were synthesized and characterized. Two of the complexes were structurally characterized via X-ray crystallography. The photophysical and photochemical properties of these complexes were studied. Preliminary studies of their applications on pH sensing, and cell imaging were also performed.
- Wu, Zhaozhen,Mu, Juanjuan,Wang, Qiong,Chen, Xing,Jensen, Lasse,Yi, Changqing,Li, Mei-Jin
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supporting information
p. 175 - 182
(2015/06/22)
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- Evaluation of Tris-Bipyridine Chromium Complexes for Flow Battery Applications: Impact of Bipyridine Ligand Structure on Solubility and Electrochemistry
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This report describes the design, synthesis, solubility, and electrochemistry of a series of tris-bipyridine chromium complexes that exhibit up to six reversible redox couples as well as solubilities approaching 1 M in acetonitrile. We have systematically modified both the ligand structure and the oxidation state of these complexes to gain insights into the factors that impact solubility and electrochemistry. The results provide a set of structure-solubility-electrochemistry relationships to guide the future development of electrolytes for nonaqueous flow batteries. In addition, we have identified a promising candidate from the series of chromium complexes for further electrochemical and battery assessment.
- Cabrera, Pablo J.,Yang, Xingyi,Suttil, James A.,Brooner, Rachel E. M.,Thompson, Levi T.,Sanford, Melanie S.
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p. 10214 - 10223
(2015/11/11)
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- COATED NANOPARTICLES
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The present invention relates to a method for preparing a composition comprising nanoparticles of a noble metal functionalised with at least one type of metal complex and surfactant. The method comprises providing a first solution comprising nanoparticles and surfactant, and a second solution comprising a first type of metal complex, and adding the second solution to the first solution. Each nanoparticle has a loading of at least 500 and the method permits independent control of particle size and loading and enables large particles with high loading to be reproduced without agglomeration.
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Paragraph 0039; 0040; 0041
(2014/08/07)
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- Aqueous reductive amination using a dendritic metal catalyst in a dialysis bag
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Water-soluble dendritic iridium catalysts were synthesized by attaching a reactive metal complex to DAB-Am dendrimers via an adapted asymmetric bipyridine ligand. These dendritic catalysts were applied in the aqueous reductive amination of valine while contained in a dialysis bag. Comparable conversions were observed as for the noncompartmentalized counterparts, albeit with somewhat longer reaction times. These results clearly show that the encapsulated catalyst system is suitable to successfully drive a complex reaction mixture with various equilibrium reactions to completion.
- Willemsen, Jorgen S.,Van Hest, Jan C.M.,Rutjes, Floris P.J.T.
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supporting information
p. 960 - 965
(2013/06/27)
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- Synthesis of phosphonic acid derivatized bipyridine ligands and their ruthenium complexes
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Water-stable, surface-bound chromophores, catalysts, and assemblies are an essential element in dye-sensitized photoelectrosynthesis cells for the generation of solar fuels by water splitting and CO2 reduction to CO, other oxygenates, or hydrocarbons. Phosphonic acid derivatives provide a basis for stable chemical binding on metal oxide surfaces. We report here the efficient synthesis of 4,4′-bis(diethylphosphonomethyl)-2,2′- bipyridine and 4,4′-bis(diethylphosphonate)-2,2′-bipyridine, as well as the mono-, bis-, and tris-substituted ruthenium complexes, [Ru(bpy) 2(Pbpy)]2+, [Ru(bpy)(Pbpy)2]2+, [Ru(Pbpy)3]2+, [Ru(bpy)2(CPbpy)]2+, [Ru(bpy)(CPbpy)2]2+, and [Ru(CPbpy)3] 2+ [bpy = 2,2′-bipyridine; Pbpy = 4,4′-bis(phosphonic acid)-2,2′-bipyridine; CPbpy = 4,4′-bis(methylphosphonic acid)-2,2′-bipyridine].
- Norris, Michael R.,Concepcion, Javier J.,Glasson, Christopher R. K.,Fang, Zhen,Lapides, Alexander M.,Ashford, Dennis L.,Templeton, Joseph L.,Meyer, Thomas J.
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p. 12492 - 12501
(2013/11/19)
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- Ruthenium(II) complex-based fluorescent sensor for peroxynitrite
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We have developed a new ruthenium complex, Ru(bpy)2[4-(2, 2′-bipyridin-4-yloxy)phenol]Cl2 (RuL), as a fluorescent sensor to detect peroxynitrite (ONOO-). The results showed that the addition of ONOO- to the aqueous solution of RuL would result in distinct fluorescence quenching at 600 nm. RuL exhibits a good selectivity for ONOO - over other reactive oxygen species (ROS) and reactive nitrite species (RNS), and the reaction time is less than 1.5 s. The sensing mechanism is proposed as the oxidative O-dealkylation reaction.
- Ma, Jingjin,Wu, Jiasheng,Liu, Weimin,Wang, Pengfei,Fan, Zhiyuan
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scheme or table
p. 340 - 345
(2012/07/14)
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- Synthetic Approaches to an Isostructural Series of Redox-Active, Metal Tris(bipyridine) Core Dendrimers
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Several types of six-armed, metal tris(bipyridine) core dendrimers were synthesized. Bis-4,4′-alkoxy bipyridine dendrons were prepared and employed to make tris(bipyridine) dendrimers. Although the ruthenium-centered and iron-centered dendrimers displayed
- Hong, Young-Rae,Gorman, Christopher B.
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p. 9019 - 9025
(2007/10/03)
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- Syntheses of Hydroxylated Bipyridines, III. - Synthesis of Unsymmetrically and Symmetrically Structured Dihydroxybipyridines
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Fifteen symmetrical and asymmetrical dimethoxybipyridines and the pertinent diols are prepared and characterized.Reductive cross coupling of halopyridines with Ni(0) may result in complex mixtures.The same is true for an alternative reaction of (trimethylstannyl)pyridines with halopyridines in the presence of Pd(0).UV, 1H-, and 13C-NMR spectra of the bipyridine derivatives are tabulated.Key Words: Bipyridinediols / Pyridines / Stannylpyridines
- Dehmlow, Eckehard V.,Sleegers, Arthur
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p. 953 - 960
(2007/10/02)
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