505-73-7Relevant articles and documents
Cu(II)-catalyzed oxidation of thiols by superoxide ligated to Co III2
Mishra, Ritu,Banerjee, Rupendranath,Mukhopadhyay, Subrata
, p. 1193 - 1197 (2012)
Copper(II) dramatically catalyzes the oxidation of thiols by a superoxide bridging two CoIII ions. The catalyzed path overwhelmingly dominates over the uncatalysed path and is first order in the superoxo complex concentration. The first-order rate constants show a first-order dependence in [Cu2+], a second-order dependence in [thiol] and linearly varies with [H+]-3. On the basis of observed kinetics reported here, it is proposed that Cu(II) reacts with two thiol molecules to form a Cu II(thiol)2 complex, an electron is transferred from one ligated thiol to the CuII center to form CuI(thiol) and a thiyl radical. The copper(I)-thiol complex is oxidized by the conjugate base of the title complex to regenerate CuII(thiol). A CuII/I catalytic cycle is thus believed to be responsible for the observed catalysis. Copyright
Improvement of a process for synthesis of thioglycolic acid
Islamgulova,Shitova,Akhmerova,Tomilov
, p. 1438 - 1440 (2002)
An environmentally clean process was proposed for synthesis of thioglycolic acid by condensation of monochloroacetic acid with sodium disulfide, followed by electrochemical reduction of the resulting mixture.
Cu(II) catalyzed oxidation of mercaptoacetic acid by methylene blue in acidic medium: Influence of solvent and morphology
Sharma, Ranjana,Pal, Mahender,Mishra
, p. 41 - 47 (2016)
Kinetic studies on the Cu(II) catalyzed oxidation of mercaptoacetic acid (thioglycolic acid, TGA) by the model electron receptor methylene blue in acidic medium show that the reaction follows a second order kinetics in TGA. The order in methylene blue is unity but at higher [TGA], the order is 3/4. The rate shows an inverse relationship with [H+] and a second order dependence on [Cu(II)]. The reaction conforms to Arrhenius behavior in aqueous medium but resorts to anti-Arrhenius behavior in aqueous methanol and in aqueous acetone media. The reaction involves the in situ participation of nanoparticles which has been confirmed by SEM, XRD, and FTIR techniques. In aqueous medium, cauliflower shaped nanoparticles (44.21-74.33 nm) are obtained but in the presence of acetone and methanol, nanogranules (38.96-70.73 nm) and nanodisks (47.30-72.16 nm), respectively, are produced at 35°C as revealed by SEM images and XRD data. The reaction is characterized by the participation of two transition states in aqueous acetone medium and the kinetics of the reaction, especially the temperature dependence, is governed by the adsorption of methylene blue on copper nanoparticles as influenced by morphology inter alia dielectric constant of the reaction medium.
Determination of Thioglycolic Acid and Dithiodiglycolic Acid in Mineral Flotation Systems
McLean, McLean,Wagenen, Stan Van,Wiedemann, Donna,Fernando, Quintus,Raghavan, Srini
, p. 965 - 969 (1986)
When aqueous solution of thioglycolic acid are equilibrated with sphalerite, a zinc sulfide mineral, a large fraction of the thioglycolic acid is either adsorbed on the sphalerite surface or oxidized ot dithiodiglycolic acid.The total concentration of thioglycolic and dithioglycolic acid in solution has been determined by molecular emission cavity analysis (MECA).The fraction of the thioglycolic acid that is not adsorbed on the mineral surface and remains in solution has been determined by a coulometric titration in which iodine is electrogenerated in situ and the endpoint located by an amperometric method.Attempts to determine the thioglycolic acid that was adsorbed on the mineral surface directly by MECA gave unreliable results.This has been attributed to the wide variation in the surface area as well as the surface chemical composition of small samples (1-2 mg) of the mineral that must be useed in the sample cup in MECA.Thioglycolic acid also leaches traces of metal ions from the mineral surface.The concentration of zinc(II) in solution reflects the extent of leaching that has occurred.
Soft template induced phase selective synthesis of Fe2O3 nanomagnets: One step towards peroxidase-mimic activity allowing colorimetric sensing of thioglycolic acid
Roy, Anindita,Sahoo, Ramkrishna,Ray, Chaiti,Dutta, Soumen,Pal, Tarasankar
, p. 32308 - 32318 (2016)
Different Schiff's base (SB) templates have been obtained to mediate phase selective synthesis of α- or γ-Fe2O3 from the same temperature condition. The inherent phase transformation tendency (γ-Fe2O3 to α-Fe2O3) is found to be inhibited. Again, the phase selective evolution emerges out of the binding modes of SBs which has been illustrated here. The nature of SBs governs the shape and size distribution of Fe2O3 NPs. As both the phases are magenetically active, easy magnetic separation of them widens their applicability in catalysis. Magnetically active both α- and γ-Fe2O3 mimic interesting peroxidase like activity by oxidising colourless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue coloured oxidised product (Ox-TMB) in aqueous H2O2. These results prompted us to improvise further to detect thioglycolic acid (TGA) at a micromolar level which provides commercial applicability.
l-Arginine complex of copper on modified core–shell magnetic nanoparticles as reusable and organic–inorganic hybrid nanocatalyst for the chemoselective oxidation of organosulfur compounds
Nikoorazm, Mohsen,Moradi, Parisa,Noori, Nourolah,Azadi, Gouhar
, p. 467 - 478 (2020/09/01)
In this paper, we report the fabrication and characterization of a stable heterogeneous nanostructure catalyst of copper immobilized on Fe3O4@SiO2@l-Arginine, for the oxidation of sulfides and oxidative coupling of thiols. The prepared nanocatalyst has been characterized by different techniques such as FTIR, XRD, SEM, TEM and TGA. These nanoparticles were the effective catalyst for selective oxidation of sulfides and oxidative coupling of thiols using 30% H2O2. The suggested method offers several prominent advantages such as mild condition, use of magnetically reusable catalyst, simple workup procedure, good to high yields of products and great selectivity.
Synthesis and Characterization of Magnetic Functionalized Ni and Cu Nano Catalysts and Their Application in Oxidation, Oxidative Coupling and Various Multi-Component Reactions
Hajjami, Maryam,Sheikhaei, Shiva,Gholamian, Fatemeh,Yousofvand, Zakieh
, p. 2420 - 2435 (2021/01/04)
Abstract: Two magnetic nano catalysts of nickel and copper, Fe3O4@SiO2@DOP-BenPyr-M(II), (M=Ni and Cu) have been synthesized. These catalysts were applied as recoverable, efficient and new heterogeneous catalysts for the high yielding and room temperature one-pot procedure of selective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to disulfides. In addition, the catalytic activity of Fe3O4@SiO2@DOP-BenPyr-Ni(II) was investigated as heterogeneous nanocatalyst for synthesis of 2,3-dihydroquinazolin-4(1H)-ones, 5-substituted 1H-tetrazoles and polyhydroquinolines. The synthesized catalysts were characterized by FT-IR, TGA, XRD, VSM, EDX, ICP and SEM techniques. These catalysts were recovered by an external magnet and reused several times without significant loss of catalytic efficiency. Graphic Abstract: [Figure not available: see fulltext.]
Fe3O4@MCM-41@Zn-Arg: as a novel, magnetically recoverable and ecofriendly nanocatalyst for the synthesis of disulfides, sulfoxides and 2,3-dihydroquinazolin?4(1H)?ones
Nikoorazm, Mohsen,Erfani, Zahra
, p. 642 - 655 (2020/08/19)
The direct supporting of Zn-arginine complex on magnetic core-shell nanostructures (Fe3O4@MCM-41@Zn-Arg) was reported as a novel, heterogeneous and excellent nanocatalyst, which applied for the oxidation reaction of sulfides to sulfoxides, oxidative coupling of thiols to their corresponding disulfides and the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives under mild conditions. The structure of the catalyst was studied by X-Ray diffraction, Fourier transform-infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, atomic absorption spectroscopy, and vibrating sample magnetometry techniques. The simple experimental procedure, very good catalytic activity, low cost, and excellent recycling are the noteworthy features of the currently employed heterogeneous catalytic system.
Synthesis and characterization of VO–vanillin complex immobilized on MCM-41 and its facile catalytic application in the sulfoxidation reaction, and synthesis of 2,3-dihydroquinazolin-4(1H)-ones and disulfides in green media
Nikoorazm, Mohsen,Khanmoradi, Maryam
, p. 1477 - 1489 (2020/03/11)
In this work, a vanillin complex is immobilized onto MCM-41 and characterized by FT-IR, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, and BET techniques. This supported Schiff base complex was found to be an efficient and recoverable catalyst for the chemoselective oxidation of sulfides into sulfoxides and thiols into their corresponding disulfides (using hydrogen peroxide as a green oxidant) and also a suitable catalyst for the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives in water at 90°C. Using this protocol, we show that a variety of disulfides, sulfoxides, and 2,3-dihydroquinazolin-4(1H)-one derivatives can be synthesized in green conditions. The catalyst can be recovered and recycled for further reactions without appreciable loss of catalytic performance.
SUPER-HYDROPHOBIC ELECTROTHERMAL EPOXY RESIN COMPOSITE MATERIAL AND PREPARATION AND SELF-REPAIRING METHOD THEREFOR
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, (2020/12/25)
Superhydrophobic electrothermal epoxy composites, their preparation and a self-healing method are disclosed. 1,4,5-oxadithiepane-2,7-dione and methylhexahydrophthalic anhydride were mixed and cured with epoxides to get self-healable epoxy resins; carbon nanotube/self-healable epoxy resin prepolymers were coated on self-healable epoxy resins and cured to get electrothermal epoxy composites; modified superhydrophobic copper powders were adhered on electrothermal epoxy composites and cured to get a kind of superhydrophobic electrothermal epoxy composites. The thermal resistance of superhydrophobic electrothermal epoxy composites is superior to existed technical solutions and they can simultaneously repair cracking and delamination and the healed samples still exhibit excellent superhydrophobicity. These merits of superhydrophobic electrothermal epoxy composites provided in this invention can meet the harsh requirements of self-healing and removing ice on surfaces of wind turbine blades, suggesting good abilities of guaranteeing service safety and lifespan of wind turbine blades.
