Search results for "oxalic acid."
showing 10 items of 59 documents
[Cu3(Hmesox)3]3−: a Precursor for the Rational Design of Chiral Molecule-Based Magnets (H4mesox = 2-dihydroxymalonic acid)
2010
Two new compounds K(3)[Cu(3)(Hmesox)(3)(H(2)O)] x 4 H(2)O (1) and {(PPh(4))(2)[CoCu(3)(Hmesox)(3)Cl]} (2) [H(4)mesox = mesoxalic acid (2-dihydroxymalonic acid) and PPh(4)(+) = tetraphenylphosphonium cation] have been prepared and magneto-structurally characterized. Compound 1 contains the [Cu(3)(Hmesox)(3)](3-) entity which can be considered as a new precursor for molecular magnetism. In 1 the triangular arrangement of three copper(II) ions bridged by alkoxo groups are further connected to a symmetry-related tricopper(II) unit through a double oxo(carboxylate) bridge. The resulting hexacopper(II) entities are joined further through anti-syn carboxylate groups into an anionic three-dimension…
An electrochemical process to prepare and recycle biobased ionic liquids
2019
This manuscript describes the first electrosynthesis of biobased ionic liquids from L-valine, oxalic acid and glyoxal, which is energy-efficient, does not emit toxic waste and avoids the formation of inorganic waste. These ionic liquids were then used in the development of our electro-recycling process. While their recycling yields are still moderated due to recombination and disproportionation reactions, this unprecedented recycling technology is very promising in terms of environmental and economic gains. Indeed, it has a high energy efficiency, requires low cost equipment, allows a strong decrease of the price of such ionic solvents, limits the use of non-renewable resources and solves t…
The influence of thickness, interpore distance and compositional structure on the optical properties of self-ordered anodic aluminum oxide films
2016
Highly ordered anodic aluminum oxide (AAO) films were fabricated using a two-step anodization process in oxalic acid, sulfuric acid, or ethylene glycol containing sulfuric acid, which are important in design of nanostructured optical devices. The morphology and UV-Vis reflectance spectroscopy of these films were analyzed. The morphological parameters of the AAO films, such as the thickness, pore diameter, interpore distance, porosity, pore arrangement regularity, and anodization electrolyte, were adjusted in order to study the effect of these parameters on the UV-Vis reflectance properties of these films. Raman spectroscopy measurements were then utilized to better understand the chemical d…
Total oxidation of VOCs on mesoporous iron oxide catalysts: Soft chemistry route versus hard template method
2016
9 figures, 3 tables.-- Supplemantary information available
Electrochemical oxidation of organics at metal oxide electrodes: The incineration of oxalic acid at IrO2-Ta2O5 (DSA-O2) anode
2008
Abstract The electrochemical incineration of oxalic acid (OA) at Ti/IrO2–Ta2O5 (DSA-O2) anode was investigated to find the influence of the operative parameters on the performances of the process. Polarization curves and chronoamperometric measurements indicate the probable occurrence of a direct electrochemical oxidation of OA at the surface of the DSA anode. In incineration electrolyses, the performances of the process in terms of OA conversion and current efficiency dramatically depend on the adopted operative conditions. Interestingly, very high OA removal and current efficiency were obtained when the process was performed at relatively high temperatures (50 °C) or in the presence of Na…
Rapid and direct gas chromatographic determination of oxalic acid in urine
1979
The known methods of oxalic acid determination are not suitable for reliable, rapid and economical routine analysis. A rapid gas chromatographic method has been developed which dispenses with separation operations and measures oxalic acid as a diethylester by means of back-flushing, and using malonic acid as an internal standard. One determination can be conducted within 6 to 8 min. and preparation of the specimen takes about the same amount of time. If the gas chromatographic conditions are changed and more time is permitted for analysis, numerous other extractable acidic metabolites can also be determined.
Selective and sensitive colorimetric detection of the neurotransmitter serotonin based on the aggregation of bifunctionalised gold nanoparticles
2018
[EN] We report a simple, sensitive and selective method for the colorimetric detection of serotonin (5-HT) in aqueous media using bifunctionalized gold nanoparticles (AuNPs). The probe (1) consisted of AuNPs functionalised with dithiobis(succinimidylpropionate) (DSP) and N-acetyl-l-cysteine (NALC). DSP was chosen to react with the amino group of 5-HT, whereas NALC was chosen to bind the hydroxyl group in 5-HT through hydrogen bonding and electrostatic interactions. A double interaction between nanoparticles and the hydroxyl and the amino group of serotonin led to interparticle-crosslinking aggregation. This, resulted in a colour change from red to blue that can be observed by the naked eye.…
Direct nucleation of calcium oxalate dihydrate crystals onto the surface of living renal epithelial cells in culture
1998
Direct nucleation of calcium oxalate dihydrate crystals onto the surface of living renal epithelial cells in culture. Background. The interaction of the most common crystal in human urine, calcium oxalate dihydrate (COD), with the surface of monkey renal epithelial cells (BSC-1 line) was studied to identify initiating events in kidney stone formation. Methods. To determine if COD crystals could nucleate directly onto the apical cell surface, a novel technique utilizing vapor diffusion of oxalic acid was employed. Cells were grown to confluence in the inner four wells of 24-well plates. At the start of each experiment, diethyloxalate in water was placed into eight adjacent wells, and the pla…
A solution study of complex formation between iron(III) and oxalate in dimethylsulphoxide
1991
The complex formation between iron(III) and oxalic acid (ethanedioic acid, H2ox) has been studied by potentiometry in dimethylsulphoxide (dmso) solution. H2ox behaves as a weak diprotic acid in such a solvent, with overall association constants: log βj1=8.551(3) and log βj2=14.242(3) at 25°C and 0.1 Mn-Bu4NClO4. A reliable set of overall stability constants for the iron(III)-oxalato complexes, log β11=13.16(4), log β12=23.66(4) and log β13=30.75(4), have been obtained for the first time under identical conditions. The electrochemical behaviour of such complexes was studied in dmso at a platinum electrode. The coordination ability of oxalate towards iron(III) in dmso and water media is compa…
Sialic acid-containing glycoproteins on renal cells determine nucleation of calcium oxalate dihydrate crystals
2001
Sialic acid-containing glycoproteins on renal cells determine nucleation of calcium oxalate dihydrate crystals. Background The interaction between the surfaces of renal epithelial cells and calcium oxalate dihydrate (COD), the most common crystal in human urine, was studied to identify critical determinants of kidney stone formation. Methods A novel technique utilizing vapor diffusion of oxalic acid was employed to nucleate COD crystals onto the apical surface of living cells. Confluent monolayers were grown in the inner 4 wells of 24-well culture plates. To identify cell surface molecules that regulate crystal nucleation, cells were pretreated with a protease (trypsin or proteinase K) to a…