The tetrathionate
anion, , is a
sulfur oxyanion derived from the compound tetrathionic acid, H
2S
4O
6. Two of the sulfur
atom
Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished fr ...
s present in the ion are in
oxidation state 0 and two are in oxidation state +5. Alternatively, the compound can be viewed as the
adduct resulting from the binding of
to
SO3. Tetrathionate is one of the
polythionates, a family of anions with the formula
''n''(SO3)2sup>2−. Its IUPAC name is ''2-(dithioperoxy)disulfate'', and the name of its corresponding acid is ''2-(dithioperoxy)disulfuric acid''. The Chemical Abstracts Service identifies tetrathionate by the CAS Number 15536-54-6.
Formation
Tetrathionate is a product of the
oxidation of
thiosulfate
Thiosulfate ( IUPAC-recommended spelling; sometimes thiosulphate in British English) is an oxyanion of sulfur with the chemical formula . Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, ...
, , by
iodine, I
2:
:2 + I
2 → + 2
I−
The use of bromine instead of iodine is dubious as excess bromine will oxidize the thiosulfate to sulfate.
Structure
Tetrathionate's structure can be visualized by following three edges of a
rectangular cuboid, as in the diagram below. The structure shown is the configuration of in BaS
4O
6·2H
2O and Na
2S
4O
6·2H
2O. Dihedral S–S–S–S angles approaching 90° are common in
polysulfides.
Compounds
Compounds containing the tetrathionate anion include
sodium tetrathionate, Na
2S
4O
6,
potassium tetrathionate, K
2S
4O
6, and
barium tetrathionate dihydrate, BaS
4O
6·2H
2O.
Properties
As other species of sulfur at intermediate
oxidation state, such as thiosulfate, tetrathionate can be responsible for the
pitting corrosion of
carbon steel and
stainless steel
Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...
.
Tetrathionate has also been found to serve as a terminal electron acceptor for ''
Salmonella enterica'' serotype Typhimurium, whereas existing
thiosulfate
Thiosulfate ( IUPAC-recommended spelling; sometimes thiosulphate in British English) is an oxyanion of sulfur with the chemical formula . Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, ...
in the
small intestines of mammals is oxidized by reactive oxygen species released by the immune system (mainly
NADPH oxidase
NADPH oxidase (nicotinamide adenine dinucleotide phosphate oxidase) is a membrane-bound enzyme complex that faces the extracellular space. It can be found in the plasma membrane as well as in the membranes of phagosomes used by neutrophil white ...
produced
superoxide) to form tetrathionate. This aids in the growth of the bacterium, helped by the inflammatory response.
[Winter, Sebastian E. "Gut Inflammation Provides a Respiratory Electron Acceptor for Salmonella." ''Nature'', 23 Sept. 2010. Web. 28 Mar. 2013.]
See also
*
Corrosion
*
Dithionite
*
Polysulfides
*
Thiosulfate
Thiosulfate ( IUPAC-recommended spelling; sometimes thiosulphate in British English) is an oxyanion of sulfur with the chemical formula . Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, ...
References
Corrosion
Sulfur oxyanions
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