- Unusual Stabilities of 6,6'-Bis(aminomethyl)-2,2'-bipyridyl Chelates of Transition-metal Ions and Crystal Structures of the Ligand and its Copper(II) and Nickel(II) Complexes
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An improved four-step synthesis of the tetradentate compound 6,6'-bis(aminomethyl)-2,2'-bipyridyl (badp) has been developed and the crystal structure of its dihydrochloride monohydrate determined: space group C2/c, a = 11.991(2), b = 5.703(1), c = 22.109(3) Angstroem, β = 97.17(1) deg and Z = 4.The complexes of copper(II) and nickel(II) with badp have also been synthesized and structurally characterized.The metal ion in Br2 is five-co-ordinated and the complex crystallizes in the monoclinic P21/c space group with a = 11.508(3), b = 9.584(3), c = 14.362(30 Angstroem, β = 107.93(2) deg and Z = 4.The complex Br contains six-co-ordinated Ni(II) and crystallizes in the monoclinic P21/c space group with a = 11.387(3), b = 9.417(2), c = 14.317(5) Angstroem, β = 106.21(2) deg and Z = 4.The stepwise stability constants of the 1 : 1 ligand to metal complexes of badp with divalent transition-metal ions have been determined in KCl as supporting electrolyte (0.100 mol dm-3) at 25.0 deg C: log KML = / for the Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes is 8.94, 10.16, 11.87, 15.05 and 10.02 respectively.Iron(II) and cobalt(II) also formed 2 : 1 complexes with badp.The unusually low stabilities of the transition-metal complexes are considered due to the low basicity of the ligand and to the unfavourable spacing of its donor groups as indicated by the structures of the complexes of Ni(II) and Cu(II).
- Wang, Zheng,Reibenspies, Joseph,Motekaitis, Ramunas J.,Martell, Arthur E.
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- Improved Halogenation of Methyl Aromatics and Methyl Heteroaromatics: Unexpected Reactivity of Tetrahalogeno-diphenylglycolurils
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1,3,4,6-Tetrachloro (TCDGU) and 1,3,4,6-tetrabromo-3α,6α-diphenylglycolurils smooth halogen oxidizers have been exploited in a new direction as reagents for free radical substitution toward some N-halosuccinimide nonreactive bis-heterocycles. An unexpected selectivity and reactivity were observed with methyl benzenes, methyl heterocycles, and methyl-bis-heterocycles of interest. A chemometric study has been performed to optimize five independent factors of the chlorination reaction with TCDGU. The predictive model was established either for the halogenation conversion and the ratio of monochlorination.
- Moretti, Florian,Poisson, Guillaume,Marsura, Alain
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p. 173 - 183
(2016/05/19)
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- Template synthesis, characterization, and antimicrobial activity of a new lead (II) Schiff base complex
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A novel lead (II) complex of Schiff base containing three bipyridine units was synthesized by the template reaction between a new amine compound, 6-methyl-6′-(2-aminophenoxymethyl)-2,2′-bipyridine, and 2,2′-bipyridine-6,6′-dicarboxaldehyde in the presence of a Pb(II) perchlorate ion. The new amino compound and Schiff base complex, [PbL](ClO4)2·2H2O, were characterized by using matrix-assisted laser desorption/ionization with time-of-flight mass spectroscopy, FAR FT-IR, UV/visible spectroscopy, 1H NMR, elemental analyses (CHN), and molar conductivity measurements. Then the synthesized complex was screened in vitro for its antibacterial and antifungal activities against three Gram-negative and two Gram-positive bacteria and also against Candida albicans as a fungus by the microdilution broth method as a minimal inhibitory concentration. [PbL](ClO4)2·2H2O exhibits moderate activity on Staphylococcus aureus and Listeria monocytogenes when compared with standard drug and also shows moderate antifungal activity on the fungus Candida albicans.
- Beynek, Nesrin,Tan, Nurcihan,Beynek, Hayrettin
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p. 145 - 150
(2015/12/09)
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- Synthesis and characterization of new binaphthyl-linked phenanthroline-, bipyridine-, or pyridine-derived ligands, and the study of their cytotoxic activity
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In the present work, we describe the synthesis and characterization of five new versatile acyclic or macrocyclic ligands containing binaphthyl-linked pyridine, bipyridine, or phenanthroline groups in their framework (see Schemes 1-4). The structures of the ligands were elucidated on the basis of elemental analyses, IR, 1H-NMR, 13C-NMR, and FAB mass spectra. The cytotoxicity of these compounds was tested in vitro by using the tetrazolium salt reduction (MTT) assay on A549 (human lung carcinoma epithelial like) cells. All of the tested compounds induced time- and concentration-dependent cytotoxic effect.
- Beynek, Nesrin,Ulucam, Gueherguel,Benkli, Kadriye,Koparal, Ayse Tansu
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scheme or table
p. 2089 - 2096
(2009/02/08)
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- Enantioselektive Synthese von Helicaten auf Bipyridin-Kupfer(I)-Basis durch den Templateffekt eines chiralen Sekundaerstrukturelements: Uebertragung von stereochemischer Information im Nanometerbereich
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Keywords: Chiralitaet; Helices; Kupferverbindungen; Selbstorganisation
- Woods, Craig R.,Benaglia, Maurizio,Cozzi, Franco,Siegel, Jay S.
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p. 1977 - 1980
(2007/10/03)
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- Photoactive Cryptands Synthesis of the Sodium Cryptates of Macrobicyclic Ligands Containing Bipyridine and Phenanthroline Groups
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The NaBr cryptates of five macrobicyclic ligands containing bipyridine (bpy) and phenanthroline (phen) groups, i.e. of 1 2 3 4 and 5, have been prepared. 1, 2, 4 and 5 have been obtained in high yield by condensation of bis(bromomethyl)bipyridine 6 or -phenanthroline 9 with the corresponding macrocyclic diamines in presence of Na2CO3.Direct access to the NaBr complexes of the symmetrical cryptands 1 and 3 was achieved by a one-step macrobicyclisation procedure.The metal-ion complexes of ligands 1-5 have the attractive feature of combining the cation inclusion nature of cryptates with the photoactivity of bipyridine and phenanthroline groups; they may thus be expected to possess a variety of interesting physical and chemical properties.
- Rodriguez-Ubis, Juan-Carlos,Alpha, Beatrice,Plancherel, Dominique,Lehn, Jean-Marie
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p. 2264 - 2269
(2007/10/02)
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