Strontium Ammonium, Sr(NH₃)₆

Strontium Ammonium, or Strontium Hexammoniate, Sr(NH₃)₆, is prepared by the action of dry ammonia on pure strontium cooled to -60° C. Excess of ammonia produces a dark blue liquid, which, on evaporation in vacuo, gives off ammonia and deposits bronze-coloured crystals. The tension of dissociation is 42.2 mm. at 0° C. and 275 mm. at 33.5° C. Oxygen acts upon a solution of the compound in ammonia at -55° to -40° C., with the formation of a mixture of oxide and peroxide.

The heat of formation of strontium hexammoniate from the metal and ammonia is 9.90 Cal.