150-78-7Relevant articles and documents
Charge-transfer complex formations of tetracyanoquinone (cyanil) and aromatic electron donors
Jalilov, Almaz S.,Lu, Jianjiang,Kochi, Jay K.
, p. 35 - 41 (2016)
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.
Photo-Switchable Self-Assemblies Based on Thymine-Containing Bolaamphiphiles
Al-Shereiqi, Ahmed S.,Boyd, Ben J.,Saito, Kei
, p. 1135 - 1144 (2017)
The photoswitching of photosensitive bolaamphiphiles based on thymine was investigated. Topochemical principles were applied to create light-responsive supra-amphiphiles by the utilisation of dynamic covalent bonds created by the photo-dimerisation of a DNA base, thymine. In order to induce the photo-dimerisation of thymine, two bolaamphiphilic molecules were designed and synthesised to meet the required [2 π+2 π] photo-cycloaddition conditions. The amphiphiles were synthesised with different spacers and their photo-reversibility and morphologies were studied by using UV/Vis, NMR and infrared spectroscopy, rheometry, dynamic light scattering and transmission electron microscopy.
Pulse Radiolytic Investigations of Aqueous Solutions of Methoxybenzene Cation Radicals: The Effect of Colloidal RuO2
Brandys, Marek,Sasson, Richard E.,Rabani, Joseph
, p. 953 - 962 (1987)
The formation and decay of the radical cations of 1,4-dimethoxybenzene (DMB) and 1,2,4,5-tetramethoxybenzene (TMB) were investigated by the pulse radiolysis technique in the absence and the presence of colloidal RuO2 particles.DMB2. was obtained only by T12+ oxidation of DMB while TMB+.+ was produced by oxidation of TMB using both T12+ and Br2-.In the absence of RuO2 both DMB.+ and TMB.+ decay predominantly via a second-order process, although there is a contribution of a pseudo-first-order reaction.The rate constants for these reactions are reported.RuO2 colloidal particles catalyze the decay of both TMB.+ and DMB.+.The reactions of TMB.+ with RuO2 were found to depend on pH, pulse intensity, and colloidal concentration.At pH 3-4, adsorbtion of TMB.+ to the colloid is observed, followed by the decay of the remaining TMB.+ in the bulk.At higher pHs, loading of the RuO2 colloid by positive holes takes place until equilibrium is archieved between loaded holes and TMB.+ and again the remaining TMB.+ decays at a later stage.The fraction of TMB.+ that loads the colloidal particles increases with both pH and .It is also suggested that DMB.+ loads the RuO2 at the pH where experiments were performed. (TMB)2 and (DMB)2 dimers (or higher oligomers) are suggested to be the final products both in absence and presence of RuO2.No O2 is formed with the RuO2 colloid despite a favorable redox potential for water oxidation.
Photogeneration of Radical Cations from Aqueous Methoxylated Benzenes
Grabner, Gottfried,Rauscher, Walter,Zechner, Josef,Getoff, Nikola
, p. 222 - 223 (1980)
Formation of radical cations resulting from photoinduced electron ejection from methoxylated benzenes in aqueous solutions has been observed.
Hollow, mesoporous, eutectic Zn1?xMgxO nano-spheres as solid acid-base catalysts for the highly regio-selectiveO-methylation of 1,2-diphenols
Liu, Jie,Ma, Xuebing,Wang, Xuri,Xie, Guangxin,Yin, Zuyong,Zhang, Jianing
, p. 7454 - 7466 (2021/11/23)
The highly regio-selectiveO-methylation of catechol with dimethyl carbonate (DMC), catalyzed by a solid acid-base catalyst, is an environmentally friendly chemical process for industrial production of guaiacol. However, a guaiacol yield below 84% and high reaction temperature above 280 °C limit its industrial application. Here, hollow, mesoporous Zn1?xMgxO nano-spheres with a eutectic structure, denoted as Zn1?xMgxO HMNSs (x= 0.012-0.089), are facilely fabricatedviathe calcination of Mg2+/Zn2+ion-adsorbing carbon spheres at 500 °C in air. In theO-methylation of catechol with DMC at 180 °C, Zn1?xMgxO HMNSs (x= 0.052) afford guaiacol in 95.5% yield with a complete catechol conversion. Furthermore, 89.0-95.3% mono-ether yields with high 1,2-diphenol conversions (94.5-100%) are also obtained for the other 1,2-diphenols bearing -CH3and -Br groups. Moreover, a plausible mechanism for highly selectiveO-methylation of catechol with DMC is proposed, in which the single-site activation and double-site activation of phenolic hydroxyls by the basic oxygen of Mg-O afford guaiacol and veratrole, respectively.
Methylation with Dimethyl Carbonate/Dimethyl Sulfide Mixtures: An Integrated Process without Addition of Acid/Base and Formation of Residual Salts
Chan, Bun,Lui, Matthew Y.,Lui, Yuen Wai
, (2022/01/08)
Dimethyl sulfide, a major byproduct of the Kraft pulping process, was used as an inexpensive and sustainable catalyst/co-reagent (methyl donor) for various methylations with dimethyl carbonate (as both reagent and solvent), which afforded excellent yields of O-methylated phenols and benzoic acids, and mono-C-methylated arylacetonitriles. Furthermore, these products could be isolated using a remarkably straightforward workup and purification procedure, realized by dimethyl sulfide‘s neutral and distillable nature and the absence of residual salts. The likely mechanisms of these methylations were elucidated using experimental and theoretical methods, which revealed that the key step involves the generation of a highly reactive trimethylsulfonium methylcarbonate intermediate. The phenol methylation process represents a rare example of a Williamson-type reaction that occurs without the addition of a Br?nsted base.