- Sugar-Assisted Chirality Control of Tris(2,2'-bipyridine)-Metal Complexes
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2,2'-Bipyridine-4,4'-diboronic acid (2), a 2,2'-bipyridine derivative with sugar-binding sites was synthesized.The Δ vs.A chirality of the Fe2+*23 complex was selectively generated in correlation with the absolute configuration of added saccharides.
- Nakashima, Kazuaki,Shinkai, Seiji
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- The synthesis of diethyl 2-(2,2 ′ -bipyridin-4-ylmethylene)malonate and diethyl 3,3 ′ -(2,2 ′ -bipyridine-4,4 ′ -diyl)diacrylate
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Abstract: The new acrylic acid derivatives diethyl 2-(2,2′-bipyridin-4-ylmethylene)malonate and diethyl 3,3′-(2,2′-bipyridine-4,4′-diyl)diacrylate which may be used for the introduction of metal coordination sites in polyacrylates were synthesized and characterized. Intermediates of the syntheses were prepared by improved synthetic protocols working under microwave conditions whenever it was advantageous for the resulting product in terms of reaction time and/or chemical yield. In addition, the crystal structure of one of the intermediates, 4,4′-dibromo-2,2′-bipyridine (6), is reported, in which molecules are arranged into infinite chains by C-H—Br interactions. Graphical Abstract: SYNOPSIS Synthesis and characterization of new 2,2’-bipyridine ligands with substituents related to acrylic acid esters are reported. These compounds offer the possibility to incorporate 2,2’-bipyridine ligands or coordination compounds derived from them into polyacrylate materials. [Figure not available: see fulltext.].
- Heintz, Katharina,G?rls, Helmar,Imhof, Wolfgang
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- Varying the electronic structure of surface-bound ruthenium(II) polypyridyl complexes
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In the design of light-harvesting chromophores for use in dye-sensitized photoelectrosynthesis cells (DSPECs), surface binding to metal oxides in aqueous solutions is often inhibited by synthetic difficulties. We report here a systematic synthesis approach for preparing a family of Ru(II) polypyridyl complexes of the type [Ru(4,4′-R2-bpy)2(4,4′-(PO3H2)2-bpy)]2+ (4,4′(PO3H2)2-bpy = [2,2′-bipyridine]-4,4′-diylbis(phosphonic acid); 4,4′-R2-bpy = 4,4′-R2-2,2′-bipyridine; and R = OCH3, CH3, H, or Br). In this series, the nature of the 4,4′-R2-bpy ligand is modified through the incorporation of electron-donating (R = OCH3 or CH3) or electron-withdrawing (R = Br) functionalities to tune redox potentials and excited-state energies. Electrochemical measurements show that the ground-state potentials, E′(Ru3+/2+), vary from 1.08 to 1.45 V (vs NHE) when the complexes are immobilized on TiO2 electrodes in aqueous HClO4 (0.1 M) as a result of increased Ru dπ-π back-bonding caused by the lowering of the π orbitals on the 4,4′-R2-bpy ligand. The same ligand variations cause a negligible shift in the metal-to-ligand charge-transfer absorption energies. Emission energies decrease from max = 644 to 708 nm across the series. Excited-state redox potentials are derived from single-mode Franck-Condon analyses of room-temperature emission spectra and are discussed in the context of DSPEC applications.
- Ashford, Dennis L.,Brennaman, M. Kyle,Brown, Robert J.,Keinan, Shahar,Concepcion, Javier J.,Papanikolas, John M.,Templeton, Joseph L.,Meyer, Thomas J.
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- Long-Lived, Emissive Excited States in Direct and Amide-Linked Thienyl-Substituted RuII Complexes
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The excited state behavior of a new series of homoleptic and heteroleptic RuII complexes bearing thienyl groups appended to a 2,2′-bipyridine chelating ligand via direct, secondary and tertiary amide linkages is examined. The results of nanosecond transient absorption spectroscopy, emission lifetime measurements and bimolecular quenching experiments are correlated to determine that although the amide linkage does not act as a conjugated bridge to the peripheral substituents, it does not preclude possible electron transfer processes. Complexes bearing directly bound thienyl and bithienyl substituents exhibit long excited state and emission lifetimes (τem = 2 and 15 μs), with high emission quantum yields in solution (Φ = 0.35) and slow rates of non-radiative decay.
- Majewski, Marek B.,Smith, Jeremy G.,Wolf, Michael O.,Patrick, Brian O.
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p. 1470 - 1479
(2016/04/26)
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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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- ORGANIC METAL DYE, AND PHOTOELECTRIC ELEMENT AND DYE-SENSITIZED SOLAR CELL USING THE ORGANIC METAL DYE
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The present invention relates to an organic metal dye comprising fused heterocyclic derivatives, and to a photoelectric element and to a dye-sensitized solar cell using the organic metal dye.
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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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experimental part
p. 340 - 345
(2012/07/14)
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- A modular 'click' approach to substituted 2,2′-bipyridines
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The CuAAC reaction was used for the development of a click approach to a series of triazole-substituted bipyridinyl derivatives. 4,4′-Diethinyl 2,2′-bipyridine and 4,4′-diazido 2,2′-bipyridine were synthesized and tested in the cycloaddition reactions. While 4,4′-diazido 2,2′-bipyridine revealed unreactive in CuAAC reactions, its corresponding N,N′-dioxide afforded the expected cycloaddition product. Georg Thieme Verlag Stuttgart.
- Fabbrizzi, Pierangelo,Cecconi, Bianca,Cicchi, Stefano
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p. 223 - 226
(2011/03/22)
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- Electronic optimization of heteroleptic Ru(II) bipyridine complexes by remote substituents: Synthesis, characterization, and application to dye-sensitized solar cells
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We prepared a series of new heteroleptic ruthenium(II) complexes, Ru(NCS)2LL0 (3a-3e), where L is 4,40-di(hydroxycarbonyl)-2,20-bipyridine and L0 is 4,40-di(p-Xphenyl)- 2,20-pyridine (X = CN (a), F (b), H (c), OMe (d), and NMe2 (e)), in an attempt to explore the structure-activity relationships in their photophysical and electrochemical behavior and in their performance in dye-sensitized solar cells (DSSCs). When substituent X is changed from electron-donating NMe2 to electron-withdrawing CN, the absorption and emission maxima reveal systematic bathochromic shifts. The redox potentials of these dyes are also significantly influenced by X. The electronic properties of the dyes were theoretically analyzed using density functional theory calculations; the results show good correlations with the experimental results. The solar-cell performance of DSSCs based on dye-grafted nanocrystalline TiO2 using 3a-3e and standard N3 (bis[(4,40-carboxy-2,20-bipyridine)(thiocyanato)]ruthenium(II)) were compared, revealing substantial dependences on the dye structures, particularly on the remote substituent X. The 3d-based device showed the best performance: η = 8.30%, JSC = 16.0 mA 3 cm-2, VOC = 717 mV, and ff = 0.72. These values are better than N3-based device. 2011 American Chemical Society. 2011 American Chemical Society.
- Han, Won-Sik,Han, Jung-Kyu,Kim, Hyun-Young,Choi, Mi Jin,Kang, Yong-Soo,Pac, Chyongjin,Kang, Sang Ook
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p. 3271 - 3280
(2011/06/22)
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- Towards allosteric receptors - Synthesis of Resorcinarene-Functionalized 2,2′-Bipyridines and their metal complexes
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Based on a first: example of an allosteric hemicarcerand (1) we prepared four new 2,2′bipyridines that carry resorcinarene moieties in a highly convergent manner. Upon coordination to suitable transition metal ions or their complexes these compounds undergo conformational changes in a way that: they switch between "open" and. "closed" forms (2, 3, and 4) or vice versa (5), thus, bringing together or separating the two functional, moieties on the central, bipyridine, Among the transition metal complexes that act: as effectors for the conformational switching, [Re(CO)5Cl] and monomeric copper(I) complexes of sterically hindered 2,9-arylated 1,10-phenanthrolines proved, to be very effective.
- Staats, Holger,Eggers, Friederike,Hass, Oliver,Fahrenkrug, Frank,Matthey, Jens,Luening, Ulrich,Luetzen, Arne
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experimental part
p. 4777 - 4792
(2009/12/25)
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- Synthesis of 2,4-dibromopyridine and 4,4'-dibromo-2,2'-bipyridine. Efficient usage in selective bromine-substitution under palladium-catalysis
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We report an efficient method for preparing 2,4-dibromopyridine and 4,4'-dibromo-2,2'-bipyridine from the corresponding nitroazine N-oxide in one step via a tandem nucleophilic substitution-N-oxide reduction process. The one step preparation of 4,4'-dihalo-2,2'-bipyridines from dihalopyridines via a Stille reaction is also described. 4,4'-Dibromo-2,2'-bipyridine undergoes selective mono- or disubstitution processes under palladium catalysis. This short synthetic procedure is an efficient and reliable process for preparing conjugated pyridine and 2,2'-bipyridine building blocks for applications in coordination chemistry and materials science.
- Garcia-Lago, Ramon,Alonso-Gomez, Jose-Lorenzo,Sicre, Cristina,Cid, Maria-Magdalena
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- Divalent osmium complexes: Synthesis, characterization, strong red phosphorescence, and electrophosphorescence
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We report new divalent osmium complexes that feature strong red metal-to-ligand-charge-transfer (MLCT) phosphorescence and electrophosphorescence. The general formula of the complexes is Os(II)(N-N)2L-L, where N-N is either a bipyridine or a phenanthroline and L-L is either a phosphine or an arsine. New polypyridyl ligands synthesized are 4,4′-di(biphenyl)-2,2′-bipyridine (15) and 4,4′-di(diphenyl ether)-2,2′-bipyridine (16), and the 1,10-phenanthroline derivatives synthesized are 4,7-bis(p-methoxyphen-yl)-1,10-phenanthroline (17), 4,7-bis(p-bromophenyl)-1,10-phenanthroline (18), 4,7-bis(4′-phenoxybiphen-4-yl)-1,10-phenanthroline (19), and 4,7-bis(4-naphth-2-ylphenyl)-1,10-phenanthroline (20). 4,4′-Diphenyl-2,2′-bipyridine (21) and 4,7-diphenyl-1,10-phenanthroline (22) were also used in these studies. Strong π-acid ligands used were 1,2-bis(diphenylarseno) ethane (23), cis- 1,2-bis(diphenylphosphino)ethylene (24), and cis-1,2-vinylenebis(diphenylarsine) (25). Ligand 25 is used for the first time in these types of luminescent osmium complexes. These compounds feature strong MLCT absorption bands in the visible region and strong red phosphorescent emission ranging from 611 to 651 nm, with quantum efficiency up to 45% in ethanol solution at room temperature. Red organic light-emitting diodes (OLEDs) were successfully fabricated by doping the Os(II) complexes into blend of poly(N-vinylcarbazole) (PVK) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD). Brightness over 1400 cd/m2 for a double-layer device has been reached, with a turn-on voltage of 8 V. The maximum external quantum efficiency was 0.64%. Commission Internationale de I'Eclairage (CIE) chromaticity coordinates (x, y) of the red electrophosphorescence from the complexes are (0.65, 0.34), which indicates pure red emission.
- Carlson, Brenden,Phelan, Gregory D.,Kaminsky, Werner,Dalton, Larry,Jiang, Xuezhong,Liu, Sen,Jen, Alex K.-Y.
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p. 14162 - 14172
(2007/10/03)
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