- An investigation on the impact of halidization on substituted dimethoxybenzenes
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Functionalized organic molecules are emerging as charge storage materials in electrochemical technologies as the breadth and diversity of the organic design space offers the possibility of purpose-built materials with property sets optimized for a particular application. First developed as overcharge protection materials in lithium-ion batteries, substituted dialkoxybenzenes represent a potentially promising molecular platform for advancing soluble charge storage materials. Here, we systematically substitute a series of halide groups at the 2- and 5-positions of the 1,4-dimethoxybenzene core, investigate the impact the halide groups have on molecular properties using electrochemical and spectroscopy methods, and compare these results to those of 2,5-dimethyl-1,4-dimethoxybenzene (25DDB), a previously reported derivative. In general, we observe that introduction of heavy halogen atoms leads to decreased gravimetric capacity as compared to 25DDB, but concomitantly improves solubility and redox potentials. As the halide functional group increases in size, the active material becomes less stable in its oxidized state as evinced by both cyclic voltammetry and bulk electrolysis cycling. None of the halogenated species are as stable as 25DDB indicating that these materials may be better suited for applications with more rapid cycling conditions (e.g., redox shuttling). More broadly, these results may serve as a useful data set for computational methods for materials discovery and optimization.
- Brushett, Fikile R.,Carney, Thomas J.,Huang, Jinhua,Kowalski, Jeffrey A.,Zhang, Lu
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- One-Pot Synthesis to Quinone-Based Diaza[3.3]cyclophanes
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A simple one-pot synthesis to [3.3]cyclophanes that involves quinone moieties was found. The protocol tolerates a variety of amines that include aliphatic and aromatic structures with different functional groups, such as hydroxy groups, amides, and terminal double and triple bonds. The straightforward synthesis can be performed by a twofold N-alkylation reaction with 2,5-bis(bromomethyl)-3,6-dimethyl-1,4-benzoquinone (1). Neither anhydrous nor inert conditions are required. Various amines can be employed without any activating groups, several functionalities at end groups are tolerated, and the cyclophanes generated can be easily modified or embedded into larger molecular architectures. The redox-active nature of these cyclophanes allows their use in electron-transfer processes.
- Stahlhofen, Jana Marie,Schollmeyer, Dieter,Waldvogel, Siegfried R.
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p. 7226 - 7230
(2017/10/18)
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- Charge-transfer complex formations of tetracyanoquinone (cyanil) and aromatic electron donors
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Single-electron oxidants are the primary reagents for investigations of the new oxidants and the development of electron-accepting materials for application in optoelectronics. Quinones are the well-known class of the neutral single-electron oxidants. Here, we present the properties of the strongest neutral electron acceptor of this class tetracyanoquinone (cyanil) and investigate its electron-accepting strength by analyzing the charge-transfer complex formations with the aromatic donor molecules. Charge-transfer complexes of tetracyanoquinone with aromatic electron donors are characterized spectroscopically in solution and isolated as the single crystals.
- Jalilov, Almaz S.,Lu, Jianjiang,Kochi, Jay K.
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- C-D-glucopyranosyl derivatives of tocopherols - Synthesis and evaluation as amphiphilic antioxidants
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Treatment of dimethylhydroquinone dimethyl ethers (ortho and meta isomers) with glycopyranose pentaacetates (D-gluco, D-galacto) in the presence of SnCl4 and F3CCO2Ag selectively afforded the corresponding C-β-D-glycosyl derivatives by aromatic electrophilic substitution. Oxidation of the dimethoxybenzene moiety with ceric ammonium nitrate delivered C-β-D-glycosyl-dimethylbenzoquinones, which were reduced with Na2S2O4 to the corresponding C-β-D-glycosyldimethylhydroquinones. ZnCl2-catalyzed cyclization either with methylbut-2-en-1-ol (prenyl alcohol) or with all-racemic phytol led to acetyl-protected C-β-D-glycosyl chromanols or C-β-D-glycosyl tocopherols, the sugar residues of which were deacetylated under base catalysis conditions. These new molecules were evaluated as antioxidants in terms of their ability to inhibit the peroxidation of linoleic acid in SDS micelles. The position of the C-glucosyl moiety on the phenolic nucleus emerges as the critical structural determinant of their activity. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- He, Li,Galland, Stephanie,Dufour, Claire,Chen, Guo-Rong,Dangles, Olivier,Fenet, Bernard,Praly, Jean-Pierre
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experimental part
p. 1869 - 1883
(2009/04/04)
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- TRICYCLIC DIHYDROBENZOFURAN DERIVATIVES, PROCESS FOR THE PREPARATION THEREOF AND AGENTS
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A compound represented by the formula: wherein Ring A is a non-aromatic 5- to 7-membered nitrogen-containing heterocyclic ring which may be further substituted, Ring B is benzene ring which is further substituted, Ring C is a dihydrofuran ring which may b
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- Synthesis of quinones from hydroquinone dimethyl ethers. Oxidative demethylation with cobalt(III) fluoride
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The oxidative demethylation of 1,4-dimethoxynaphthalene and 1,4- dimethoxybenzene derivatives with cobalt(III) fluoride proceeded in good to excellent yield to afford the corresponding naphthoquinone and benzoquinone derivatives.
- Tomatsu, Ayumi,Takemura, Syunji,Hashimoto, Kimiko,Nakata, Masaya
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p. 1474 - 1476
(2007/10/03)
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- Selective nitration versus oxidative dealkylation of hydroquinone ethers with nitrogen dioxide
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Various alkyl-substituted p-dialkoxybenzenes (ArH) react readily with nitrogen dioxide (NO2) in dichloromethane solution via either nitration (ArNO2) or oxidative dealkylation to quinones (Q). Spectral transients indicate that these coupled processes proceed from the dialkoxybenzene radical cation (ArH+) formed as the common reactive intermediate from electron-transfer in the disproportionated precursor [ArH, NO+]NO3-. In fast subsequent steps, ArH+ undergoes homolytic coupling with NO2 (which leads to aromatic nitration) and nucleophilic attack of NO3- (which results in oxidative dealkylation). As such, the competition between nitration and oxidative dealkylation is effectively modulated by solvent polarity and added nitrate.
- Rathore,Bosch,Kochi
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p. 6727 - 6758
(2007/10/02)
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- SUBSTITUTED 7,7',8,8'-TETRACYANOQUINODIMETHANES. I. METHODS OF SYNTHESIS OF SUBSTITUTED 7,7',8,8'-TETRACYANOQUINODIMETHANES
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The synthesis of 2-methyl-, 2,5-dimethyl-, and 2-isopropyl-7,7'-8,8'-tetracyanoquinodimethanes was realized from 2-methyl-, 2,5-dimethyl-, and 2-isopropyl-1,4-cyclohexanediones.These cyclic diketones are obtained with good yields by the Birch reduction of 2-chloromethyl-, 2,5-dichloromethyl-, and 2-isopropyl-1,4-dimethoxybenzenes.
- Russkikh, V. S.,Abashev, G. G.
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p. 742 - 745
(2007/10/02)
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