SOLUBILIZATION OF SULFUR IN AMMONIA AND EQUILIBRIUM COMPOSITION OF SULFUR AMMONIA SOLUTIONS

Abstract

Sulfur ammonia solutions (SAS) were separated by anion exchange HPLC into the anions S₄N⁻ and S₃N⁻, S₃ ⁻ (and its dimer S₆ ^2-), and S_xNH⁻ ₂ (sulfur in oxidized, in reduced and in neutral form resp.). The analysis of the absorption spectra of SAS yields the concentrations of the individual components and leads to the assignement x=4 in S_xNH⁻ ₂. The time dependence of the HPLC chromatograms and of the optical spectra of freshly prepared SAS reveals that S₄NH₂ ⁻ is the primary species in the dissolution process which partly disproportionates to S₄N⁻ and S_{- 3} and to S₃N⁻ as another intermediate.

Key Words:

• Anion exchange
• HPLC
• liquid ammonia
• sulfur
• sulfur ammonia solutions
• UV/VIS spectroscopy