Chemical Properties
Colorless rhombic crystals. Insoluble in ethanol, readily
soluble in methanol, very readily in water. Heating with sodium
hydroxide produces sodium diamidomonothiophosphate: PS(NH2)3 +
NaOH = NaPOS(NH2)2 + NH3. Forms diammonium hydrogen monothiophosphate on standing in moist air for several weeks: PS(NH2)3 +
3H2O = (NH4)2 HPO3S + NH3. Therefore, it must be sealed in glass
for storing.
Synthesis
(1) A solution of 60 g. of freshly
distilled PSCl3 in 100 ml. of CHCl3 is added by drops to a solution
of NH3 in CHCl3; the addition time is two hours, and vigorous
stirring and efficient cooling to maintain the temperature at —15°C
are imperative. Further procedure is the same as given in method
I for phosphoryl triamide. The product (approximately 105 g.) is
treated with 225 ml. of dry CHCl3 and 100 g. of diethylamine. The
yield of crude PS(NH2)3 is approximately 32 g. Recrystallization
from methanol is effected in the same way as forPO(NH2) 3 ,
but instead of 150 or 200 ml., 100-150 ml. of solvent is used due
to the greater solubility here. The yield is 26 g. (66%).
PSCl3 + 6NH3 = PS(NH2)3 + 3NH4Cl
(2) According to Goehring and Niedenzu, PS(NH2)3 can also be produced through direct reaction of PSCl3 with liquid NH3 in the manner
described in method Ⅱ for PO(NH2)3. The Klement and Koch procedure (diethylamine) is used
to separate the products. The yield is 96%.
