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Sodium polysulfide is a general term for salts with the formula Na 2 S x, where x = 2 to 5. The species S x 2−, called polysulfide anions, include disulfide (S 2 2−), trisulfide (S 3 2−), tetrasulfide (S 4 2−), and pentasulfide (S 5 2−). In principle, but not in practice, the chain lengths could be longer.
The compound (C 5 H 5) 2 TiS 5 is an example of a polysulfide complex. Polysulfides are a class of chemical compounds derived from anionic chains of sulfur atoms. [1] There are two main classes of polysulfides: inorganic and organic. The inorganic polysulfides have the general formula S 2− n. These anions are the conjugate bases of ...
Potassium pentasulfide is the inorganic compound with the formula K 2 S 5. It is a red-orange solid that dissolves in water. It is a red-orange solid that dissolves in water. The salt decomposes rapidly in air.
Reduction of sulfur gives various polysulfides with the formula S x 2-, many of which have been obtained crystalline form. Illustrative is the production of sodium tetrasulfide: 4 Na + S 8 → 2 Na 2 S 4. Some of these dianions dissociate to give radical anions, such as S 3 − gives the blue color of the rock lapis lazuli.
The rank x of the polysulfide is an important variable. [vague] Crosslinking agents are used, such as 1,2,3-trichloropropane. An idealized polymer is represented by this formula HS(CH 2 CH 2 OCH 2 OCH 2 CH 2 SS) n CH 2 CH 2 OCH 2 OCH 2 CH 2 SH. Thiol-terminated resins can be cured oxidatively. [2]
"Thiokol" polymers arise when sodium polysulfide is treated with an alkyl dihalide. In the converse reaction, carbanionic reagents react with elemental sulfur to afford mixtures of the thioether, disulfide, and higher polysulfides. These reactions are often unselective but can be optimized for specific applications.
Hydrogen disulfide can be synthesised by cracking polysulfanes (H 2 S n) according to this idealized equation: H 2 S n → H 2 S 2 + S n−2. The main impurity is trisulfane (H 2 S 3). [1] The precursor polysulfane is produced by the reaction of hydrochloric acid with aqueous sodium polysulfide. The polysulfane precipitates as an oil. [1] [2]
where and are the molar weighted segment and area fractional components for the -th molecule in the total system and are defined by the following equation; is a compound parameter of , and . z {\displaystyle z} is the coordination number of the system, but the model is found to be relatively insensitive to its value and is frequently quoted as ...