Identification of the Products of the Reaction between Sulfur and Sodium Carbonate

Abstract

The reaction between sulfur and sodium carbonate at 350 °C has been investigated, and the products of the reaction have been identified at room temperature by using IR and Raman spectroscopies. The reaction is a disproportionation of sulfur in sodium thiosulfate (oxidized species) and in a polysulfide (reduced species). When sodium carbonate is in excess ([S]/[Na2CO3] < 3.3) only one polysulfide, S4 2-, is formed, but when sulfur is in excess, only S5 2- is observed.

Multifrequency electron paramagnetic resonance of ultramarine blue

“…When formed in alkali halide crystals, the S3 radical has a rhombic g factor, with the smallest g dispersion being in NaCl: g., = 2.0465, gom, = 2.0308, and g2Z = 2.0014 and the largest g dispersion being in KBr: g., = 2.0508, gom, = 2.0327, and g., = 2.0004 [9]. The g dispersion of S3 in quenched molten Na2S + 5S was g, = 2.0029, g2 = 2.0325, and g3 = 2.0488 [19]. This range of g factors would correspond to an overall powder spectrum width of ca.…”

“…Impurities are also observed in the EPR spectra. For example, in some ultramarine green pigments EPR signals due to iron have been observed [13]. The goal of the present study is to explore the nature of the spectrum of the radical in ultramarine blue by continuous-wave (CW) EPR over a wider range of microwave frequencies and sample temperatures than have been used previously to better define the magnitude of the exchange interaction.…”

Encapsulation of red sulfur chromophores in a zeolitic imidazolate framework (ZIF-8) via solvent assisted linker exchange

“…[41,53,54]. The cis S 4 chain which is responsible for the red color [6,16,18,19,41,54] is known to be the most stable isomer followed by the trans isomer [54]. Since S 4 and S 4 À are red, the XPS spectrum was collected to better identify the sulfur species present.…”

“…A red shade seen in some ultramarines is due to the presence of the neutral S 4 molecule [6,16,18]. A deep blue colored solution is obtained when yellow polysulfides are dissolved in electron pair donor (EPD) solvents such as dimethylformamide (DMF) and dimethylsulfoxide (DMSO) [16,19].…”

Synthesis of Ultramarine from Reservoir Silts

“…An aliquot of sodium carbonate (reagent grade, Fisher Scientific, Leicestershire, UK) solution of assigned concentrations was slowly added to the powder and was hand-kneaded to balls and then dried in air. It was reported [29,30] that in the reaction, sulfur and sodium carbonate are reacted as: 3Na 2 CO 3 + 1.25S 8 ↔ 2Na 2 S 4 + Na 2 S 2 O 3 + 3CO 2 (1)…”