- An Active-Site Sulfonate Group Creates a Fast Water Oxidation Electrocatalyst That Exhibits High Activity in Acid
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The storage of solar energy in chemical bonds will depend on pH-universal catalysts that are not only impervious to acid, but actually thrive in it. Whereas other homogeneous water oxidation catalysts are less active in acid, we report a catalyst that maintained high electrocatalytic turnover frequency at pH values as low as 1.1 and 0.43 (kcat=1501±608 s?1 and 831±254 s?1, respectively). Moreover, current densities, related to catalytic reaction rates, ranged from 15 to 50 mA cm?2 mM?1 comparable to those reported for state-of-the-art heterogeneous catalysts and 30 to 100 times greater than those measured for two prominent literature homogeneous catalysts at pH 1.1 and 0.43. The catalyst also exhibited excellent durability when a chemical oxidant was used (CeIV, 7400 turnovers, TOF 0.88 s?1). Preliminary computational studies suggest that the unusual active-site sulfonate group acts a proton relay even in strong acid, as intended.
- Nash, Aaron G.,Breyer, Colton J.,Vincenzini, Brett D.,Elliott, Gregory I.,Niklas, Jens,Poluektov, Oleg G.,Rheingold, Arnold L.,Smith, Diane K.,Musaev, Djamaladdin G.,Grotjahn, Douglas B.
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p. 1540 - 1545
(2020/12/01)
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- Luminescent complexes of europium (III) with 2-(phenylethynyl)-1,10-phenanthroline: The role of the counterions
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New antenna ligand, 2-(phenylethynyl)-1,10-phenanthroline (PEP), and its luminescent Eu(III) complexes, Eu(PEP)2Cl3 and Eu(PEP)2(NO3)3, are synthesized and characterized. The syn-thetic procedure applied is based on reacting of europium salts with ligand
- Dimitrova, Yana,Dimov, Deyan,Elenkova, Denitsa,Lyapchev, Rumen,Morgenstern, Bernd,Romanova, Julia,Tsvetkov, Martin,Zaharieva, Joana
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- Synthesis of Novel Chiral Phenanthroline Ligands and a Copper Complex
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A novel class of chiral multidentate ligands has been designed and synthesized from the important classic ligand 1,10-phenanthroline and amino acids. The ligands were proven to be able to coordinate with copper(2+) ion by the formation of a novel chiral c
- Li, Jian,Tang, Jingjing,Yang, Xueyan,Zhang, Zhipeng
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- Copper-Catalyzed Regioselective C-H Amination of Phenol Derivatives with Assistance of Phenanthroline-Based Bidentate Auxiliary
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A copper-catalyzed regioselective direct amination of phenol derivatives with diarylamines via phenanthroline-based bidentate auxiliary-directed C-H cleavage has been developed. This reaction proceeds smoothly with only a copper salt and air as a terminal oxidant to produce the corresponding o-aminophenols in good yields. Moreover, the directing group can be easily attached, detached, and recycled. Additionally, preliminary computational studies of the reaction with DFT have also been performed.
- Takamatsu, Kazutaka,Hayashi, Yoshihiro,Kawauchi, Susumu,Hirano, Koji,Miura, Masahiro
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p. 5336 - 5344
(2019/06/13)
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- NNB-type tridentate boryl ligands enabling a highly active iridium catalyst for C–H borylation
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Boryl ligands play a very important role in catalysis because of their very high electron-donating property. In this paper, NNB-type boryl anions were designed as tridentate ligands to promote aryl C–H borylation. In combination with [IrCl(COD)]2/su
- Ding, Siyi,Wang, Linghua,Miao, Zongcheng,Li, Pengfei
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- With the antibacterial activity of the substituted 2 - amido - 1, 10 - eurepium (by machine translation)
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The invention relates to a compound of formula I is shown of a substituted 2 - amido - 1, 10 - eurepium antibacterial compound or its physiologically acceptable salt and their method of preparation, also relates to a pharmaceutical composition comprising said compound. Wherein each substituent defined as stated in claims. (by machine translation)
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- Bio-inspired Herringbone Foldamers: Strategy for Changing the Structure of Helices
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Cyclic oligomers of azole peptides were isolated from a multitude of marine organisms and were used for a large number of molecular machines. As shown previously, oligomers derived from achiral imidazole amino acids fold into canonical helices. Here we show that a minor change, the introduction of a methyl group in the δ position, results in a significant change in the secondary structure of the corresponding oligomers. Instead of a canonical helix, a noncanonical herringbone helix is formed. In the latter, the slope along the helix changes its sign at least twice per turn. This strategy allows a remarkable change of the secondary structure via a small modification. By means of enantiomerically pure amino acids, we were able to control, for the first time, both the helicity of the helix and the form of the herringbone. The investigation of the underlying herringbone basic element and its folding to a noncanonical helix were conducted by NMR and CD spectroscopy, as well as by X-ray crystallography and quantum chemical calculations.
- Adam, Abdulselam,Haberhauer, Gebhard,W?lper, Christoph
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p. 4203 - 4215
(2017/04/28)
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- A Fluorine-18 Radiolabeling Method Enabled by Rhenium(I) Complexation Circumvents the Requirement of Anhydrous Conditions
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Azeotropic distillation is typically required to achieve fluorine-18 radiolabeling during the production of positron emission tomography (PET) imaging agents. However, this time-consuming process also limits fluorine-18 incorporation, due to radioactive decay of the isotope and its adsorption to the drying vessel. In addressing these limitations, the fluorine-18 radiolabeling of one model rhenium(I) complex is reported here, which is significantly improved under conditions that do not require azeotropic drying. This work could open a route towards the investigation of a simplified metal-mediated late-stage radiofluorination method, which would expand upon the accessibility of new PET and PET-optical probes.
- Klenner, Mitchell A.,Pascali, Giancarlo,Zhang, Bo,Sia, Tiffany R.,Spare, Lawson K.,Krause-Heuer, Anwen M.,Aldrich-Wright, Janice R.,Greguric, Ivan,Guastella, Adam J.,Massi, Massimiliano,Fraser, Benjamin H.
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p. 6499 - 6503
(2017/05/15)
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- A highly practical and convenient halogenation of fused heterocyclic N-oxides
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A novel, simple and practical method for the regioselective halogenation of fused heterocyclic N-oxides has been developed. It employs Vilsmeier reagent, generated in situ by POX3and DMF, as both the activating agent and the nucleophilic halide source. The method is amenable across a broad range of substrates, including quinolines, isoquinolines and the diazine N-oxides, possessing a variety of substitution patterns. Furthermore, all of the reagents associated are cheap and easy to obtain. The potential extension of this method to a one-pot oxidation/halogenation sequence that obviates the need for isolation of the N-oxide intermediates is also presented.
- Wang, Dong,Wang, Yuxi,Zhao, Junjie,Li, Linna,Miao, Longfei,Wang, Dong,Sun, Hua,Yu, Peng
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p. 5762 - 5768
(2016/08/30)
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- Substituted phenanthrolines as antennae in luminescent EuIII complexes
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Eight novel europium(III)-based coordination compounds with 1,10-phenanthroline (phen) ligands with a chloro, methoxy, ethoxy, cyano, carboxylic acid, methyl carboxylate, ethyl carboxylate, and amino substituent on the 2-position have been prepared in yields ranging from 43 to 89 %. Additionally, one lanthanum(III) coordination compound of 2-amino-1,10- phenanthroline has been isolated. All compounds have the general formula [Ln(L)2(NO3)3], except for the compound with the carboxylate ligand, which has the formula [Eu(O2Cphen) 3]. Three of the EuIII complexes as well as the La III compound crystal structures have been determined, all of which show similar N4O6 coordination spheres for the Ln III ion. Seven compounds exhibit bright luminescence that is characteristic of EuIII upon irradiation with near-UV radiation, thus indicating efficient ligand-to-metal energy transfer. The complex with 2-amino-1,10-phenanthroline is nonluminescent. The solid-state photoluminescent quantum yields range from 10 to 79 %, and the luminescence lifetimes vary from 0.43 to 1.57 ms. Analysis of the spectral intensities with the Judd-Ofelt theory shows a significant contribution of nonradiative processes that quench the luminescence of the 5D0 level on EuIII. Eight new EuIII complexes with 1,10-phenanthroline ligands substituted on the 2-position have been prepared, analyzed, and the photoluminescence properties studied. The complex with the 2-chloro substituent exhibits bright photoluminescence with a high quantum yield of 78 %. The complex with the 2-amino substituent is nonluminescent. Copyright
- Akerboom, Sebastiaan,Van Den Elshout, Jos J. M. H.,Mutikainen, Ilpo,Siegler, Maxime A.,Fu, Wen Tian,Bouwman, Elisabeth
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p. 6137 - 6146
(2014/01/06)
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- RARE EARTH METAL COMPLEX HAVING PHENANTHROLINE COMPOUND AS LIGAND
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The present invention provides a rare earth metal complex represented by the following formula (I).
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- PHENANTHROLINE DERIVATIVES AND THEIR USE AS LIGANDS
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The present invention provides a novel compound having a phenanthroline structure represented by the following formula (I) or a salt thereof useful as a ligand of an analytical marker using fluorescence.
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- OLED DEVICE EMPLOYING ALKALI METAL CLUSTER COMPOUNDS
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The invention provides an OLED device containing certain alkali metal cluster compounds with mixed ligands, such compounds, and methods of making them. In particular, the cluster compound is a neutrally charged mixed cluster compound comprising first and second subunits with the first subunit comprising an alkali metal salt of a nitrogen containing a heterocyclic ligand bearing a anionic hydroxy group and the second subunit consisting of an organic alkali metal salt different than the first subunit.
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- Concave 1,10-phenanthrolines as ligands for cyclopropanations - Towards a deeper understanding of the stereoselectivity
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Four new mono- and bimacrocyclic 1,10-phenanthrolines - 3b and 4a-c - containing aryl bridgeheads have been synthe- sised. The etherification of the aryl bridgeheads was accomplished by Williamson or Mitsunobu reactions. A key step in the synthesis of the macrocyclic phenanthrolines 3 and 4 is the Suzuki coupling of 2,9-diiodo-1,10-phenan- throline (12) with the appropriately substituted boronic acids 17 and 20. Ring-closing metathesis and hydrogenation completed the synthesis. The resulting macrocyclic 1,10-phenan- throlines 3b and 4a-c were tested as ligands in a copper(I)- catalysed stereoselective cyclopropanation.
- Eggers, Friederike,Luening, Ulrich
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scheme or table
p. 2328 - 2341
(2009/09/05)
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- Phenanthroline-derived ratiometric chemosensor for ureas
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The syntheses of 1,10-phenanthroline fluorophore-based chemosensor 7 and its truncated analog 9 are reported. Interactions of these compounds with urea, thiourea, 1,3-dimethylurea, tetrahydropyrimidin-2(lH)-one, imidazolidin-2-one, and selected uronium sa
- Engel, Yoni,Dahan, Adi,Rozenshine-Kemelmakher, Emily,Gozin, Michael
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p. 2318 - 2328
(2007/10/03)
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- Spectroscopic and Electrochemical Characterisation of some Complexes with Azamacrocycle Ligands
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This work describes the synthesis and infrared, uv-visible, 1H nmr and electrochemical characterisation of azacyclophanes and naphthalocyanines ligands and some NiII CuII, CoII and ZnII complexes.The characterisation of some non commercial precursors of these compounds is also informed.The results show that the ligands and complexes are essentially planar, their optical properties are similar to those found in phthalocyanines and some ligands stabilises NiI or CuI at potentials less than 1 V vs ESC.In order to increase the solubility of these systems in polar solvents, some alternatives to sulphonation are proposed.
- Costamagna, J.,Canales, J.,Vargas, J.,Alvarado, A.,Ferraudi, G.
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p. 877 - 884
(2007/10/02)
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- Chemistry of Polydentate Ligands. Part 5. Complexes of 2,9-Dihydrazino-derivatives of 1,10-Phenanthroline. Dependence of Coordination Number of a Ligand on the Anion present
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Two quadridentate ligands have been prepared by rection of 2,9-dichloro-1,10-phenantroline with hydrazine hydrate and methylhydrazine.The formation of complexes of AgI, FII, MnII, ZnII, CdII, HgII, and NiII with these ligands is described.Electrical conductivity, i.r., and 1H n.m.r. spectral data of diamagnetic complexes are reported.The compound 2,9-dihydrazino-1,10-phenantroline can also act as a tridentate ligand, as in the complexes with nickel perchlorate, where the metal to ligand ratio is 1 : 2.Electronic spectral data of the nickel(II) complexes are presented.The preparation of a tridentate ligand, 2-(1-methylhydrazino)-1,10-phenantroline, and of nickel(II) and iron(II) complexes of this ligand is also reported.
- Lewis, Jack,O'Donoghue, Timothy D.
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p. 736 - 742
(2007/10/02)
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