Hubbry Logo
search
logo
2056510

Polysulfide

logo
Community Hub0 Subscribers
Write something...
Be the first to start a discussion here.
Be the first to start a discussion here.
See all
Polysulfide

Polysulfides are a class of chemical compounds derived from anionic chains of sulfur atoms. There are two main classes of polysulfides: inorganic and organic. The inorganic polysulfides have the general formula S2−
n
. These anions are the conjugate bases of polysulfanes H2Sn. Organic polysulfides generally have the formulae R1SnR2, where R is an alkyl or aryl group.

The alkali metal polysulfides arise by treatment of a solution of the sulfide with elemental sulfur, e.g. sodium sulfide to sodium polysulfide:

S2−
+ n S → S2−
n+1

In some cases, these anions have been obtained as organic salts, which are soluble in organic solvents.

The energy released in the reaction of sodium and elemental sulfur is the basis of battery technology. The sodium–sulfur battery and the lithium–sulfur battery require high temperatures to maintain liquid polysulfide and Na+-conductive membranes that are unreactive toward sodium, sulfur, and sodium sulfide.

Polysulfides are ligands in coordination chemistry. Examples of transition metal polysulfido complexes include (C5H5)2TiS5, [Ni(S4)2]2−, and [Pt(S5)3]2−. Main group elements also form polysulfides.

In commerce, the term "polysulfide" usually refers to a class of polymers with alternating chains of several sulfur atoms and hydrocarbons. They have the formula R1SnR2. In this formula n indicates the number of sulfur atoms (or "rank"). Polysulfide polymers can be synthesized by condensation polymerization reactions between organic dihalides and alkali metal salts of polysulfide anions:

n Na2S5 + n ClCH2CH2Cl → [CH2CH2S5]n + 2n NaCl

See all
User Avatar
No comments yet.