A selenophosphate is a chemical compound containing

phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s substituted with

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

. Over 7000 compounds are known with a bond between selenium and phosphorus. Compared to phosphorus-sulfur compounds selenophosphates are less thermally stable, and more easily destroyed by water. However they are more stable than tellurophosphates which have an even weaker phosphorus-tellurium bond. Selenophosphates have an oxidation number for phosphorus of +5. But in many there are bonds between phosphorus atoms, reducing the oxidation state to +4, Some may be termed selenophosphites. Different structural anions include hexaselenohypodiphosphate ₂Se₆sup>4− and ₆Se₁₂sup>4− with decalin structure and ₄Se₂sup>2− with dicyclobutane structure. Selenophosphates are coloured, often orange. They are semiconductors. The first selenodiphosphate was discovered in 1973 by H. Hahn. Selenophosphate compounds may have some or all of the selenium replaced by sulfur.

Formation

Selenophosphates can be produced by melting

phosphorus selenide Phosphorus selenides are a relatively obscure group of compounds. There have been some studies of the phosphorus - selenium phase diagram and the glassy amorphous phases are reported. The compounds that have been reported are shown below. While some ...

with metal

selenides A selenide is a chemical compound containing a selenium with oxidation number of −2. Similar to sulfide, selenides occur both as inorganic compounds and as organic derivatives, which are called organoselenium compound. Inorganic selenides Th ...

Molecular biology

Selenocysteine Selenocysteine (symbol Sec or U, in older publications also as Se-Cys) is the 21st proteinogenic amino acid. Selenoproteins contain selenocysteine residues. Selenocysteine is an analogue of the more common cysteine with selenium in place of the ...

is produced in many organisms from a selenophosphate. In humans and other eucaryotes, this is facilitated by the enzyme selenophosphate synthetase 1. Selenium is connected to phosphorus using a reaction with selenide and

adenosine triphosphate Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides energy to drive and support many processes in living cell (biology), cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known ...

List

References

Extra reading

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