Sodium monothiophosphate

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Sodium monothiophosphate
Molecular model of sodium monothiophosphate
IUPAC name Sodium monothiophosphate
Properties
Molecular formula Na3PO3S
Molar mass 180.03 g/mol
Appearance Crystalline white solid
Melting point

120-125 °C (decomposition)

Solubility in water Miscible
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Sodium monothiophosphate, or sodium phosphorothioate, is a chemical compound with the molecular formula Na3PO3S. It is a crystalline white solid that decomposes without melting at 120-125 °C.

[edit] Preparation

Sodium monothiophosphate is created via the reaction between thiophosphoryl chloride and sodium hydroxide according to the method of Yasuda and Lambert.[1]

PSCl3 + 6 NaOH → Na3PO3S + 3 NaCl + 3 H20

The yield depends on the purity of the sodium hydroxide. Also, sodium phosphorothiolate decomposes at neutral pH and so it was found that using an excess of sodium hydroxide will allow for a greater yield since the reaction will not near a neutral pH. Also, it was noted that silicone grease catalyses the hydrolysis of the phosphorothioate ion, so it is recommended that it is not used in the glass joints. The reported average yield was 59% and it is possible to get higher if you tweak the pH.[2]

[edit] References

  1. ^ S. K. Yasuda and J. L. Lambert, Inorganic Syntheses, 5, 102 (1957).
  2. ^ L. C. Washburn and R. L. Hayes, Inorganic Syntheses, 17, 193