Sodium sulfide

About: Sodium sulfide is a research topic. Over the lifetime, 2851 publications have been published within this topic receiving 27733 citations. The topic is also known as: disodium sulfide.

Process for the preparation of lipoic acid and dihydrolipoic acid

Abstract: The present invention relates to a process for the preparation of R— and S-lipoic acid and R— and S-dihydrolipoic acid comprising (a) reaction of where MS is SO 2 —R′ and R and R′ independently of one another are C 1 -C 6 -alkyl, C 3 -C 8 -cycloalkyl, C 3 -C 8 -cycloalkylalkyl, aryl or aralkyl, with sodium sulfide and sulfur in methanol. The invention especially relates to processes for preparing pure R— or S-dihydrolipoic acid, which is either used directly or processed further to give R— and S-lipoic acid. The process also serves for the production of pharmaceuticals. The present invention further relates to a solution of sodium sulfide trihydrate and sulfur in methanol, the sulfur being present in a molar excess over the sodium sulfide trihydrate, and a kit which comprises the solution according to the invention.

A general synthesis of new dithiolethione derivatives: 5-(1-hydroxyimino alkyl)-1,2-dithiole-3-thiones and 5-acyl-i,2-dithiole-3-thiones

Abstract: The synthesis of 5-(1-hydroxyiminoalkyl)-1,2-dithiole-3-thiones by allowing 5-alkyl-1,2-dithiole-3-thiones to react with an excess of sodium nitrite in acetic acid and by reducing highly insoluble intermediate disulfides by sodium sulfide in a DMSO-water mixture is described. 5-(1-hydroxyimino)-1,2-dithiole-3-thiones are easily transformed into 5-acyl-1,2-dithiole-3-thiones. All yields are quite satisfactory.

Facile one-step synthesis of quaternary AgInZnS quantum dots and their applications for causing bioeffects and detecting Cu2+

Abstract: Water-soluble AgInZnS quantum dots (AIZS QDs) were synthesized with glutathione (GSH) as a stabilizer by a facile one-step method based on a hydrothermal reaction between the nitrate salts of the corresponding metals and sodium sulfide as a sulfide precursor at 110 °C. The optimal reaction conditions (temperature, time, pH, and the molar ratios of the precursors) were studied. According to the data from TEM, XPS, and XRD, AIZS QDs were characterized with excellent optical properties. The results showed that the aqueous-dispersible AIZS QDs were quasi-spherical and their average diameter was 3.51 nm. Furthermore, the cytotoxicity of AIZS QDs was investigated by microcalorimetry and microscopy techniques (confocal microscopy and TEM). The data revealed that AIZS QDs exhibited low toxicity, biocompatibility, and good water stability, due to which they could be used as a fluorescent probe for bioimaging and labeling. In addition, AIZS QDs could be used as a sensor to detect Cu2+ because the fluorescence of AIZS QDs was quenched by Cu2+.

Molybdenite alkali fusion and leaching: reactions and mechanism

Abstract: The production of MoO3 from Sarcheshmeh molybdenite concentrate via a pyro-hydrometallurgical process was studied. The molybdenite concentrate and sodium carbonate were premixed and fused under air atmosphere. Then the fused products were leached in water and the dissolved molybdenum was recovered as ammonium molybdate. The ammonium molybdate was then calcined to produce molybdic oxide. At the fusion stage, the effect of the mass ratio of carbonate to sulfide on the reaction products and the solubility of the products was investigated. The results show that during the fusion, sodium molybdate and sodium sulfate are the final reaction products and sodium sulfide is detected as an intermediate reaction product. By melting at 850°C with 5wt% excess carbonate, the maximum solubility of the products is obtained. The molybdenum is recovered from the solutions as ammonium molybdate.

Ultrafine Sodium Sulfide Clusters Confined in Carbon Nano-polyhedrons as High-Efficiency Presodiation Reagents for Sodium-Ion Batteries.

Abstract: Sodium loss at the anode in the initial sodiation process significantly reduces the energy density of sodium-ion batteries (SIBs). Here, a high-capacity Na2S/C nanocomposite featuring ultrafine Na2S nanoclusters (<2 nm) confined in ZIF-8-derived microporous N-doped carbon is fabricated and employed as a cathode presodiation reagent to compensate for this sodium loss and increase the energy density of SIBs. The ultrafine size of Na2S enables fast reaction kinetics for sodium extraction and the carbon matrix provides good electronic conductivity. Also, the overall particle size of the Na2S/C nanocomposite (∼40 nm) is close to that of conductive additive. The above features enable it to replace a partial amount of conductive additive and compensate for the sodium loss at the anode concurrently. As a demonstration, the Na3V2(PO4)3 electrode with 5 wt % Na2S/C and 5 wt % carbon black was fabricated, and it displayed a 19 mAh g-1 higher initial charge specific capacity than that of the counterpart with 10% carbon black without the addition of Na2S/C, realizing an increased energy density from 178 to 263 Wh kg-1 in the full cell configuration pairing with a hard carbon anode. Moreover, a stable cycling performance up to 200 cycles with an average capacity loss of 0.024 mAh g-1 per cycle was achieved for the presodiated Na3V2(PO4)3 electrode.