Formula Na3PO3S Appearance Crystalline white solid | Molar mass 180.03 g/mol | |
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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.
Preparation
Sodium monothiophosphate is created via the reaction between thiophosphoryl chloride and sodium hydroxide according to the method of Yasuda and Lambert.
PSCl3 + 6 NaOH → Na3PO3S + 3 NaCl + 3 H2OThe 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 the pH is altered.