- Synthesis and Electrochemical Properties of 2-(4-R1-Phenyl)-6-(4-R2-phenyl)-4-phenyl-3,4-dihydro1,2,4,5-tetrazin-1(2H)-yls
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Abstract: A new methodology for creating electroactive components for organic batteries,based on the construction of a molecular platform including stable3,4-dihydro-1,2,4,5-tetrazin-1(2H)-ylradicals was described. A series of2-(4-R1-phenyl)-6-(4-R2-phenyl)-4-phenyl-3,4-dihydro-1,2,4,5-tetrazin-1(2H)-yls with substituents of various nature wasobtained. It was shown that the substituents R1 inthe aromatic ring at position 2 of the tetrazinyl fragment influence the valueof the oxidation potential in the radical, but do not influence the value of thereduction potentials, while the substituent R2 of thearomatic ring at position 6 influence the values of the reduction potentials andpractically do not influence oxidation potential values. Based on the obtainedelectrochemical data, a correlation structure–potential value was revealed forthe cathodic and anodic process, with the help of which triarylsubstituted3,4-dihydro-1,2,4,5-tetrazin-1(2H)-ylradicals with high values of the electrochemical gap were obtained.
- Akhmatova, A. A.,Balandina, A. V.,Chernyaeva, O. Yu.,Kostryukov, S. G.,Kozlov, A. Sh.,Kraynov, E. V.,Lukshina, Yu. I.,Pryanichnikova, M. K.
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p. 341 - 351
(2020/04/27)
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- Microwave mediated solvent free synthesis of formazans catalyzed by simple ionic liquids derived from dialkylammonium salts
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A microwave mediated, ionic liquid catalyzed, VOC free and one pot synthesis of formazans was developed. In an alternative procedure, resin immobilized diazonium ions was used as a solid supported reaction for formazan synthesis. The efficiency of both the procedures was examined with respect to yield of product, reduction of reaction time and environmental impact. Products were obtained in a short reaction time and in moderate to high yield. This study was undertaken to find an alternative green protocol for the synthesis of formazans using ionic liquid as catalyst in aqueous media in the absence of corrosive mineral acids, buffered solutions and VOCs.
- Das, Pranab Jyoti,Begum, Jesmin
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p. 44604 - 44609
(2015/06/02)
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- BF3-functionalized silica-coated magnetic nanoparticles as a novel heterogeneous solid acid for synthesis of formazan derivatives via a green protocol
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A new type of green heterogeneous solid acid was prepared by the immobilization of BF3·Et2O on the surface of Fe3O4@SiO2 core-shell nanocomposite (Fe3O4@SiO2-BF3) and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDS), and transmission electron microscope (TEM). The activity of this super solid acid was probed through the synthesis of aryl diazonium salts as the starting reactant and then, their diazo coupling with aldehyde phenylhydrazones for formation of formazan derivatives in a solvent-free medium at room temperature. This clean and environmentally benign methodology has advantages such as: no need for corrosive and toxic liquid acids, solvents, or buffer solutions, room temperature reaction, high yields, and short reaction times. In addition, long-term stability of aryl diazonium salts supported on the surface of Fe3O4@SiO2-BF3 magnetic nanoparticles (MNPs) at room temperature was one of the most important results of this procedure.
- Bamoniri, Abdolhamid,Moshtael-Arani, Naimeh
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p. 662 - 672
(2015/06/25)
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- Nano BF3·SiO2: A green heterogeneous solid acid for synthesis of formazan dyes under solvent-free condition
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A solvent-free, efficient and rapid approach for synthesis of formazan dyes was developed by diazotization of aromatic amines with NaNO2, nano silica-supported boron trifluoride (nano BF3·SiO2), then diazo coupling with aldehyde phenylhydrazones by grinding method at room temperature. This study aimed to overcome the limitations and drawbacks of the previous reported methods such as: low temperature, using corrosive and toxic acids and solvents, using buffer solutions, instability of aryl diazonium salts, modest yields, and long reaction times.
- Bamoniri, Abdolhamid,Mirjalili, Bi Bi Fatemeh,Moshtael-Arani, Naimeh
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p. 272 - 278
(2014/07/22)
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- Arylations mediated by lead(IV) in the presence of formazan and imine ligands
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The use of formazan and imine ligands in arylations of β-dicarbonyl systems by phenyl boronic acid/lead(IV) carboxylates is examined.
- Iqbal, Amjid,Moloney, Mark G.,Siddiqui, Hamid Latif,Thompson, Amber L.
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scheme or table
p. 4523 - 4525
(2009/12/03)
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- Electrochemical studies of verdazyl radicals
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(Chemical Equation Presented) The redox properties of verdazyl radicals are presented using cyclic voltammetry techniques. These radicals can be reversibly reduced as well as oxidized. Electron-donating and -withdrawing substituents have significant effects on the oxidation and reduction potentials as well as the cell potential (Ecell = |Eox° - E red°|) for these radicals; a correlation between the electron spin distribution and redox properties is developed.
- Gilroy, Joe B.,McKinnon, Stephen D. J.,Koivisto, Bryan D.,Hicks, Robin G.
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p. 4837 - 4840
(2008/03/18)
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- Formazans as β-diketiminate analogues. Structural characterization of boratatetrazines and their reduction to borataverdazyl radical anions
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Formazans react with boron triacetate to produce boratatetrazines, which can be reduced to yield borataverdazyl radical anions - the first boron containing verdazyl radicals. The Royal Society of Chemistry.
- Gilroy, Joe B.,Ferguson, Michael J.,McDonald, Robert,Patrick, Brian O.,Hicks, Robin G.
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p. 126 - 128
(2007/10/03)
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- Syntheses of formazans under phase-transfer conditions
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Several 1,3,5-triarylformazans were synthesized (42-77%) using a new methodology. Azo-coupling of aryldiazonium salts with arylaldehyde arylhydrazones under mild basic conditions in two-phase liquid-liquid media is efficiently promoted by phase-transfer catalysts (onium salts or dicyclohexano-18-crown-6) at 5-25°C. The condensation of benzaldehyde with phenylhydrazine followed by phase-transfer catalyzed azo-coupling with phenyldiazonium chloride (one-pot procedure) gave 1,3,5-triphenylformazan in a 54% yield without isolation of the intermediate benzaldehyde phenylhydrazone. A double azo-coupling reaction of phenyldiazonium chloride with 9 different CH-active compounds afforded corresponding formazan only in the case of phenylpyruvic acid. Reaction in malonamide gave 3-carbamoyl-1,5-diphenylformazan instead of the expected 1,5-diphenylformazan.
- Katritzky,Belyakov,Cheng,Durst
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p. 577 - 581
(2007/10/02)
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- Kinetics and Mechanism of Oxidative Cyclization of Formazans to Tetrazolium Salts by Thallium(III) Acetate
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The kinetics of thallium(III) acetate oxidation of 1,3,5-triarylformazans have been investigated in acetic acid-water mixture.The reaction, which leads to tetrazolium salt as the product, follows the rate-law .The effect of substituent in the aldehyde (3-phenyl), the phenylhydrazine (l-phenyl) and the aryldiazonium (5-phenyl) moieties on the reaction rate has been studied and the corresponding Hammett rhos are -0.78, -0.85 and -0.8 respectively.A mechanism for the oxidative cyclization is proposed involving the formation of a N-thallated complex between the formazan and T1 (III) acetate which decomposes in a slow step accompanied by a ring closure between N-1 and N-5.
- Balakrishnan, R.,Srinivasan, V. S.,Venkatasubramanian, N.
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p. 404 - 406
(2007/10/02)
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